Karen Par

Silva Zulay

Vargas

Président Sébastien

Professeur Paul

Fongarland Pascal

Professeur Anne-Cecile Roger

Sébastien

MCF Araque Marin

Karen Zulay

Centrale Lille

De Jeriffa

Clerq

Benjamin Katryniok

Discipline : Molécules et matière condensée Spécialité: Catalyse Hétérogène

SMRE-104 PhD school

Vas-y , on peut tout ! Vamos, podemos hacer cualquier cosa ! I'd like to send my most heartfelt gratitude to my family for their constant support, mainly

i Résumé L'utilisation de ressources durables telles que la biomasse a augmenté et devient de plus en plus importante dans la production de produits chimiques. Les composés oléfiniques sont une cible intéressante dû à son rôle de molécule plateforme pour approvisionner ce grand marché actuellement fourni à partir de ressources pétrolières. Parmi ceux-ci, l'alcool allylique est une molécule plateforme intéressante en raison de sa large gamme d'applications. Ses dérivés sont présents dans les parfums, les produits pharmaceutiques, les formulations alimentaires, les plastifiants, les agents de réticulation et les additifs d'enrobage. Parmi les différentes voies biosourcées pour la synthèse d'alcool allylique, celles qui sont issues du glycérol sont particulièrement avantageuses. Le glycérol est le principal sous-produit de l'industrie du biodiesel considéré comme une matière première dotée d'un réel potentiel au plan commerciale dans le domaine de la bioraffinerie.

La désoxydehydratation (DODH) du glycérol semble actuellement la méthode la plus compétitive pour synthétiser l'alcool allylique. Cette réaction consiste à éliminer deux groupes hydroxyles vicinaux d'un diol ou d'un polyol pour donner l'alcène correspondant (liaison C=C).

De plus, elle nécessite un réducteur stoechiométrique, qui est oxydé pendant la réaction. Le développement de la réaction DODH est lié à l'implémentation d'un système catalyseur/réducteur optimal. Une grande diversité catalyseurs pour le DODH du glycérol a été rapportée dans la littérature. D'ordre général, les systèmes à base de métal présent une meilleure activité et stabilité pendant la réaction. Les métaux les plus étudiés sont le rhénium, le molybdène, le fer et le vanadium en combinaison avec un donneur d'hydrogène comme le PPh3 et les alcools à chaîne longue (charbon> 5). En général, le système catalyseur/réducteur basé sur l'oxyde de rhénium et d'alcools secondaires montre la meilleure performance catalytique dans des conditions de réaction relativement douces (T=140-170°C et P=<5bar), avec la possibilité de valoriser le cétone co-produit. Les supports tels que le dioxyde de titane (TiO2), la cérine (CeO2) et l'alumine (Al2O3) sont les plus répandus quant à leur stabilité. Jusqu'à présent, cette réaction a été très peu étudiée d'où la recherche d'un système catalytique complet, autrement dit, stable, d'haute performance, y compris le donneur d'hydrogène et son système de séparation, reste encore un objective à aboutir. Le but de cette thèse était de développer un procédé intégré pour la synthèse d'alcool allylique via DODH de glycérol en utilisant un alcool secondaire comme solvant-réducteur, y compris la conception du catalyseur, le procédé de séparation et la modélisation correspondant du procédé.

Le catalyseur est basé sur l'oxyde de rhénium supporté sur cérine. Ce dernier a été au centre de cette étude en raison de la présence d'espèces hautement réductibles tels que Ce 4+ /Ce 3+ , la forte présence de défauts de surface ainsi que de propriétés acido-basiques, faisant de ce matériau, un support idéal pour la réaction de désoxydehydratation. CeO2 a été synthétisé à travers du processus de nanocasting en utilisant de la silice et du charbon actif comme agents structurants. La cérine commercial (CeO2-HSA) a fait également partie de cette étude. Les supports en cérine ont été imprégnés avec ReOx et appliqués pour la réaction DODH du glycérol en alcool allylique avec d'excellents rendements allant jusqu'à 86%, en utilisant un 2-hexanol ou 4-méthylpentan-2-ol (MIBC) comme donneur d'hydrogène et solvant. Ce catalyseur était réutilisable pendant 3 cycles sans réactivation intermédiaire. Aucun signe de lixiviation n'a été observé, ce qui confirme la nature hétérogène de la réaction catalytique. La présence d'une matrice de silice issue la synthèse du support CeO2, n'a montré aucun effet négatif pour la réaction, indiquant qu'il est possible d'obtenir la même performance catalytique avec un support commercial (CeO2-HSA) qu'avec le support CeO2-SiO2. En revanche, une élimination partielle de la matrice de silice -81% pour le SBA-15 et 57% pour le SiO2 -par traitement au NaOH, diminuait le rendement en alcool allylique d'environ 14%. Aucune influence des propriétés texturales du support sur la performance catalytique n'a été mise en évidence, la diminution de l'activité catalytique lors de l'élimination de la matrice d'environ 14% a été attribuée alors aux modifications des propriétés redox du support, montant une augmentation du rapport Ce 3+ /Ce 4+ dans tous les catalyseurs traités par le NaOH. De la même manière, cette étude a montré que les deux couples redox Re 7+ /Re 5+ et Re 6+ /Re 4+ sont impliqués durant la conversion de glycérol en alcool allylique au cours de la réaction DODH.

En ce qui concerne le développement du procédé intégré, la distillation atmosphérique a été choisie pour la séparation des mélanges liquides. Elle est basée sur l'équilibre liquidevapeur (VLE). Ces données d'équilibre ont été déterminées pour les principaux systèmes binaires isobares afin de modéliser la colonne de distillation, correspondant aux mélanges alcool allylique/2-hexanol, alcool allylique/MIBC, alcool allylique/2-hexanone, alcool allylique/MIBK, 2-hexanol/2-hexanone et MIBK/MIBC. 2-hexanol et MIBC sont les solvants, iii La modélisation intégrée du procédé de production l'alcool allylique à partir de glycérol, y compris le procédé de séparation, a été réalisée avec le logiciel Aspen Plus V11. Le procédé a été conçu pour un débit de glycérol de 1kmol/h et un rendement de réaction de 96%. Deux différents scenarios ont été proposés : l'utilisation de 2-Hexanol et MIBC comme donneurs d'hydrogène. Les paramètres cinétiques de la réaction DODH ont été déterminés expérimentalement pour les deux solvants. En comparaison, le taux de réaction avec le 2hexanol était presque deux fois plus élevé que pour le MIBC, ce qui implique une cuve de réaction plus grande pour le MIBC. Pour optimiser le volume de réaction, un système en cascade de 5 réacteurs agités a été implémenté dans la simulation. Par la suite, la séparation et la purification du produit ont été réalisées par distillation atmosphérique et distillation extractive, respectivement. Compte tenu de la nature de chaque solvant et du correspondant cétone coproduite, la conception de la séparation des produits été focalisée sur la réduction de la perte de solvant pour le procédé 2-Hexanol, tandis que pour le procédé MIBC, la récupération/purification maximal de MIBK a été le principal objectif. Pour le procédé 2hexanol, en respectant les principes de la chimie verte et de l'économie du carbone, une régénération du 2-hexanol a été proposée. La réaction correspondante a été étudiée au laboratoire à l'aide d'un catalyseur d'hydrogénation commercial afin d'obtenir des données pour la simulation. D'autre part, pour le procédé MIBC, la séparation du MIBK a été réalisé via distillation atmosphérique, en utilisant deux stratégies différentes : i) Purification directe du MIBK suite à la réaction DODH et ii) Recyclage de la mélange MIBC/MIBK dans le réacteur afin d'augmenter la concentration en MIBK avant purification. Dans ce dernier cas, des données expérimentales ont été acquises pour étudier l'impact d'une faible quantité de MIBK dans la réaction DODH. Toutes les stratégies proposées ont permettait d'obtenir l'alcool allylique avec une pureté de 99,99% (débit d'environ 55 kg/h). Par rapport au procédé 2-hexanol, un rendement global relativement élevé (OPY) a été obtenu (75,6 % contre 45 % dans le procédé MIBC). En revanche, l'utilisation du MIBC est plus favorablenotamment dû au fait que la 4méthyl-2-pentanone (MIBK) a été obtenue comme coproduit. Cependant, en raison de la forte demande énergétique, requise pour la purification directe du MIBKà cause de la faible volatilité relative du mélange binaire MIBK/MIBC (1,49 < αMK/MB < 1,76) -le recyclage du MIBK a été implémenté comme approche alternative. Ce dernier a permis de réduire la consommation d'énergie 22%, notamment grâce à une colonne de purification de MIBK plus petite (8 étages). Comparant tous les scénarios, le procédé MIBC se présente comme une stratégie faisable d'un point de vue technique et qui pourrait potentiellement servir comme point de départ pour le développement du procédé DODH à grande échelle.

General Introduction

The use of sustainable resources such as biomass has increased and becomes more and more important in the production of chemicals. Olefinic compounds are an attractive target since they are important platform chemicals, which today are still mainly obtained from petroleum resources. Among those, Allyl alcohol is a promising platform molecule due to its broad range of applications. Its derivatives are present in resins, pharmaceutical products, perfumes and food formulation. Furthermore, Allyl alcohol is considered as a promising starting material of important intermediates for the chemical industry such as acrylonitrile, acrolein and acrylic acid (Figure 1). Among the various bio-based pathways to Allyl alcohol, those starting from glycerol are particularly interesting [1][2] [3] . In fact, Glycerol is the main by-product of biodiesel industry.

Glycerol is an oxygen-rich molecule, with poor solubility in organic solvents and a relative thermal instability [3] . It is also considered as a potential biorefinery feedstock to develop various processes of valuables chemicals. With the growing demand for sustainability, an increased attention for Glycerol conversion toward less oxygenated derivatives has been observed. With respect to its transformation to allyl alcohol, research has been focused on the selective oxygen removal via the deoxydehydration reaction (DODH), a very competitive methodology which has been poorly investigated [3][4] [5] .

Figure 1. Schema of the production of important intermediates of the chemical industry using allyl alcohol as main source.

I. Deoxydehydration reaction (DODH)

The Deoxydehydration reaction consist in the removal of two vicinal hydroxyl groups from a diol or polyol to yield the corresponding alkene (C=C bond). Figure 2 displays the case of DODH of Glycerol to Allyl alcohol. This reaction requires a stoichiometric reductant (red), which is oxidized during the reaction (redO) [6] .

HO OH OH OH H 2 O + Catalyst Red RedO Glycerol Allyl alcohol
Figure 2. General reaction pathway for the deoxydehydration reaction. Red=reductant. RedO=oxidised reductant [6] .

A large diversity of catalytic process of DODH of glycerol have been reported in literature, including metal-free and transition metal based catalysts. Research of an optimal reductant and catalyst has become a subject of great interest. In the following section, we summarize some examples of these studies.

I.1. Non-catalytic DODH: Formic acid (FA) and Thriethyl orthoformate

As presented in Table 1 (entries 1-5), under non-catalytic reaction conditions, formic acid (FA)

and thriethyl orthoformate-assisted DODH strategies have been the major approaches. In 2009, Arceo et al. [7] carried out the production of Allyl alcohol from glycerol with a yield of 80% under nitrogen atmosphere and heating in a temperature range between 230 and 240°C. Inert atmosphere was used instead of air, in order to avoid side-reactions. Cycles of distillationcooling allowed the reaction to proceed until complete conversion by continuously removing the product (Allyl alcohol). The authors suggested that the FA-mediated didehydroxylation provides a one-step mechanism directly giving Allyl alcohol in high yield and purity.

Table 1. Non catalytic and homogeneous catalyst systems for the DODH of glycerol

In 2015, Zhang et al. [2] reported the synthesis of acrylic acid from glycerol with a two-step protocol, where allyl alcohol was obtained as a reaction intermediate. Glycerol was mixed with FA, and then heated at 235°C under ambient atmosphere. Allyl alcohol was then collected by condensation. After two hours of reaction under batch conditions, a conversion of 90% was achieved. On the other hand, under steady state of continuous distillation process, a yield in allyl alcohol of 99% was obtained after two hours of reaction at the same temperature. Hence, it was demonstrated that a flow reaction system present a higher productivity. However, this approach is limited by the thermal instability of FA that can decompose to hydrogen and carbon dioxide at high temperatures.

In 2017, Tshibalonza et al. [1] reported the DODH of glycerol toward allyl alcohol in micro fluidic continuous flow reactors (µFRs) mixing glycerol with FA and/or triethyl orthoformate.

Using pure FA, only 56% yield in allyl alcohol was obtained at 315°C after 6 min of reaction.

This moderated yield was related to the formation of water during the DODH reaction, which implies reversible reaction during DODH mechanism. Once the mixture was dried and recirculated to the reactor under the same conditions of the first run, a yield of 70% was obtained. Thereby, a negative influence of the water content in the DODH reaction, was observed, especially in a closed system such as a µFRs. In presence of triethyl orthoformate, DODH of glycerol proceed in a temperature range of 215-315°C, being in agreement with the results reported by Crank et al. [8] , known as Eastwood's olefination, where yields up to 72%

were obtained at 220°C after 4h of reaction in the presence of orthoesters. Nevertheless, Tshibalonza et al. [1] reported only a maximum yield in allyl alcohol of 27% at 250°C. In this case, the authors improved the allyl alcohol performance employing a mixture of FA and triethyl orthoformate (0.1:1). A yield in allyl alcohol of 86% was observed at 250°C after 6 min of reaction.

I.2. Homogeneous catalysts

I.2.1 Initial studies: Rhenium complexes with PPh3, Na2SO3, and glycerol as reductants

Organometallic rhenium derivatives have been widely studied for the DODH of glycerol. In 1996, Cook et al. [9] developed the first DODH catalytic process based on a rhenium complex.

It evidenced the efficiency of Cp*ReO3 for the deoxydehydration of diols into the corresponding olefin in the presence of PPh3 as an oxo-acceptor (reductant). A yield in allyl alcohol of 67% at 125°C and 27h, was achieved. The catalytic performance was regulated by the nature of solvent and the amount of reductant (PPh3). Hence, they reported that coordinating solvents such as THF and N-methyl-pyrrolidinone (NMP) impact the stability of the catalyst.

Similarly, an overreduction of the rhenium complexin excess of PPh3leads to the formation of rhenium (III) complex, which are catalytically inactive on DODH. In 2011, Ahmad et al. [10] reported the use of a cheap and widely available reductant, sodium sulphite (Na2SO3). DODH of glycerol was carried out under neat conditions, giving a yield of 15% in allyl alcohol at 150-160°C after 67h, using sodium perrhenate (NaReO4). In 2012, Abu-Omar et al. [11] showed that MeReO3 (MTO), a water and air tolerant homogeneous catalyst was able to transform glycerol under neat conditions in the presence of a base at 165°C, presenting a yield in the range of 75% of volatile products : allyl alcohol (1)/ acrolein(0.22)/ propanal(0.15), at full conversion. The result was correlated with the initial amount of glycerol. In fact, a maximum of 50% due to glycerol was sacrificed as an internal reductant and eventually oxidized into dihydroxyacetone (one equivalent). In 2013, Raju et al. [12] reported the use of 1,2,4-tri(tert-butyl)cyclopentadienyl ligand in the development of a new catalyst. The 1,2,4-tri(tert-butyl)cyclopentadienyl trioxorhenium complex (Cp ttt *ReO3) presented high catalytic activity (91% in yield) when triphenylphosphine (PPh3) was used as reductant. Overall, authors reported higher conversions and yields using non-polar solvents such as Chlorobenzene.

I.2.2 Rhenium complexes with secondary alcohols as reductants

The use of sacrificial hydrogen donor like alcohols has also been widely studied. Especially, the system formed of MTO and 3-Octanol displayed an excellent yield of 90% at 170°C and 2.5h, reported by Shiramizu et al. [13] in 2012. This work demonstrated that short-chain alcohols (less than 4 carbons) are ineffective H-donors. In contrast, for long chain alcohols ( ≥ 5 C), secondary alcohols were found to be more favourable than primary alcohols. A year later, Boucher-Jacobs et al. [14] developed a DODH catalyst/reductant systems economically more attractive. They studied the use of ammonium perrhenate (APR) as catalyst because of its relatively low cost, greater hydrolytic stability and solubility properties (easier recovery) in comparison to MTO. Despite the good performance of the secondary alcohol such as 3-octanol as reductant (70% in yield), benzyl alcohol, a primary alcohol (47% in yield) was preferred because of the formation of an aldehyde as co-product, which could be separated/recycled easier than the ketones resulting from the secondary alcohols. In 2014, Canale et al. [3] reported an optimal temperature of 140°C for the DODH reaction. They observed that catalysts as Cp*ReO3, Re2(CO)10 and APR were not active in DODH under neat and aerobic conditions.

Indeed, only MTO and rhenium trioxide (ReO3) presented moderated performances (14% and 32%, respectively). A large number of solvents were tested under air and H2 atmosphere such as 2,4-dimethyl-3-pentanol, 1-hexanol, 1,3 propanediol, 2-octanol and 1-phenyl-ethanol.

Among this library of alcohols, 2,4-dimethyl-3-pentanol gave the best results. Yields in allyl alcohol of 87% and 91% were obtained with MTO and ReO3 under H2 atmosphere, respectively.

In 2015, Boucher-Jacobs et al. [15] explored other commercially available reductants in combination with MTO such as 1,2-dihydroacenaphthylene, 9,10-dihydroanthracene, 1,2,3,4tetrahydronaphthalene, indoline, 2,3-dihydro-1H-inden-1-ol, 9H-fluorene and cyclohexa-1,3diene. Hereby, Indoline displayed a good catalytic performance in the conversion of glycerol to allyl alcohol with a yield of 80% after 24h of reaction at 150°C. Despite its use as solvent, it was evidenced that 1-butanol did not compete as reductant since the corresponding aldehyde was weakly detected during reaction. Therefore, this work confirmed that indoline is a better H-donor compared to primary and secondary alcohols. Gebbink et al. [16] carried out a slight change of the ligand Cp ttt reported by Raju et al. [12] , resulting in a more active trioxo-rhenium complex. C tt ReO3 (C tt = 1,3-di-tert-butylcyclopentadienyl) with higher yields in allyl alcohol ( 99% using 3-octanol as reductant). In this work, the catalytic performance of C tt was correlated with its structure i.e. its overall steric bulk compared to C ttt ligand.

I.2.3 Molybdenum and vanadium complexes

Considering the similarities between oxorhenium (VII), oxomolybdenum (VI) and oxovanadium (V) complexes, some studies were focused on the possibility of using these transition metals for the DODH reaction. In 2014, Dethlefsen et al. [17] reported the catalytic activity of Molybdenum, employing a commercial catalyst, (NH4)6Mo7O24 under solvent-free conditions. As presented in Figure 3, the main advantage of the molybdenum-catalyzed approach was the higher volatility of the oxidation products such as glycolaldehyde and formaldehyde (Figure 3-b) preventing wasteful polymerization in the reactor, compared to 1,3dihydroxyacetone reported by Abu-Omar et al. [11] (Figure 3-a). Nevertheless, lower yields in allyl alcohol were obtained with Mo-complex (9%) compared to the Re-complex (27%) [11] . This poor yield was explained by the formation of intermediate acetals which converted the glycerol, and negatively impacted the selectivity towards allyl alcohol.

Figure 3. Comparison of the Re, Mo and V -complexes in DODH of glycerol into Allyl alcohol. [11][17] [18] In 2018, Petersen et al. [18] studied several oxovanadium species such as NaVO3, V2O4, V2O5

V(acac)3 in the DODH of glycerol under neat conditions at 275°C and 4-5 h, in a reactive distillation set-up. Among these complexes, commercial ammonium metavanadate (NH4VO3) displayed the best performance with a yield of 22% using 1% mol. As presented in Figure 3-c, the authors proposed that the mechanism involved the formation of dihydroxyacetone (similar to rhenium complex). However, considering the high temperatures, DHA was subsequently converted to propanal with 1,2-propanediol as intermediate.

I.2.4 Main homogeneous reaction mechanisms in DODH reaction

Depending on the catalyst and the reductant, different reaction mechanisms have been proposed in the literature [7][11][15][19] [20] . Concerning formic acid-assisted DODH of glycerol, the proposed reaction mechanism (Figure 4) proceeds through the formation of a cyclic carbocation intermediate, which subsequently give 2-acyloxy-1,3-dioxolane that finally yields allyl alcohol through a thermal carbon dioxide elimination and hydrogen transfer [7][19] .

In the case of rhenium complexes such as MTO under neat conditions, the reaction mechanism (Figure 5) involves a transfer hydrogenation from glycerol to a rhenium diolate complex (rhenium VII) followed by an alkene extrusion step (rapid) from the resulting rhenium (V) diolate, giving, allyl alcohol. As observed, during the DODH cycle, dihydroxyacetone (DHA)

and water are obtained as by-products. Therefore, active catalytic species of DODH cycle are Re (VII)/Re(V).

When secondary alcohols such as 3-octanol are employed as reducing agent (Figure 6), a similar reaction mechanism was reported. Re (VII)/Re(V) were proposed as active catalytic species. In this case, the secondary alcohol is coordinated to the rhenium VII complex, giving the corresponding ketone and Re(V). The selectivity was correlated with the rate of diol coordination to the Rhenium V complex and/or olefin extrusion [20] .

Figure 4. Reaction mechanism for allyl alcohol formation from glycerol and formic acid [7][19] Figure 5. Reaction mechanism for DODH of glycerol by MTO [11][19] . Figure 6. Reaction mechanism for MTO-catalyzed DODH reaction with a secondary alcohol as H-donor [20]

I.3. Heterogeneous catalytic process

The previous sections covered the homogeneous catalytic process of DODH of glycerol into allyl alcohol, where rhenium was the main approach. Despite the high catalytic performance of these systems, their main drawback is the difficulty to recycle the catalyst [21] . Therefore, heterogeneous catalytic processes are of interest and have recently been subject of research.

Among these studies, rhenium-based catalysts have been the main target of study (Table 2, entries 1-5). Alternative metals such us Fe, Zr, Nb and V, have been part of the discussion (Table 2, entries 6-9).

I.3.1. Rhenium metal as main active phase

In 2016, Palkovits et al. . [22] developed the first stable heterogeneous catalyst (ReOx/TiO2) for the DODH reaction. The corresponding catalyst showed a yield in allyl alcohol of 48-54%, using 3-octanol as reductant. Additionally, ReOx/TiO2 exhibited stability with no deactivation over six runs and no traces of leaching. In the same year, Tomishige et al. [6] reported a higher yield (91%) in allyl alcohol using ReOx -Au/CeO2 catalyst and hydrogen as reductant and 1,4dioxane as solvent. Gold particles were found an effective component to improve the allyl alcohol selectivity. The corresponding catalyst displayed a stability after regeneration by calcination during 4 cycles. In 2017, Kon et al. [23] studied other solid supports for the DODH of glycerol into allyl alcohol, working with alcohols as reductants and solvents. Impregnation of HReO4 on SiO2, TiO2 and Al2O3 was carried out via incipient wetness impregnation method.

Different kinds of alcohols such as 3-Hexanol, 2-Hexanol, 3-Octanol, 2-butanol, 1-Hexanol, 1octanol, 1-butanol, cyclohexanol, benzyl alcohol and 1-Phenylethanol were examined. In general, long-chain secondary aliphatic alcohols gave high yields in allyl alcohols (>84%).

Among these catalysts and reductants, ReOx/Al2O3 in combination with 2-Hexanol achieved the best catalytic performance (91% in yield) at 170°C and 2.5h. The corresponding catalyst could be recycled up to 3 times without considerable loss of the activity after intermediate calcinations.

8

Fe-ZSM5-Rb 340°C Flow 12 [28] 9

Nb-Si-V H2O2 250 4 5.6 [29] Instead of solid supports, Gross et al. [24] investigated the catalytic performance of bimetallic platinum-rhenium nonporous networks (Pt-Re BNN) for DODH of glycerol into allyl alcohol, using 3-octanol as H-donor. The authors reported a bimetallic network composition of 60% Pt (77% Pt 0 and 23%Pt 2+ ) -40% of Re (80% Re 7+ and 20% Re 2+ ), leading to a yield of 47% in allyl alcohol at 160°C, after 12 h under inert atmosphere (N2). However, when the bimetallic network with the composition 90%Pt (77% Pt 0 and 23%Pt 2+ ) -10% of Re (60% Re 2+ and 40%

Re 4+ ), was tested, the yield in allyl alcohol was only 0.05%. These experiments evidenced the catalytic activity to the rhenium content as well as its high degree of oxidation. Moreover, no evidence of leaching was reported by the authors, indicating a high stability of the catalysts.

Later, Abu-Omar et al. [25] synthetized rhenium oxide nanoparticles (ReOx) using 3-octanol as reducing agent at 170°C under aerobic conditions. A yield in allyl alcohol of 76% was obtained after 10 h of reaction. The authors claimed a good catalytic stability after seven runs.

I.3.2. Alternative metals: Fe, Zr, Nb and V.

Other studies have explored metals such as Fe, Zr, Nb and V. In 2014, Tago et al. [26] carried out the catalytic conversion of glycerol into allyl alcohol with iron oxide-based catalysts at 350°C, using a fixed-bed flow reactor. A yield in allyl alcohol of 13.7% was obtained, using ZrO2-FeOx as a catalyst. The impregnation of alkali metals such as potassium (K/ ZrO2-FeOx) allowed an increase of allyl alcohol yield to 27%. The authors proposed that the latter was related to the decrease of acid sites responsible of the dehydration of glycerol into aldehydes and ketones. Stockenhuber et al. [27] carried out the DODH of glycerol over alumina-supported iron catalyst using oxalic acid and FA as sacrificial reductants at 340°C with corresponding yields in allyl alcohols of 17.8% and 19.5%. In 2016, the same authors presented [28] zeolitesupported iron catalysts,. Considering that the acidity is related to acrolein formation, while basicity is believed to promote the selectivity towards allyl alcohol [26][30] [31] , the acidity was mediated via rubidium deposition. Thus, in the case of Fe-ZSM5-Rb (zeolite: Si/Al=30, Iron=13wt %) a yield of 12% in allyl alcohol was observed, while Fe-ZSM5 yielded only 7%.

In 2017, Oliveira et al. [29] reported the catalytic performance of niobium and vanadiummodified silicate (Nb18V4O55) in presence of hydrogen peroxide at 250°C during 4h, employing crude and commercial glycerol. Using crude glycerol, a high glycerol conversion of 97% was obtained, while only 40% of conversion was achieved with commercial glycerol. Likewise, it was proposed that the selectivity to allyl alcohol depended on the glycerol source. Hence, crude glycerol gave mainly acetol and acetone as products (selectivity in allyl alcohol of 4%), while commercial glycerol mainly yielded allyl alcohol (14% of selectivity).

I.3.3. Heterogeneous reaction mechanisms on DODH reaction

In heterogeneous DODH reaction, based on the rhenium active species, two reaction mechanisms have been proposed [6][23][25] [32] . The first one involves the redox pair Re(VII)/Re(V) during DODH reaction. This reaction mechanism considered the relevant findings for Re-catalyzed homogeneous DODH reaction, addressed previously [11][20] . As illustrated in Figure 7, when a heterogeneous catalyst such as ReOx/Al2O3 and a secondary alcohol are used, Re(VII) is reduced by the secondary alcohol to Re(V) accompanied with the formation of the corresponding ketone, with similar mole rate to allyl alcohol (1:1). The asformed Re (V) sites coordinates glycerol to give allyl alcohol, followed by the site reoxidation to Re(VII) [23] . Similar reaction mechanism were evidenced with rhenium oxide nanoparticles and 3-octanol as secondary alcohol, where dioxorhenium (VII) was proposed as active specie and des-oxo-rhenium (V) as olefin extrusion specie [25] .

Figure 7. Reaction mechanism for ReOx/Al2O3-catalyzed 2-hexanol-driven DODH reaction [23] The second mechanism involves the redox pair Re(VI)/Re(IV) during DODH reaction. This redox couple reported by Tomishige et al. [6] was based on the use of ReOx-Au/CeO2 as catalyst and hydrogen as reductant (Figure 8). In this mechanism, the gold particles promote the reduction of Re(VI) species to Re(IV), which play the role of a hydrogen carrier, enabling the dissociation of H2 across the ceria support. Three main steps during each DODH cycle are proposed: electron reduction of Re (VI) to Re (IV), coordination of glycerol as diolate, followed by its reduction to allyl alcohol and finally, reoxidation of the Re-species to Re(VI). A simulation study based on this DODH reaction system was carried out by Heyden et al. [32] .

They asserted that the adsorption of hydrogen on the ceria surface is very exergonic, indicating that the H2 molecule is adsorbed as soon as DODH reaction starts and these atoms migrate to rhenium sites using support vacancies.

Figure 8. Reaction mechanism for ReOx-Au/CeO2-catalyzed H2-driven DODH reaction [6][19] II.

Context of this thesis

Allyl alcohol production from glycerol via deoxydehydration reaction is currently considered a competitive method. As mentioned, the heterogeneous catalytic process is the most interesting approach. According to the literature, the DODH reaction is typically catalysed -with high yields -by rhenium-based catalyst, and requires a stoichiometric reductant such us PPh3, H2 or secondary alcohols. Among these reducing agents, the most promising ones in terms of process competitiveness are the long chain secondary alcohols (C ≥ 5). During the DODH reaction, the alcohol acts as a solvent and hydrogen donor, whereby it becomes oxidized to the corresponding ketone, which could be also a valuable co-product. However, so far, this reaction has been only insufficiently investigated.

A catalyst for the DODH of glycerol to allyl alcohol using 2-hexanol as hydrogen was developed by the UCCS laboratory in 2017 [23] . The main drawback of this catalytic system is the co-produced ketone, namely, 2-Hexanone. This molecule has a high toxicity and no profitable value can be envisaged. Consequently, the alcohol has to be regenerated in order to avoid the ketone accumulation. In this context, in order to approach an economically viable process, an ambitious research project was proposed. The development of an integrated process for allyl alcohol synthesis via deoxydehydration of glycerol using a secondary alcohol as reductant, including the corresponding catalyst development, separation process and modelling.

For this purpose, the research was divided in different tasks: (i) study the DODH reaction in batch mode (ii) the development of the product separation (iii) explore the regeneration of the sacrificial alcohol (2-hexanol) through catalytic hydrogenation of the formed co-produced ketone (2-hexanone), and (iv) design of the continuous process. These tasks are developed and summarized in the three chapters of this manuscript. It should be noted that each chapter is written in article form, as they have already been submitted to scientific journals. The catalyst previously developed by the UCCS laboratory [23] was used as the starting point for the DODH reaction. Rapidly, the recycling protocol for this catalyst was identified as a significant drawback since it included the need of a calcination as intermediate-step for its reactivation.

Correspondingly, the development of a more robust heterogeneous rhenium-based catalyst for the DODH reaction of glycerol to allyl alcohol, is detailed in Chapter 1. Ceria has been in the focus of this study due to the presence of highly reducible Ce 4+/ Ce 3+ species, a high proportion of oxygen surface defects and acid-base properties, making CeO2 a suitable support for the deoxydehydration reaction. Moreover, in order to obtain a mesoporous material, its synthesis was performed via the nanocasting process using SiO2 and activated carbon as hard templates.

Rhenium oxide and 2-hexanol remained as active phase and reductant respectively.

Concerning the development of the product separation, atmospheric distillation was selected as adequate technique, inasmuch as it is a widely applied separation method of liquid mixtures as well as a dominant separation process at industrial scale. Since the latter is based on the vaporliquid equilibrium (VLE), accurate information about the phase equilibria -hitherto unknownis required. Hence, in Chapter 2, the isobaric VLE measurements of the main six binary systems -formed during the DODH reaction -were carried out, for 2-hexanol and MIBC as solvents.

NRTL, UNIQUAC and Wilson thermodynamic models were used for data fitting and thermodynamic consistency was tested verified via Herington, Van Ness, pure component consistency and Redlich-Kister total area test.

The elaboration of a continuous process for the allyl alcohol synthesis from glycerol including integrated product separation, was performed via process modelling using Aspen Plus Software.

In fact, the initial ambition to build a demonstrator of the integrated process, including upscaling, was adapted with respect to the short time frame. Instead, two different scenarios where modelled: the use of 2-Hexanol and MIBC as reductants. Based on the experimental study of the glycerol to allyl alcohol reaction in a batch reactor, the corresponding kinetic parameters were estimated. For the 2-hexanol process, following the principles of green chemistry and carbon economy, a regeneration of 2-hexanol was proposed. The corresponding reaction was studied in laboratory employing a commercial hydrogenation catalyst in order to obtain reliable data for the simulation. On the other hand, for MIBC process, the production and valorisation of MIBK was chosen as an alternative. In this case, experimental data was acquired to study the impact of small amount of MIBK in the DODH reaction. Results of the process simulation are presented in Chapter 3.

Chapter 4 concludes this thesis summarizing the main results obtained and the main perspectives on the upscaling allyl alcohol synthesis. Within this outlook we also present some prospective experimental results obtained for the DODH reaction in continuous flow experiments.

Chapter 1 Catalyst development

Abstract.

The Deoxydehydration (DODH) of glycerol to allyl alcohol was studied over ceriasupported rhenium oxide catalyst. Mesoporous ceria materials were synthetized via a nanocasting process using SiO2 and activated carbon as hard templates. The as-obtained ceria supports were impregnated with ReOx and successfully applied in the DODH reaction of glycerol to allyl alcohol giving excellent yields of up to 86%, using a secondary alcohol as a hydrogen donor and solvent. Since template removal is a critical step in the synthesis of mesostructured ceria, the influence of the presence of the hard template was studied showing no negative effect in the DODH reaction. The corresponding catalyst was reusable for 3 cycles without reactivation step. No evidence of leaching was observed via hot filtration test.

Introduction

Due to the decline of petroleum resources, the utilization of sustainable resources such as biomass has increased and becomes more and more important in the production of chemicals.

With respect to the differences of biomass compared to petrol resources, the main strategy lies in the reduction of the oxygen content to produce diverse classes of value-added chemicals [1][2] [3] . Olefinic compounds are difficult to obtain but are an attractive target since they are important platform chemicals, which today are still mainly obtained from petroleum resources [1][4] [5] . Among those, Allyl alcohol is a promising platform molecule due to its broad range of applications. Its derivatives are present in perfume, pharmaceutical and food formulation. In addition, this molecule is required for the production of allyl diglycol carbonate, 1-3 propanediol, poly (styrene -allyl alcohol), etc., which are used as plasticisers, crosslinking agents, and coating additives [4][6] . Several renewable sources can be envisaged as starting material for the synthesis of allyl alcohol whereby the most promising onenotably in terms of carbon economyis glycerol. Glycerol is the by-product formed during the transesterification of vegetable oils for the production of biodiesel. The increase of this industry, makes glycerol widely available. However, only a few studies on glycerol conversion to allyl alcohol with a cheap reductant have been reported [4][7] . Deoxydehydration reaction (DODH) seems currently the most competitive method, which -to date -has been only marginally investigated. DODH reaction can remove two adjacent hydroxyl groups from vicinal diols yielding the corresponding alkene (Figure 1.1), for example, allyl alcohol in the case of glycerol [7][8] . This reaction is typically catalyzed by rhenium based catalyst and requires a stoichiometric reductant such as H2 or a secondary alcohol [9] .

Figure 1.1. Rhenium-catalyzed deoxydehydration of vicinal diol into an alkene in the presence of a reductant (referred as "red"), R 1 and R 2 = alkyl, aryl, or H [10] .

Few studies have been reported in the literature about the DODH of glycerol to allyl alcohol in liquid phase, which typically uses Rhenium catalysts and enables one-step transformation of vicinal hydroxyl groups into C=C bond. Notably homogeneous catalysts with various reductants for DODH have been reported. An early work from Cook et al. [11] demonstrated the efficiency of Cp*ReO3 for the deoxydehydration of diols into the corresponding olefin in the presence of PPh3 as an oxo-acceptor (reductant). Afterwards in 2012, Abu-Omar et al. [12] showed that MeReO3 (MTO), a water and air tolerant homogeneous catalyst, was able to transform neat glycerol in the presence of a base at 165°C with yields in the range of 75% of volatile products (mainly allyl alcohol) at full conversion. Glycerol was shown to be the hydrogen source and the reaction produced therefore one equivalent of dihydroxyacetone (DHA). Subsequently, the use of sacrificial hydrogen donors like alcohols was also studied. In general, it was found that secondary alcohols improve the selectivity to allyl alcohol compared to the other two volatile products: acrolein and propane, whereby the system formed of MTO and 3-octanol gave an excellent yield of 90% [13] . However, the use of a homogeneous catalyst involves high costs associated with separating the catalyst from reaction mixture [14] .

The application of heterogeneous catalysts is particularly useful from the industrial point of view. They can be proceed with high efficiency, can be regenerated and reused for several catalytic cycles [15] . ReOx/ TiO2 was reported as the first stable heterogeneous catalyst for the DODH. However, there is room for improvement in the catalytic performance since only 58% yield in allyl alcohol from glycerol using 3-octanol as H-donor were reported [16] . After that, an heterogeneous rhenium catalyst for the synthesis of allyl alcohol from glycerol was developed by Kon et al. [17] ; a maximum yield of 91% using 2-hexanol at 148°C was obtained using 10 wt.% ReOx rhenium oxide supported on alumina. This catalyst showed reusability during three cycles, nevertheless, it required an intermediate calcination stage to be reactivated. Recently, Tazawa et al. [4] showed that Au particles can be used as promoters, and that ceria (CeO2) has potential as support for DODH catalysts. They used a ReOx-Au/CeO2 catalyst to efficiently convert glycerol to allyl alcohol using H2 as reductant, obtaining a yield of 91% after 52h of reaction time.

Ceria is widely used for oxygen storage capacity and unique redox properties. The presence of highly reducible Ce 4+ and Ce 3+ species, a high proportion of oxygen surface defects and acid-base properties make CeO2 suitable for catalytic applications [18][19] . Nevertheless, the synthesis of well dispersed ceria or even mesoporous ceria is a challenging issue, there are few reports for the direct and template-free synthesis of CeO2 with mesostructures of narrow pore distributions, rigid frameworks, and well-defined morphologies. One of the ways to stabilize ceria consists in depositing ceria on the surface of a stable matrix, such as silica and then remove the latter using NaOH or HF [20][21] . The hard templates have shown many advantages over soft ones, especially for obtaining highly crystalline walls, well-ordered structure and high surface areas [18] . However, structural transformation during the removal of silica template could damage the ceria properties [22][23] , and therefore, impacts the catalytic performance. Herein, mesoporous ceria materials were synthetized via a nanocasting process using SiO2 and activated carbon as hard templates. The as-obtained ceria supports were impregnated with rhenium oxide (ReOx) and applied in the DODH reaction of glycerol to allyl alcohol, using a secondary alcohol as a hydrogen donor and solvent. 20 g Pluronic P123 triblock copolymer (EO20PO70EO20) were added to 250 g of distilled water.

Experimental methods

The mixture was stirred for 2h at room temperature. After that, 42.6 g of tetraethyl orthosilicate (TEOS, 98 wt. %, Aldrich), 142.8 g of concentrated HCL (35 wt. %) and 275g of distilled water were added and stirred for 1h at room temperature. The mixture was heated under stirring for 20h at 80°C. Finally, the white solids were recovered by filtration, washed with deionised water and dried at 70°C during 24h in an oven. Thereafter, the products were calcined in static air at 550°C for 8h at a heating rate of 1°C/min.

Support CeO2 using SBA-15 as hard template

For the synthesis of the mesoporous CeO2, 2 g of SBA-15 were dispersed in 10 g of Ce (NO3)3*6H2O (99 wt.%, Aldrich) and dissolved in 40 mL of ethanol. The mixture was stirred at 60°C until solvent evaporation. Thereafter, the mixture was calcined to 450°C for 4h (1°C/min). After that, a second impregnation was carried out using 4.8 g of Ce (NO3)3*6H2O in 40 mL of ethanol. Following the solvent evaporation at 60°C, the product was calcined in static air at 600°C for 4h (1°C/min). The siliceous template was later on eliminated in 100 mL of a 2M NaOH solution at 25°C under stirring. The remaining material (mesoporous CeO2) was centrifuged, washed with distilled water and dried at 80°C.

Support CeO2 using Activated Charcoal as hard template

2 g of Activated charcoal were dispersed in 10 g of Ce (NO3)3*6H2O (99%, Aldrich) and dissolved in 40 mL of ethanol. The mixture was stirred at 25°C until solvent evaporation.

Thereafter, the mixture was dried in static air to 200°C for 4h (1°C/min). After that, a second impregnation was carried out using 4.8 g of Ce (NO3)3*6H2O in 40 mL of ethanol. Following solvent evaporation at 25°C, the product was dried in static air at 200°C for 4h (1°C/min) and then, calcined at 460°C for 2h (1°C/min). Activated charcoal template was removed during calcination.

Catalyst preparation

Catalysts with different rhenium contents were prepared by an incipient-wetness impregnation method. Before each synthesis, 2 g of support was washed with distilled water, using vacuum filtration, dried at 110°C (12h) and then calcined under static air at 500°C (3h).

For the preparation of 10 wt.% ReOx, a diluted aqueous solution of HReO4 was added to the support, which was obtained by the mixing 400mg of the 75 wt.% HReO4 aqueous solution with water (0.75 mL). The impregnated catalyst was dried at 110 °C for 12 h and calcined under static air at 500 °C for 3 h using a heating rate of 5°C/min. Concerning the preparation of 2.5 wt.%, 5 wt.% and 15 wt.% ReOx supported catalysts, the synthesis proceeded as 10 wt.% ReOx but using 92, 190 and 635 mg of 75 wt% HReO4 aqueous solution, respectively.

Experimental procedure for DODH reaction of glycerol

Catalytic test for DODH reactions were performed in a pressure resistant glass tube equipped with a magnetic stirring bar charged with glycerol (92 mg, 1 mmol, purity in water >99 wt. %), 100 mg of catalyst, and 3.3 mL of solvent. The vessel was tightly sealed by a screw cap and the mixture was stirred (1300 rpm) in an oil bath maintained at 175 ˚C for 2.5 h so that the reaction medium was maintained at a reaction temperature of 145°C. After the reaction, the solution was cooled to room temperature and placed under ultrasonic irradiation for 5 min at 40 °C to ensure a good homogeneity. Conversion and yield were determined by gas chromatography, using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID).

Catalyst characterization

In order to determine physical properties and bulk properties, the catalyst characterization was carried out using nitrogen adsorption/desorption, Transmission Electron Microscopy (TEM), X-ray Photoelectron Spectroscopy (XPS) and X-ray fluorescence (XRF) and X-ray diffraction (XRD).

Nitrogen adsorption/desorption:

The surface areas, pore volumes and distributions of the pore sizes were determined by nitrogen adsorption/desorption at 77.35 K using a TriStar II Plus and a 3Flex apparatus from Micromeritics. Preliminary degassing of the samples was done at 75°C and 130 °C for 90 min and 17h 30 min, respectively. The specific surface area (BET) was evaluated using the BET method (Brunauer, Emmet and Teller). In addition, the pore size distribution and the pore volume were calculated according to the Barrett-Joyner-Halenda (BJH) formula taking into account the desorption.

Transmission Electron Microscopy (TEM)

Selected catalysts were characterized by TEM to obtain local information at the nanometric and atomic levels on the morphology, structure, chemical composition, size and distribution of the nanoparticles on the support. The transmission electron microscope used was a FEI Tecnai G2 20 (TEM) equipped with an EDX (Energy-dispersive X-ray spectroscopy) micro-analysis, a

Gatan energy filter (EELS), precession and electron tomography systems and an ORIUS CCD camera. This microscope uses a voltage of 200 kV for the acceleration of electrons. Sample preparation was done by inserting the support mesh into the catalytic converter in order to adhere the powder grains.

X-ray Photoelectron Spectroscopy (XPS)

XPS analyses were performed on a high-performance hemispheric analyzer VG Escalab 220 XL spectrometer and on a XPS KRATOS, AXIS UltraDLD with monochromatic Al Kα (hν = 1486.6 eV) radiation as the excitation source. The survey spectra (160 eV) and the high resolution spectra (20 eV) of the Re 4f, C 1s and O1s were collected. Binding energies were calibrated by setting the C 1s peak to 284.8 eV.

X-ray fluorescence spectroscopy (XRF)

XRF was used for studying the elemental composition of different materials. In the present work, relative content of all species was determined with the use of an energy dispersive micro-X-Ray Fluorescence spectrometer M4 TORNADO (Bruker). The Rhodium X-ray anode was used 50 kV/600 mA (30 W). This X-rays Rhodium is equipped with a polycapillary lens enabling excitation of an area of 200 μm. The detector used was a Silicon-Drift-Detector Si (Li) with <145 eV resolution at 100000 cps (Mn Kα) and cooled with a Peltier cooling (253°K). The measurement was done under vacuum (20 mbar). Quantitative analysis was done using fundamental parameter (FP) (standardless). To obtain accurate quantification of the components present in the catalysts, each sample was irradiated 35 times in order to obtain accurate mean values.

X-ray diffraction (XRD)

XRD was used to determine the crystal structure on a D8 Discover X-Ray Diffractometer from Bruker using a X-Ray tube in Cu (Kα) radiation (λ=1.54060 Å). The diffraction angle 2θ was in the 10-70° range with steps of 0.01° per second. The interpretation of the XRD patters obtained was done from Diffract Eva software and the identification of the crystalline phase was done from reference standards.

Temperature-programmed reduction (TPR)

TPR analysis were performed on an automated AutoChem II 2920 Chemisorption Analyzer from Micromeritics. At first, 50 mg of catalyst were weighted and inserted into a glass reactor.

Then, the sample was flushed with a mixture gas of 5 vol.% H2 in Ar at room temperature.

While the gas was flowing, the temperature of the sample was increased linearly at a ramp rate of 10°C/min up to 1000°C. Finally, the consumption of hydrogen by adsorption/reaction was monitored to obtain quantitative information on the reducibility of the species present in the catalyst.

Results and discussion

Catalyst characterization of ceria-supported rhenium oxide catalyst

Textural characteristic and elemental composition of samples

The textural characteristic of the samples are summarized in Table 1.1. For all the catalysts, the specific surface area and the pore volume were lower in comparison with the parent support. The latter can be explained by the filling of the pores of the support by the rhenium active phase leading to a decrease of the overall pore volume. On the other hand, the mean pore size of the catalysts was generally close to the one of the parent support.

The comparison of the textural properties of CeO2+SiO2 and CeO2+SBA-15 supports (Table 1.1, entry 5 and 11, entry 13 and 15, respectively) before and after treatment with NaOH, showed an increased specific surface in case of CeO2+SiO2 after NaOH treatment (from 87.8 to 113.6 m 2 g -1 ) which was not observed in the case of CeO2+SBA-15 (from 119.6 to 100.9 m 2 g - 1 ). However, both showed an increased total pore volume after NaOH treatment (0.4 and 0.5 cm 3 g -1 , respectively). The latter can be explained by the partial removing of the hard template from the corresponding support, as evidences by XRF (next paragraph). In the case of total removing of carbon as hard template (Table 1.1, entry 17 and 18), a change in the textural properties was observed, specific surface increased from 60,37 to 66,44 m 2 g -1 and total pore volume from 0,06 to 0,08 cm 3 g -1 . In contrast, the textural properties of CeO2 (HSA-5) (Table 1.1, entry 1 -3) were not modified after NaOH treatment.

The amounts of rhenium and silica in the synthesized catalyst and supports were determined by X-ray fluorescence (XRF) and are presented in Table 1.1. Concerning the amount of Re, one can see, the theoretical and actual loadings of the active phase were always lower for all catalysts. This might be due to the high volatility of Rhenium oxide, mainly Re +7 species [24][25] ,

resulting in some loss of Re during calcination. With respect to the leaching of the active phase, it was stated that the Re amount did not change upon multiple uses (from 7.8 to 7.4 wt.%) [16] .

In addition, according to the XRF analysis shown in Figure 1.S1, after the matrix removal procedure, no trace of sodium was identified on the surface of the catalysts 10 wt.% ReOx/CeO2+SiO2 and 10 wt.% ReOx/CeO2+SBA-15. Comparing the silica composition of this last catalysts (Table 1.1, entry 8 and 12, entry 14 and 16, respectively), the removal of SBA-15 was higher than for SiO2 (81% and 57%, respectively). However, a complete hard template removal was not observed.

X-ray diffraction and TEM

As shown in Figure 1.2 and Figure 1.S2, for all catalysts, only the ceria phase [26] [27][28] [29] can be detected by XRD for the corresponding catalyst. The characteristic peaks are very close to the fluorite structure of CeO2 (space group Fm3m) reported in JCPDS card (No. 81-0792). The characteristic peaks corresponding to the (111), ( 200), ( 220), (311), ( 222), (400) crystal planes are located at 2θ = 29.2°, 33.1°, 47.5° , 57.6°, 59.0°, 69.4°, respectively. No diffraction patterns related to Rhenium oxide were detected by XRD, indicating its good dispersion on the surface of ceria support when using low amount of Rhenium (≤ 10 wt.%). However, characteristic peaks corresponding to Re2O7 crystals were detected on 15 wt.% ReOx/CeO2+SiO2, indicating a possible Rhenium crystal growth [30] [31] [32] . These results were confirmed by TEM. The image analysis allowed to establish the particle size distribution, confirming the agglomeration of rhenium species in the case of 15 wt.% as Re loading (Figure 1.3) with a maximum particle size of 10 nm, contrary to 10 wt.% Re, where the maximum particle size is around 3nm. In Figure binding energy (BE) were ascribed to Re 4f7/2 and correspond to Re 7+ (84.09%) and Re 6+ (15.91%), respectively [24][33] [34] [35] . In the case of the spent catalyst, the peaks shifted to lower BE.

The peaks at 46.0, 44.7, 43.7, and 42.7 eV were assigned to Re 7+ (39%), Re 6+ (33%) and Re 5+ (22.3%) , Re 4+ (5.65%), respectively [24][33] [34] [35] . These results are consistent with the formation of partially reduced ReOX species during the reaction. Tomishige et al. [START_REF] Hayasaka | Deoxydehydration of Glycerol to Allyl Alcohol over ReO x -Au / CeO 2 catalyst with[END_REF] prepared ReOx-Au/CeO2 for heterogeneous DODH under hydrogen and proposed a redox cycle with Re 6+ /Re 4+ .

On the other hand, Jun Hee Jang et al. [33] found high catalytic activity of Re 7+ /Re 5+ species before and after reaction using Re nanoparticles and 3-Octanol as reductant. However, in our study, both Re 5+ and Re 4+ where found after reaction, suggesting that both redox couples Re 7+ /Re 5+ and Re 6+ /Re 4+ are involved.

With respect to the differences in the studies (supported and non-supported Re), it seems possible that the supportnamely ceriaprevents the deep reduction of Rhenium (<Re IV ). In order to see if ceria was contributing as a redox couple in the DODH reaction, the Ce3d peaks of the fresh and spent catalyst were studied (Figure 1.5). The peaks at 898.8, 890.16 and 882.9

eV binding energy (BE) were ascribed to Ce3d5/2 , corresponding to Ce 4+ species and the peaks at 887.19 and 882.0 eV correspond to Ce 3+ species [26] . The fitting of the peaks showed that the Ce 3+ /Ce 4+ ratio before and after reaction was 0.28 and 0.27, respectively. Thus, no significant changes on the redox cycle of the ceria support were observed during reaction. With respect to the results from literature, it is noteworthy that Ota et al. [4][30] , observed a deep-reduction of Rhenium until Re 0 , under reaction conditions over ReOx-Pd/SiO2 which they related to the deactivation of the catalyst. Also, they claimed a decrease of the catalytic activity in DODH reaction using pre-reduced ReOx-Pd/CeO2 catalyst without exposure to air in comparison with non-reduced catalyst, probably caused by reduction of Ce 4+ to Ce 3+ . Within this glance, the influence of the NaOH treatment on the oxidation states was analyzed (Table 1.2, entries 2, 5 and 7). In these cases, an increase in the Re 6+ /Re 7+ and Ce 3+ / Ce 4+ ratio was observed.

Considering that reduction of Re is involved in the catalytic cycle of DODH (Figure 1.5 and (a) Fresh catalyst, After NaOH treatment (b) Used catalyst, Without NaOH treatment

Temperature-programmed reduction (TPR) analyses

The temperature-programmed reduction (TPR) profiles of 10 wt.% ReOx/CeO2 (HSA-5) and support CeO2 (HSA-5) are shown in Figure 1.6. Both profiles have a broad signal above 900 K with almost identical surface integration, attributed to the oxygen species in bulk CeO2.

In the case of pure CeO2 (a), the low temperature peak from 550 -850K is ascribed to the reduction of the most easily reducible surface-capping oxygen on CeO2 [27][37] [START_REF] De Souza E Silva | Synthesis and structural characterization of nanometric ceria highly dispersed in SBA-15 with oxygen exchange capacity[END_REF] . Moreover, the overall consumption of hydrogen in the TPR of pure ceria is 1541 µmol/g, corresponding to an average Ce reduction of 53%. When 10 wt.% of Rhenium oxide was supported on ceria, the TPR pattern showed a sharp peak at 760 K [30] with a total H2 consumption in the range of 600 -850K of 1930 µmolH2/g. This value was significantly larger (H2/Re = 9.3) than for the total reduction of Re (H2/Re = 3.5) due to the fact that some Ce species were reduced simultaneously in this temperature range. Hence, the redox cycle of Ce could be related to the reduction of rhenium species, confirming the XPS results.

Deoxydehydration (DODH) of glycerol

The influence of the preparation of CeO2 using different hard-templates on the catalytic performance was studied (Table 1.3). Similar yield in allyl alcohol was obtained using commercial CeO2 (HSA-5), CeO2+SiO2 and CeO2+SBA-15 as supports, with 84, 86 and 88%, respectively. The catalyst prepared using activated charcoal as hard template (Table 1.3, entry 7) showed a slightly lower yield in allyl alcohol of 80%. It is noteworthy that the BET surface area and the type of silica matrix were not related to the yields (Table 1.1, entries 2, 8,

Furthermore, the results also showed that the remaining silica had no effect on the catalytic performance in the DODH reaction. In contrast, when traditional removal of silica with NaOH (2M) was carried out in commercial CeO2 (HSA-5), CeO2+SiO2 and CeO2+SBA-15, a decrease in yield of around 14% was obtained (Table 1.3, entry 2, 4 and 6). As aforementioned, after the matrix removal procedure, no trace of sodium was identified on the surface of catalysts, therefore, the impact on the catalytic performance of DODH reaction could be possibly due to changes in redox properties of the support, observed by the increase in Ce 3+ / Ce 4+ ratio (Table 1.2) [START_REF] Zhang | Shape-controlled synthesis and catalytic application of ceria nanomaterials[END_REF] . The influence of the ReOx amount was studied using the CeO2+SiO2 support with 2.5 wt.%, 5

wt.%, 10 wt.% and 15 wt.%. The corresponding results and reaction conditions are shown in Table 1.4. The support did not show any catalytic activity toward allyl alcohol production (entry 1). Glycerol conversion increased as the amount of rhenium oxide increased (entries 2-5). Since a good distribution of the active phase was observed when 2.5, 5 and 10 wt.% of rhenium were impregnated (entries 2-4), similar selectivity was observed (around 85%). The conversion increased with the amount of active phase whereby complete conversion was obtained for 5 and 10 wt.%; 2.5 wt.% shows still fair activity with a conversion of 90% (entry 2). When 15 wt.% of rhenium was used, a decreased selectivity of 81% was observed, which could be explained by the clustering of rhenium active sites (entry 5), as previously stated for a ReOx/Al2O3 catalyst by Kon et al. [17] . Considering that 10 wt.% ReOx / CeO2+SiO2 is the catalysts giving highest yield (86%), this catalyst was used in the following tests for recyclability. Regarding the possible scale-up to a continuous process, the reuse of the 10 wt.% ReOx/ CeO2+SiO2 catalyst was studied. The DODH of glycerol was carried out at 175°C, 1300 rpm and 2h. Between each cycle, the catalyst was only washed with the reaction solvent, in order to avoid glycerol and allyl alcohol accumulation as adsorbed species. The relative amount of glycerol to the quantity of recovered catalyst from the previous run was kept constant. As one can see from the results, the corresponding catalyst did not lose any activity with reuse: yield remains stable at around 58% after three cycles (Figure 1.7). This result also indicates that the active catalyst was not a homogeneous rhenium complex resulting from the dissolution of the rhenium oxide supported on ceria. This was subsequently validated by a hot filtration test, where the catalyst was filtered off after 1h of reaction, and the filtrate showed no further increase in allyl alcohol during 24h of reaction (Figure 1.8). long-chain aliphatic secondary alcohols, such as 2-hexanol, 4-methyl-2-pentanol (MIBC), 3octanol and 2-pentanol (86%, 85%, 79%, and 65%, respectively) (Table 1.5, entries 1-4). In contrast, the performance of primary alcohols such as 1-heptanol (Table 1.5, entry 5) and shortchain aliphatic secondary alcohols, such as 2-butanol (Table 1.5, Entry 6), gave a yield in allyl alcohol of 22% and 24%, respectively. Cyclic alcohol (cyclohexanol) showed a moderated yield of 21%. In general, in accordance with the literature [17][9] [1] , aliphatic secondary alcohols having longer chains are more suitable H-donors for DODH of glycerol.

Entry Catalyst Conversion (%) (b) Yield (%) (b)

Conclusion

The Deoxydehydration (DODH) of glycerol to allyl alcohol was studied over ceria-supported rhenium oxide catalyst. SiO2 and Carbon were used as hard templates in the synthesis of mesoporous ceria materials, via nanocasting process. Ceria-supported rhenium oxide catalyst was successfully applied giving excellent yields of up to 86%, using a secondary alcohol as a hydrogen donor and solvent such as 2-hexanol and 4-methyl-2-pentanol. The corresponding catalyst was reusable for 3 cycles without reactivation step. No evidence of leaching was observed via hot filtration test, confirming the heterogeneous nature of the catalytic reaction.

The presence of a silica matrix showed no negative effect in the DODH reaction. In contrast, a partial removal of silica matrix -81% for SBA-15 and 57% for SiO2 -by NaOH treatment, resulted in a decrease in the allyl alcohol yield of around 14%. Since no influence of the textural properties on the catalytic performance was found, the observed decrease in the catalytic performance upon hard-template removal was ascribed to the change in redox properties of the support, leading to an increased Ce 3+ /Ce 4+ ratio in all treated catalysts. Additionally, this study showed that both redox couples Re 7+ /Re 5+ and Re 6+ /Re 4+ are involved during DODH of glycerol to allyl alcohol. and vapor mole fraction (yi) were less than 0.24 and 0.0089, respectively, which indicate that this three thermodynamic models can be used to correlate the six binary systems and therefore they can be employed for the development and optimization of the separation process.

Supporting information

Introduction

The Deoxydehydration (DODH) of glycerol is an alternative and sustainable reaction, for the synthesis of allyl alcohol which has recently gained much attention [1] [2][3] [4] . Generally, a DODH reaction removes two adjacent hydroxyl groups from vicinal diols to afford the corresponding alkene, in the current case, allyl alcohol from glycerol [5][6] . This reaction is typically catalyzed by rhenium based catalyst and requires a stoichiometric reductant such as H2 or a secondary alcohol [7] . The reductant-solvent acts as hydrogen donor and become oxidized to the corresponding ketone and water is also produce. Considering the application of allyl alcohol as a monomer in the chemical industry, it is imperative to isolate it in high purity from the reaction mixture containing the solvent, the co-produced ketone and water. Hence, in order to develop separation and purification strategies for allyl alcohol from the DODH of glycerol, high precision experimental phase equilibrium data are required [8][9] .

The Vapor-liquid equilibrium of allyl alcohol/water is already reported in the literature [10] and vapor-liquid-liquid equilibrium of solvent/water and ketone/water binary systems are in Aspen database. Thus, this work focuses on the experimental measuring of VLE data for the binary mixtures of Allyl alcohol/2-hexanol, Allyl alcohol/2-hexanone, 2hexanone/2-hexanol, Allyl alcohol/MIBC, Allyl alcohol/MIBK, and MIBK/MIBC at 101.32 kPa, in order to calculate the adjustable binary interaction parameters from local-composition models [11] . In order to validate the accuracy and quality of the VLE data, the Herington [12][13] ,

Van Ness [14] pure component consistency [15] and Redlich-Kister [16] total area tests were implemented to verify the thermodynamic consistency of VLE data sets before fitting using the universal quasichemical (UNIQUAC) [17] , non-random two-liquid (NRTL) [18] and Wilson [19] thermodynamic models.

Experimental section 2.2.1. Materials

All of the experimental chemicals used in this study are listed in Sigma-Aldrich ≥ 0,990 369.98 369.75 [10] 370.07 [20] 369.94 [21] GC b

2-hexanol

626-93-7

Sigma-Aldrich ≥0,990 412.77 413.04 [22][23] GC b

2-hexanone

591-78-6

Acros

Organics ≥0,980 400.12 400.7 [23] GC b

4-methyl-2-pentanol (MIBC)

108-11-2

Sigma-Aldrich ≥ 0,980 404.75 404.85 [23] GC b

4-methyl-2-pentanone (MIBK)

108-10-1

Sigma-Aldrich ≥ 0.995 388.83 389 [23] GC b a The experimental pressure for the measurement of boiling temperature is 101.32 kPa; standard uncertainties of experimental pressure and temperature are u(Tb) = 0.1K u(P) = 0.1 kPa. b Gas chromatography.

VLE apparatus and procedure

The binary VLE data were determined using an equilibrium apparatus Fischer VLE 602 equipped with a Cottrell circulation pump (Figure 2.1). Accuracy in measurements of temperature and pressure are ±0.1 K and 0.1 kPa, respectively. The operation procedure is based on the principle of circulation method, to ensure an intimate contact between liquid and vapor phases during the boiling process. At the beginning, the mixed chamber (5) and the side reservoir (1) are loaded with the less volatile pure component, then, different binary mixtures were prepared as needed by controlled addition of the second component to the equilibrium chamber via liquid-phase septum (11). For each equilibrium point, the pressure was fixed and the heating and stirring systems were turned on. The heating supply is adapted so that the reflux flow of the vapor phase is 1-2 drops per second. The apparatus was operated at constant pressure

Sample Analysis

The concentrations of Liquid and condensed vapor samples were determined by gas chromatography using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID). The initial oven temperature was programmed at 40°C for 2 min, with a heating ramp of 10°C/min, up to 100°C. The injection port temperature was maintained at 250°C using split injection mode adjusted to 140:1 ratio. In each analysis, 1µL of sample was injected. VLE samples of 20 µL were diluted in 980 µL of Tetrahydrofuran (THF). 20 µL of benzene was added in each sample as internal standard. The uncertainty in the concentration measurements was determined by analyzing solutions with known composition, using the calibration curves of the chromatographic technique to this end. Ten calibration standards were prepared gravimetrically per each binary system. A maximum standard uncertainty of ± 0.001 in the mole fraction of each component was estimated.

Results and discussion

Vapor pressure correlation of pure components

Despite the availability of vapor pressure data for Allyl alcohol, 2-hexanol, 2-hexanone, MIBC and MIBK in Aspen physical properties database, measurement of the vapor pressure for this components was performed, bearing in mind that this information is fundamental for a proper application of the consistency tests [26] as well as checking the reliability of the equilibrium apparatus used in this work. The experimental vapor pressures of the components are present in

Vapor-liquid equilibrium (VLE) model

VLE experimental data for the binary systems were used to calculate the activity coefficients (𝛾 𝑖 ). The VLE relationship at moderate pressure can be expressed as showed in Eq 2.2 [27] . Due to the fact that the experimental data was obtained at low pressure (101.32 kPa), vapor phase behaviour was considered as ideal gas, and therefore, fugacity coefficient (𝜑 𝑖 𝑣 ) and pointing factor were fitted to one [28] . Thus, VLE expression can be simplified as showed in Eq 2.3.

Where xi and yi are the composition of the liquid and vapor phases, respectively, P is the total system pressure. 𝑃 𝑖 𝑠 is the vapor pressure of pure component i at the system temperature. 𝑃 𝑖 𝑠 was calculated using the Antoine coefficients previously fitted with our experimental data.

Experimental VLE data with the corresponding experimental activity coefficients are listed in To evaluate the ideality deviations of the systems under the same composition and pressure conditions, excess Gibbs energy (G E ) was determined by Eq 2.4 [9] , where R is the universal gas constant, and T is the system temperature. Taking into account that 𝛾 1 and 𝐺 𝐸 values are above unity and zero (

Thermodynamic consistency test

Thermodynamic consistency tests allow the assessment of experimental VLE data on the basis of Gibbs-Duhem equation ( Eq 2.5and Eq 2.6) [15] [26] . The use of several consistency tests is always recommended to check -in the proper manner -the quality of the data, given that, contradictory consistency results can inform one about an incorrect application of a particular test [26] . In this work, Redlich-Kister total area test, Herington test, Modified Redlich-Kister total area test (1948) assumed the volume and heat effects of mixing (ε) are negligible [13] (Eq 2.7 and Eq 2.8 ). According with Kang et al. [15] , a polynomial relation with the form presented in Eq 2.9, with n , between 4 and 6, can be used for regressing data 𝐿𝑛 (

𝛾 1 𝛾 2
).

Nevertheless, due to the absence at the infinite dilution zones, as reported by Duran et al. [8] ,

Margules Activity Model was used in the pure components zones. The corresponding parameters A12 and A21, were obtained by the data regression of Excess Gibbs energy of a binary system [29] (Eq 2.10), the values were summarized in Table 2.7. According with Kojima et al. [16] ,

for |A*|< 0.03, the test is passed. In addition, the tool for thermodynamic consistency available in Aspen Plus V9 was used [30] . This latter is quite similar to Redlich-Kister area test [8][16] [30] . As reported Kurihara et al. [31] , ε for isobaric systems can be large (as high as 0.04) and neglect it, is not recommended. Herington proposed an semi-empirical approach of this term by use of the total boiling range of the mixture [12] (Eq 2.11and Eq 2.12), where γ 1 and γ 2 are the activity coefficients which were calculated by Eq 2. Wisniak [13] slightly modified the Herington criteria; ∆𝐻 𝑚 data were correlated against ∆𝐺 𝑚 𝐸 from experimental data with good results using the Eq 2.13. In this work, the data was calculated from experiments, using Eq 2.3 -2.4 and plotted in Figure 2.3. Each data set was correlated by a sixth order polynomial equation and the maximum value of excess free energy of mixing (∆G 𝑚 𝐸 ) was calculated by derivation. The Van Ness method [14] is a suitable method for testing the sensitive to the selected model as well the reliability of VLE values, thought the mean absolute deviation between experimental data and calculated values by a given thermodynamic model [28] . It is defined by Eq 2. 14 According with the obtained results given in Table 2.8, all binaries were found consistent with the Redlich Kister area test (|A*|<0.03), Aspen plus tool, Modified Herington test (|𝐷 -𝐽| < 10) and Van Ness method (Δy < 1) and ΔT< 1). Despite the fact that the Herington test has been successfully implemented in similar systems containing non-polar compound and alcohols [13][32] [33] [34] , in this study, from 6 data sets, only 2-hexanone (1)/2-hexanol (2) binary was found consistent |𝐷 -𝐽| = 0.99. According to the literature, some researchers have also shown data sets that failed Herington test but passed Redlich-Kister area test [8][35] [START_REF] Hayasaka | Deoxydehydration of Glycerol to Allyl Alcohol over ReO x -Au / CeO 2 catalyst with[END_REF] . In our case, this failure in the Herington test, has been also corrected by leaving out value of ∆𝐻 𝑚 ∆𝐺 𝑚 𝐸 ⁄ = 3

𝐴 * = ∫ 𝑙𝑛 𝛾 1 𝛾 2 𝑑𝑥 + ∫ 𝜀 𝑑𝑥
(Wisniak criterion Eq. 2.13).

Additionally to the requirements associated to the Gibbs-Duhem equation, consistency between the end-points of VLE data sets (i.e., mole fraction of 0 and 1) and the vapor pressures of pure components must be applied [15] . The pure component consistency test is presented in Eq 2.16

and Eq 2.17. Where 𝑝 1 0 and 𝑝 2 0 are the pure component vapor pressures, 𝑃 𝑏𝑢𝑏𝑏𝑙𝑒 is the bubble point pressure. Consistency test is passed if ∆𝑃 1 0 and ∆𝑃 2 0 are less than 1. As presented in Table 2.9, all the experimental data sets pass this criterion.

VLE data correlation

The measured data for all binary systems were correlated by three thermodynamic models, UNIQUAC, NRTL and Wilson, using Aspen plus V11 regression tool. The corresponding interaction parameters were obtained by minimizing the maximum likelihood objective function (OF), defined by Eq 2.18. This OF consist on the sum of differences of measured and predicted variables [11] , where P and T are the equilibrium pressure and temperature, respectively; xi and yi the liquid and vapor mole fraction, respectively; N and 𝜎 are the number of data point and the standard deviation, respectively. According to Renon and Prausnitz [18] , the non-randomness parameter (𝛼 𝑖𝑗 ) was set at 0. To evaluate the difference between the experimental data and the calculated results, the rootmean-square deviation (RMSD) of equilibrium temperature and composition was calculated, according to Eq 2.19-2.20, respectively. The corresponding binary coefficients of the three thermodynamic models for the six systems and those of RMSD are given in The quality of regression could be also confirmed through the correlation of experimental and calculated activity coefficients at 101.32 kPa, since these last coefficients are determined on the basis of all parameters involves in the objective function (Eq 2.18). The experimental data and regression results obtained by UNIQUAC, NRTL and Wilson, for all binary systems are shown in Figure 2.4 to 2.6. As shown, Txy diagrams have been adjusted successfully in all composition range unlike experimental activity coefficients in the infinite dilution zones. The latter is caused by high uncertainties in the GC characterization at high (>0.9) and low (<0.1) mole fractions [26] .

Ln  , Ln  G E /RTx 1 x 2 x 1
UNIQUAC parameters from the Aspen data based. Nevertheless, a deviation in the activity coefficients has been identified. Hence, considering that activity coefficients values at low pressures depends of K-values, system pressure and equilibrium temperature (Eq 2.3), this difference is possibly due to a slight shift in these parameters.

Conclusion

Isobaric A process for the Deoxydehydration of glycerol into allyl alcohol using 2-hexanol or 4methyl-2-pentanol (MIBC) as H-Donor, including products separation, was developed and modelled with Aspen Plus. The processes are based on our experimental results and consist of four processing subsystems: Allyl alcohol production, Solvent recovery, Allyl alcohol purification and Solvent recycle. Based on the process model, it was possible to obtain allyl alcohol with a purity of 99.99%. Compared to the 2-hexanol process, a high overall process yield (OPY) was obtained (75.6%) in the MIBC process, and therefore, the use of this last solvent was evaluated as much more favorable, notably since it yielded 4-methyl-2-pentanone (MIBK) as a valuable co-product. However, due to the high energy demand of the MIBK purification, the MIBK recycling was implemented as alternative approach. The latter allowed to decrease the energy consumption from 2591.52 kW to 1803.33 kW notably due to the narrower MIBK purification column (2395.12 Kg/h vs. 302.02 Kg/h). However, the OPY decreased from 76.6 % to 57.7 % in that case.

Supporting information

Introduction

Allyl alcohol is a promising platform molecule due to its broad range of applications.

Its derivatives are present in perfume, pharmaceutical and food formulation. In addition, this molecule is required for the production of allyl diglycol carbonate, 1,3-propanediol, poly (styrene-allyl alcohol), etc., which are used as plasticisers, crosslinking agents, and coating additives [1][2] . Currently, the commercial production of allyl alcohol relies on fossil fuels since it is commonly produced by vapour-phase acetoxylation of petrol-based propylene, followed by liquid-phase hydrolysis reaction [3] . Nevertheless, because of declining petroleum resources, the chemical industry is currently facing the challenge of developing bio-based production processes [4] . Several renewable sources can be envisaged as starting material for the synthesis of allyl alcohol whereby the most promising onenotably in terms of carbon economyis glycerol. Glycerol is the by-product formed during the transesterification of vegetable oils for the production of biodiesel. The constant growth of the biodiesel production makes glycerol widely available. Additionally, to ensure the sustainability of the biodiesel industry, the valorization of glycerol is a key adjustment factor [5] .

The Deoxydehydration (DODH) of glycerol to allyl alcohol is a promising valorization strategy, which -to date -has been only marginally investigated. Generally, the DODH reaction removes two adjacent hydroxyl groups from vicinal diols yielding the corresponding alkene, for example, allyl alcohol in the case of glycerol (Figure 3.1) [6][7] . This reaction is typically catalyzed by rhenium based catalyst and requires a stoichiometric reductant such as H2 or a secondary alcohol [8] . The importance of coupling the catalyst and process design at early stages in the technology development has been demonstrated recently for the DODH reaction of glycerol to allyl alcohol using a 5%Ag/ZSM-5 catalyst [5] . This latter system exhibited a 21% yield in allyl alcohol operating in the presence of molecular hydrogen at 40 bar of pressure. The process model developed comprises a gas-phase fixed-bed reactor, three flash separators, five distillation columns and a liquid-liquid column extraction. However, the low selectivity, the large energy consumption implied by the complex separation scheme and the treatment of relevant amounts of waste waters makes this model a rather costly process [5][9] .

We have recently summited an efficient system of conversion of glycerol to allyl alcohol using 10%ReOx/CeO2 as a heterogeneous catalyst in combination of 2-hexanol or 4-methyl-2pentanol (MIBC) as a reductant [10] . The corresponding catalyst showed reusability during three cycles of reaction, and therefore, their potential to scale-up to a continuous process.

Nevertheless, considering that an industrial-scale production includes additional process such as separation of the product, recovery of solvent and regeneration of catalyst, the technical feasibility of the whole process must be determined [11][12] . The aim of this study was the development of a process design for the DODH reaction of glycerol to allyl alcohol over a Ceria-supported Rhenium oxide catalyst for two different solvents: MIBC and 2-hexanol. The kinetic parameters of each DODH reaction were experimentally estimated and afterwards used in the process modelling. For the 2-hexanol process (Process 1), in order to respect to the principles of green chemistry and carbon economy, a regeneration of 2-hexanol was proposed (Figure 3.2) using commercial catalysts. For the MIBC process (Process 2), the production and valorisation of MIBK was chosen as alternative.

OH

MIBK is a valuable chemical used as a solvent in paints, inks, adhesives, but also a precursor in the syntheses of pesticides and surfactants [13] . The effect of the MIBK concentration in the DODH reaction results was also addressed.

The process modelling was performed in four subsystems: Allyl alcohol production, Solvent recovery, Allyl alcohol purification and Solvent recycle. The different scenarios were ranked considering equipment design, masse balance and energy analysis consumption.

Experimental and methodology

Conversion of glycerol to allyl alcohol via Deoxydehydration reaction

The synthesis of the catalyst was performed as described in [10].

DODH reaction -Kinetic parameters

DODH of glycerol was carried out in a 50 mL autoclave (Parr 4597) equipped with a mechanic stirrer. The autoclave was loaded with 17 ml of reductant and 0.77 g of catalyst in air atmosphere. 4-methyl-2-pentanol (MIBC) and 2-hexanol (sigma Aldrich, 99%) were used as reductants. The reaction system was stirred and heated to reaction temperature at 3°C/min. Then, 8 ml of a solution of glycerol/Reductant (10 wt % Glycerol) -prepared previously -were pumped to the reactor with a flow rate of 10mL/min. The batch reactor was assumed to be perfectly mixed after 2min, where the starting point was set. Samples of 200 µl were collected every 15 min at the beginning of the reaction and then every 30 min. Glycerol concentration was determined by gas chromatography, using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID). Glycerol conversion (XGlycerol) was calculated as XGlycerol = (CGlycerol 0 -CGlycerol t )/ CGlycerol 0 , where CGlycerol 0 is the initial concentration of glycerol and CGlycerol t is the glycerol concentration at reaction time t.

Hydrogenation of 2-hexanone in batch conditions.

Hydrogenation of 2-hexanone was performed in a SPR system (Screening Pressure Reactor from Freeslate) equipped with 24 parallel stainless steel batch reactors of 6 mL each. Three hydrogenation catalysts were tested such as 1 wt. % Pt/ɣ-Al2O3 (Alfa Aesar), 5 wt. % Pd/C (sigma Aldrich) and Pt50Pt50/TiO2 [14] . Prior the catalytic test, the corresponding catalysts were reduced in situ under pure hydrogen (30 mL/min) at 2.68 bars for 3 h. Temperature ramp was 5 °C/min up to the temperature of reduction of 350°C. Once the reactivation protocol was completed, the reactors vessels was hermetically sealed and transferred and loaded into a glove box -to avoid the re-oxygenation of the metalswith 2ml of a rich solution of 2-hexanol containing 3 wt.% of 2-hexanone. The catalytic hydrogenation of 2-hexanone was carried out at 70 °C under 4 bar of pure H2. The stirring speed was maintained at 600 rpm and the overall pressure and the temperature were kept constant for 6 hours. 2-hexanone concentration was determined by gas chromatography, using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID).

Influence of MIBK concentration in DODH reaction

Influence of MIBK concentration on DODH catalytic performance was tested using different conditions (0, 15% and 25%wt in MIBC). Catalytic test for DODH reaction were performed in a pressure resistant glass tube equipped with a magnetic stirring bar charged with glycerol (92 mg, 1 mmol, purity in water >99%), 100 mg of catalyst, and 3.3 mL of MIBC. The vessel was tightly sealed by a screw cap and the mixture was stirred (1300 rpm) in an oil bath maintained at 175 ˚C for 2.5 h. After reaction, the solution was cooled to room temperature and placed under ultrasonic irradiation for 5 min at 40 °C to ensure a good homogeneity in a further analysis. The conversion and yield were determined by gas chromatography, using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID).

Modelling and Simulation

Simulation of the allyl alcohol production from glycerol using 2-hexanol and MIBC as reductants, was carried out using Aspen Plus V11 (Aspen technology Inc., USA).The process modelling was performed in four subsystems: Allyl alcohol production (S1), Solvent recovery (S2), Allyl alcohol purification (S3) and solvent recycle (S4). The process flow diagrams using 2-hexanol and MIBC are displayed in Figure 3.3 and Figure 3.4, respectively.

Deoxydehydration of glycerol into Allyl alcohol was modelling at high yield by using the estimated kinetic parameters associated to 10%ReOx/CeO2 catalyst in combination of 2-hexanol or 4-methyl-2-pentanol (MIBC) as reductants. For both process, the main challenge was the complete recovery and purification of Allyl alcohol. Nevertheless, given the nature of each solvent and the corresponding ketone, additional challenges were defined for each process design, and therefore, two different strategies were proposed. In 2-Hexanol process, considering the high commercial price of solvent, separation process was targeted towards reduce as much as possible the waste of 2-Hexanol, whereas in MIBC process, the maximum recovery and purification of MIBK was the main focus, due to its potential as valuable co-product. The objective in the first step of separation (S2), was to recover the highest amount of allyl alcohol and water on the top of the column, reducing at the same time the waste of solvent and ketone on the top via atmospheric distillation. Next, the mixture containing the lighter components were sent to Allyl alcohol purification subsystem (S3) in order to separate allyl alcohol from water via extractive distillation. Finally, the diluted mixture of ketone in solvent (< 4 wt. %)obtained from the bottom of RC -was sent to solvent recycle subsystem (S4), where two different strategies were tested: Hydrogenation of 2-Hexanone (Figure 3.2) in the case of 2hexanol and purification of MIBK via atmospheric distillation in the case of MIBC. Thus, with the aim to estimatein the proper manner -physical properties of components, including vapor liquid equilibrium of binary mixtures, thermodynamic model was a key choice within the process.

Allyl alcohol production (S1)

Allyl alcohol production (S1), was performed using a cascade of five continuous stirred tank reactors (CSTR modules). The DODH reaction at steady state, Figure 3.5 and Figure 3.6, was assumed to follow a power law kinetic model. The constants were determined based on the experimental data obtained in batch conditions. Resident time and reactor volume were adjusted for a fixed conversion of 96% [10] .

OH HO OH OH + OH O + H O H + 10wt%ReOx/CeO2

Solvent recovery (S2)

The design of the recovery columns was carried out using short-cut methods and rigorous models available in the simulation package. The design process followed is shown in Figure 3.7.

The short-cut method DSTWU, was used to make a first estimation of the minimum reflux ratio, minimum number of theoretic stages, location of the feed stage, distillate to feed ratio and the products split. Then, the latter information was supplied in a rigorous model column (RADFRAC) and a sensitivity analysis was performed, in order to study the effect of the main operation variables such as reflux ratio (RR), number of stages (NS), and feed stage (FS).

Since NS and RR affect capital cost and operating cost, respectively [19][20][21] , the following ranges were considered as design specifications: 1.1 Rmin ≤ RR≤ 1.5 Rmin and 2 Nmin ≤ NS ≤ 2.5

Nmin [19][20][21] , where Rmin is the minimum reflux ratio and Nmin is the minimum number of stages. The feed temperature was constrained to saturated liquid, in order to avoid thermodynamic inefficiencies [20] and a pressure of 101.32 kPa was fixed in the condenser, with a pressure drop of 0.7 kPa/tray [19] . Recovered Allyl alcohol percentage (RAllyl D ) was calculated

Allyl alcohol purification (S3)

Allyl alcohol purification subsystem included two columns: an extractive distillation column (EDC) and an entrainer recovery column (ERC). Their corresponding design algorithms, for processes 1 and 2, are shown in Figure 3.8. The EDC column was simulated using the Aspen plus RADFRAC routine. Initial values were based on the literature [16] [17] [18] .

Sensitivity analyses were performed, in order to study the effect of the main operation variables such as Entrainer to feed ratio (ENTFR), number of stages (NS), reflux ratio (RR) and distillate to feed ratio (DTFR). The number of stages (NS) was fixed in the following range: 2 Nm ≤ NS ≤ 2.5 Nm. Where Nm is the minimum number of stages to obtain a mole fraction of allyl alcohol ≥ 0.9999 and a recovery percentage of >99%, in the distillate (See results section). The key design variables were NS, RR and FS, and the corresponding design ranges were defined in Algorithm 2 (Figure 3.8). The feed temperature was constrained to saturated vapor in EDC column and liquid in ERC column. For both columns, a pressure of 101.32 kPa was fixed in the condenser, with a pressure drop of 0.7 kPa/tray [19] .

Solvent recycle (S4)

In Process 1, the Hydrogenation of 2-Hexanone (Figure 3.2) was simulated using the Stoichiometric reactor (RStoic) module. In the case of MIBK purification (Process 2) the column was design according to algorithm 3 presented in Figure 3.9. The column was calculated using short-cut methods and rigorous models available in simulation package.

Results and discussion

Experimental DODH results

DODH reaction -Kinetic parameters

The time profile for the DODH reaction catalyzed by Ceria-supported Rhenium catalyst (10%ReOx/CeO2-HSA-5), using 2-hexanol and MIBC are presented in Figure 3.10. For both reductants, the rate of the glycerol conversion was assumed to follow a first-order dependence with an Arrhenius temperature association for the first-order rate constant (ki) (Linear fit Figure 3.S1). The activation parameters were determined from Eyring and Arrhenius plot, shown in Figure 3.11. The activation enthalpy (ΔH # ) and entropy (ΔS # ) were deduced from the linear fit of the Eyring plot (Eq 3.1), along with the activation energy (Ea) and pre-exponential factor (A) from the corresponding Arrhenius plot (Eq 3.2). A summary of the kinetics parameters for both reactions are reported in As reported in Table 3.2, the activation parameters of the DODH reaction were different for each solvent: 54.9 kJ/mol for MIBC and 79.2 kJ/mol for 2-Hexanol. Hence, for this reaction system, Ea values were higher than observed for homogeneous glycerol DODH (25.1 kJ/mol) [22] and lower than observed for heterogeneous glycerol DODH catalyzed by nanoparticles of rhenium oxide (ReOx NPs) (97 kJ/mol) [23] . In addition, comparing kinetic constant values obtained with each solvent at 150°C, higher reaction rate (almost twice) is observed when the solvent/reductant is 2-Hexanol.

Hydrogenation of 2-hexanone

With the aim to obtain reliable simulation of 2-hexanone hydrogenation as solvent recovery strategy for process 1, three potential hydrogenation catalysts were tested under standard conditions [24] [25][26] [27] . As observed in Table 3.3, 1 wt. % Pt/ɣ-Al2O3 (Alfa Aesar) showed the best catalytic performance -a yield of >99% -making this catalyst suitable for the solvent regeneration process. This result is consistent to literature, where platinum has showed a high catalytic performance over ketones hydrogenation in mild conditions [26] [27] . Likewise, the low catalytic performance of Pt50Pd50/TiO2 and 5wt. % Pd/C would seem to indicate a negative impact of Pd metal on the hydrogenation of 2-Hexanone.

DODH performance with MIBK concentration

Influence of MIBK concentration on DODH of glycerol performance was carried in order to evaluate experimentally the use of this parameter in the further MIBK recovery. As shown in Figure 3.12, there was no evidence of a significant decrease in DODH yield, up to a maximum concentration of MIBK of 25 wt. %. Conversion and selectivity remain stable at 99.9% ± 3.8 % and 85.0 % ± 2.0 %. Hence, this parameter could be considerate within a MIBK purification context.

Process modelling

The process flow diagrams for Process 1 (2-Hexanol) and Process 2 (MIBC) were previously shown in Figure 3.3 and Figure 3.4, respectively. The optimal design of the reactors and separation units for both process will be discussed (within each subsystem), including the principal decisions. Both process were developed for a fixed feedstock processing rate of 1 kmol/h of glycerol and 24 kmol/h of reductant (2-hexanol and MIBC) at the reactor inlet.

Allyl alcohol production (S1)

Deoxydehydration of Glycerol to Allyl alcohol was performed in order to achieve 96% of yield (96% of conversion and 100% of selectivity) at 170 °C for both processes. The reaction was performed using a cascade of five identical CSTR reactors. Based on the kinetic parameters presented earlier in Table 3.2, the kinetic constants were extrapolated to 170°C, using a glycerol/catalyst masse ratio of 0.19. The total resident time was estimated to 24.33 and 51.85 min, for 2-Hexanol and MIBC, respectively. Compared to MIBC process, the lower resident time of 2-Hexanol processby half -could be linked to the differences in reaction rate, explained previously. Hence, considering a fixed flow rate of 3.8 m 3 h -1 , the total volume for the reaction was determined to 1.54 m 3 and 3.31 m 3 , using 2-Hexanol and MIBC, respectively.

The corresponding modelling parameters are summarized in Table 3.4. 3.089x10 -3 1.452x10 -3 a Calculated for a glycerol/catalyst masse ratio of 0.19

Solvent recovery (S2)

Recovery column (RC) design was carried out in accordance with algorithm 1 (Figure 3.7). The corresponding sensitivity analysis is shown in Figure 3.13. As observed in Figure 3.13 (a) and (b), for both processes, a recovery percentage of allyl alcohol in distillate (R D Allyl) of 99.99% was achieved for different possible combinations of NS and RR. Nevertheless, unlike MIBK recovery, an increase in the RR improved the recovery of 2-hexanol in the bottom stream.

Hence, the optimal RR values were 1.5Rmin for Process 1 and 1.1Rmin for Process 2, with corresponding NS of 2.14Nmin and 2.04Nmin, respectively. The design of ERC column for both process (1 and 2) allowed a recovery percentage and a molar fraction of entrainer of 99.99% and 0.9999 (Figure 3.S3). Optimal design parameters are reported in Table 3.S2.

Solvent recycle (S4)

For Process 1, the regeneration by hydrogenation of the 2-hexanone (Figure 3.2) and the later direct solvent recycle was proposed (Figure 3.3). The hydrogenation reactor was simulated as a Stoichiometric reactor (RStoic) with yield of 99.85%. The latter value was chosen according to the experimental results (Table 3.3), previously discussed.

For Process 2, the direct MIBK purification was proposed as alternative (Figure 3.4). In this case, a purification column (MPC) was designed according to algorithm 3 (Figure 3.9).

Sensitivity analysis is shown in Figure 3.15 (a). As observed, there are a number of combinations of NS and RR for achieving a recovery percentage and mass fraction of MIBK of 99.99% and 0.9997, respectively. Nevertheless, an optimal RR and NS values of 72.41 and 95 was chosen, representing 1.5Rmin and 2Nmin, respectively. The optimal design parameters are reported in Table 3.7. The high Rmin value are linked to the low relative volatility of MIBK/MIBC binary mixture (1.49 <αMK/MB < 1.76) and the low mass fraction of MIBK in the column feed stream (0.035) [20] , involving a high energy consumption of the column. Thus, for the purpose of counteract this additional challenge, an alternative to Process 2 was studied - The Recovery column (RC)R, Extractive distillation (EDC)R and entrainer recovery (ERC)R columns were optimized again, following Algorithm 4 as indicated in Figure 3.S2, for Process 3. For the Recovery column (RC)R, optimum distillate to feed ratio were recalculated for a split ratio range, between 0.02 and 0.2. As shown in Figure 3.17, the split of the bottom stream (B-RC-R in Figure 3.16) allowed to increase the concentration of MIBK up to 20 wt.%. Hence, for a split ratio of 0.112 the distillate to feed ratio of the RC column had to be increase from 0.1285 to 0.1267 to keep a complete allyl alcohol recovery in the distillate and a MIBK concentration of 14.8wt. % in the bottom. In addition, the residual MIBK in the distillate was decreased from 12.5 to 11.3%.

Having a MIBK concentration to 14.8 wt. % at inlet stream (INMPC-R in Figure 3.16), the MIBK purification column (MPC)R was redesign according to algorithm 3 (Figure 3.9). Sensitivity analysis is shown in Figure 3.15, (b). A recovery percentage and mass fraction of MIBK of 99.99% and 0.9999 was achieved, respectively. Comparing with MPC column (Process 2), a significant decrease in Rmin from 48.27 to 11.77 was obtained. Furthermore, the recycling decreased the size of the MPC column from 2395.12 Kg/h (Process 2) to 302.02Kg/h (Process 3), corresponding to a significant decrease in the investment costs and energy consumption (cf 3.3.4 Energy consumption). The optimal reflux ratio value was 17.66 (1.5 Rmin). Optimal design parameters are reported in Table 3.7.

Wasted MIBC in distillate [%]

Redesign of Allyl alcohol purification subsystem (S3) -process 3.

Given the increase of MIBK amount on Allyl alcohol purification subsystem (S3) of process 3, some operating parameters were sequentially readjusted in order to match the design target in both columns (Figure 3 Then, Reflux ratio was increased to 2.877, allowing a complete entrainer recovery with a purity of 0.9999.

General mass balance

The process mass balance is given for the full scale system in Table 3.8. All processes give an Allyl alcohol purity of 0.9999. The overall process yield (OPY) was calculated as the molar ratio between the output and input, defined by Eq 3.3 and Eq 3.4 for process 1 and 2-3, respectively. Where ni is the mole flow of each stream. The corresponding OPY were 45.0%, 75.6% and 57.7%, respectively. With respect to the yield in allyl alcohol, all processes are similar, with about 55 Kg/h. Hence, the main difference lies in the solvent loss: in Process 1 the solvent loss is 21.3 Kg/h, corresponding to 41.7 % of the solvent inlet; in Process 2, the solvent loss is 46.9 Kg/h (32.3% of solvent inlet) and 50.3 Kg/h for Process 3 (34.2% of solvent inlet).

Composition values and process masses are given for the full scale system approach in Table

Energy consumption of the process

Based on the process simulation results, Table 3.9 presents the energy analysis performed for each process. The energy consumption estimation was based on the thermal energy required by the heat exchangers, reboilers, condensers, reactors and pumps. To reduce the total energy requirement of the processes, a heat exchange network (HEN) was designed via ASPEN energy analyser. The energy integration resulted in significant reductions in demand for both the hot and the cold utility requirements by 35.78, 18.76 and 31.47% in Process 1, 2 and 3, respectively. Thus, the energy efficiency of each process was calculated (defined by Eq 3.5 [11] ). Process 1 (2-hexanol) showed the highest energy efficiency of 22.71 % compared to Process 2 and 3, which showed 13.72% and 21.30%, due to the supplementary column used for the MIBK purification. Comparing the MIBK processes (Process 2 and 3), a large decrease in energy consumption was evidenced for Process 3 with a total consumption of 1803.33 kW compared to 2591.52 kW for Process 2. This decrease was possible through the MIBK recycling strategy resulting in a significantly narrower MIBK purification column (MPC).

The energy balance was validated corresponding to the difference between cooling system and heating system, including electricity. Carbon footprint was also estimated, according with the following order from high to low: Process 2(MIBC)>Process 3(MIBC)> Process 1 (2-Hexanol).

𝐸𝑛𝑒𝑟𝑔𝑦 𝐸𝑓𝑓. = 𝑂𝑢𝑡𝑝𝑢𝑡 𝑓𝑙𝑜𝑤 𝑒𝑛𝑒𝑟𝑔𝑦

𝐼𝑛𝑝𝑢𝑡 𝑓𝑙𝑜𝑤 𝑒𝑛𝑒𝑟𝑔𝑦 +𝑛𝑒𝑡 𝑝𝑟𝑖𝑚𝑎𝑟𝑦 𝑒𝑛𝑒𝑟𝑔𝑦 * 100 % Eq 3.5

Conclusion

A process for the synthesis of Allyl alcohol via DODH of glycerol over a Ceria-supported Rhenium oxide catalyst was modelled for two different solvents: 2-hexanol (Process 1) and MIBC (Process 2). The processes were designed for a glycerol flow rate of 1 kmol/h. For a reliable simulation of the reaction, the kinetic parameters of the DODH reaction were experimentally determined for both solvents. In comparison, the reaction rate with 2-hexanol was almost twice as high as for MIBC. The reactor was dimensioned for an allyl alcohol yield of 96%, whereby a larger reaction vessel was required when using MIBC. Given the nature of each solvent and the corresponding co-produced ketone, product separation design targeted the reduction of the solvent loss for 2-Hexanol process, whereas for the MIBC process, the maximum recovery and purification of MIBK was focused. The product recovery was performed via atmospheric distillation. However, given the production of water during the reaction, extractive distillation was proposed as purification technique for the purification of allyl alcohol, where N-methyl-pyrrolidone (NMP) was used as an entrainer. Thus, for both processes, it was possible to obtain allyl alcohol -around 55 kg/h -with a purity of 99.99%.

Compared to the 2-hexanol process a high overall process yield (OPY) was obtained in the MIBC process (75.6% vs.45%), whereby one can conclude that the use of MIBC is more favorablenotably due to the fact that 4-methyl-2-pentanone (MIBK) as obtained as a valuable co-product. However, the main drawback of Process 2 lies in the high energy requirement for the MIBK purification due mainly to the low relative volatility of MIBK/MIBC binary mixture (1.49 <αMK/MB < 1.76) and the low mass fraction of MIBK in the column feed stream (0.035).

In order to optimize the latter, an optimized Process (Process 3) was proposed, based on the recycling of the MIBC/MIBK mixture in order to increase the concentration of the using the latter. The MIBK recycling strategy, allowed the reduction of the MIBK purification column by a factor 8 (302.02 Kg/h vs. 2395.12 Kg/h) resulting in a decrease of the energy consumption and investment costs. However, as a drawback, the OPY increased for Process 3, due to the increased loss of MIBK in the product recovery subsystem (S2). In any scenario, the MIBC process proved to be a feasible strategy from a technical point of view, which could potentially be used as starting point for the development of a large scale DODH process. 2-Hexanone kmol/h 0,00 0,00 0,00 0,96 0,67 0,00 0,00 0,29 0,00 0,00 0,29 0,29 0,00 0,00 0,67 Allyl kmol/h 0,00 0,00 0,00 0,96 0,00 0,00 0,00 0,96 0,00 0,96 0,00 0,00 0,00 0,00 0,00 Water kmol/h 0,00 0,00 0,00 1,92 0,00 0,00 0,00 1,92 0,00 0,00 1,92 1,92 0,00 0,00 0,00 Glycerol kmol/h 0,00 0,96 1,00 0,04 0,04 0,00 0,04 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,04 NMP kmol/h 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 13,11 0,00 13,11 0,00 13,11 Allyl kmol/h 0,00 0,00 0,00 0,96 0,00 0,00 0,00 0,00 0,96 0,96 0,00 0,00 0,00 0,00 0,00 MIBC kmol/h 1,42 0,00 24,00 23,04 22,58 22,58 0,00 22,58 0,46 0,00 0,00 0,46 0,46 0,00 0,00 MIBK kmol/h 0,00 0,00 0,00 0,96 0,84 0,84 0,84 0,00 0,12 0,00 0,00 0,12 0,12 0,00 0,00 Glycerol kmol/h 0,00 0,96 1,00 0,04 0,04 0,04 0,00 0,04 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Water kmol/h 0,00 0,00 0,00 1,92 0,00 0,00 0,00 0,00 1,92 0,00 0,00 1,92 1,92 0,00 0,00 NMP kmol/h 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 3,69 0,00 3,69 0,00 0,00 0,00 0,00 0,00 0,00 0,00 Water kg/hr 0,00 0,00 0,00 34,59 0,00 0,00 0,00 0,00 34,59 0,00 0,00 34,59 34,59 0,00 0,00 NMP kg/hr 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 0,00 1601,84 1601,84 0,01 1601,83 9,91E-03 Glycerol kmol/h 0,000 0,946 1,000 0,054 0,054 0,006 0,000 0,006 0,000 0,000 0,000 0,000 0,000 0,000 0,000 Water kmol/h 0,000 0,000 0,000 1,892 0,000 0,000 0,000 0,000 1,892 0,000 0,000 1,892 1,892 0,000 0,000 NMP kmol/h 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 ,970 0,557 0,000 0,557 0,000 0,000 0,000 0,000 0,000 0,000 0,000 Water kg/h 0,000 0,000 0,000 34,083 0,000 0,000 0,000 0,000 34,083 0,000 0,000 34,084 34,083 0,000 0,000 NMP kg/h 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 0,000 was evaluated via process modelling, in Chapter 3. Two scenarios were studied using 2-hexanol and MIBC as reductants, respectively. In both cases, extractive distillation was used as main strategy of allyl alcohol purification, where N-methyl-2-pyrrolidone was implemented as entrainer. Both strategies allowed an allyl alcohol purify of 99.99%. Compared to the 2-hexanol process, the high overall process yield (OPY) obtained in the MIBC process (75.6% vs. 45%) allowed to conclude that the use of MIBC is more favorable, notably since it yielded pure 4methyl-2-pentanone (MIBK) as valuable co-product. The main drawback in the use of MIBC was the high energy requirement for the MIBK purification. Hence, the MIBK recycling was implemented as alternative approach and a decrease in energy consumption was achieved, notably due to the decrease of the MIBK purification column (302.02 Kg/h vs 2395.12 Kg/h).

Supporting information

Mass

On the other hand, the OPY negatively impacted and decreased from 76.6% to 57.7% due to the increased loss of MIBK. In any case the MIBC process showed be a feasible strategy from a technical point of view, which could potentially be used as starting point for the development of a large scale DODH process.

In conclusion, we have demonstrated the technical feasibility of an integrated process for the DODH reaction of glycerol to allyl alcoholnotably via a process simulation. However, in order to validate the latter, further research is necessary, as we will discuss in the next section.

Outlook

As in all catalytic processes, the understanding of the reaction mechanism is essential to attain the best possible performances. Up to now, the reaction pathway has only marginally been studied when a secondary alcohol is used as a solvent-reductant and a number of questions remain to be answered. So far, research on the DODH mechanism has considered only ketone formation as parallel reaction, nevertheless, considering that a maximum carbon balance of 86% was achieved at complete conversion, it would be interesting to deeply investigate all possible reaction pathways between glycerol, allyl alcohol, solvent and ketone under the applied reaction conditions.

At the end of this thesis, the technical feasibility of an integrated process for the DODH reaction of glycerol to allyl alcohol was demonstrated through a process simulation. However, even if the latter is based on experimental data, the results from the simulation should be validated Concerning the allyl alcohol purification, the extractive distillation could be improved with an extensive research on liquid-vapor equilibrium of pseudo-binary mixtures. In fact, whereas the extractive distillation of the binary allyl-water using N-methyl-2-pyrrolydone as entrainer is well studied, ketone-water and solvent-water azeotropes might have an important role in the overall process yield. Furthermore, the purge of these mixtures is responsible for the major amount of waste of the process. Hence, an entrainer screening should be performed to establish a largest change in the volatility of allyl alcohol/water, ketone/water and solvent/water binary mixtures and therefore, achieving an increased recovery of the solvent and the co-produce ketone, which would positively affect the economic viability of the process. Finally, considering an industrial application, the purity of glycerol is an interesting parameter that should be further investigated. In fact, glycerol is the main by-product from biodiesel production and contains several impurities, such as inorganic salts, methanol and water. Hence, if the deoxydehydration reaction could use glycerol with lower purity as raw-material, the economical viability would be further increased, making it an attractive glycerol valorisation strategy for biodiesel producers.

et 2 -

 2 hexanone et 4-méthylpentan-2-one (MIBK) sont les cétones coproduites lors de la réaction DODH, respectivement. Les données expérimentales de VLE ont été mesurées et ajustées en utilisant les modèles thermodynamiques NRTL, UNIQUAC et Wilson. Aucun azéotrope n'a été trouvé et la cohérence thermodynamique a été vérifiée avec succès, en utilisant les tests Herinton, Van Ness, composants purs et Redlich-Kister.

Figure 1 . 3 .

 13 Figure 1.3. Particle distribution of (a) 2.5 wt.% ReOx/CeO2 (b) 10 wt.% ReOx/CeO2+SiO2 (c)15 wt.% ReOx/CeO2+SiO2 and DF-TEM image of (d) 10 wt.% ReOx/CeO2+SiO2 and (e) 15wt.% ReOx/CeO2+SiO2.

Figure 1 . 2 .

 12 Figure 1.2. XRD patterns for ReOx/CeO2 catalyst (a) support CeO2+SiO2 (b) 2.5 wt.% ReOx/ CeO2+SiO2 (c) 5 wt. % ReOx/ CeO2+SiO2 (d) 10 wt.% ReOx/CeO2+SiO2 (e) 15 wt.% ReOx/CeO2+SiO2

Figure 1

 1 Figure 1.4. HAADF-STEM and corresponding STEM-EDS elemental mapping images of 10 wt.% ReOx/ CeO2+SiO2 (a)Representative HAADF-STEM image of precipitates, (b,c,d,e) STEM-EDS maps for Re, Ce, O and Si, respectively.

Figure 1 . 6 .

 16 Figure 1.6. TPR profiles of CeO2-HAS-5 (a) and 10 wt.% ReOx/CeO2-HAS-5 (b). Conditions: Sample (50 mg) and H2/Ar (5%v/v, 50 cc/min) at heated rate of 10K/min.

( a )

 a Reaction conditions: Glycerol (1.0 mmol), Catalyst (100 mg), 2-hexanol (3.3 mL), 175°C (oil bath), 1300 rpm, 2,5 h (b) Conversion and yield on the basis of glycerol, determined by GC analysis with benzene as an internal standard.

Figure 1 .

 1 Figure 1.S2. XRD patterns of all supports and catalysts : using a Si-based hard template (before and after NaOH treatment, respectively), (a, b) Commercial support CeO2 (HSA-5) (c, d) 10 wt.% ReOx/ CeO2 (HSA-5) (e, f) CeO2+SBA-15 (g, h) 10 wt.% ReOx/CeO2+SBA-15 (i, j) CeO2+SBA-15 (k, l) 10 wt.% ReOx/CeO2+SBA-15; and Carbon-based hard template (m) CeO2+Carbon before calcination (n) CeO2+Carbon after calcination (o) 10 wt.% ReOx/CeO2+Carbon.

Figure 1 .

 1 Figure 1. S1. XRF sum spectrum calculated out of 33 spectra of 10 wt% ReOx/CeO2+SiO2 (a) and 10wt% ReOx/CeO2+SBA-15 (b) samples, with NaOH treatment.

  until equilibrium was reached. Equilibrium condition is assumed when temperature variations are less than 0.1 K for at least 30 min at constant pressure. The temperature and pressure variations are monitored in real time by statistical control charts. Once the equilibrium condition attainted, samples of liquid and condensed vapor were taken for gas chromatography analysis. All experiments were carried out at 101.32 kPa of pressure. Between 15 to 22 equilibrium points were generated for each binary system. To verify the performance of the apparatus, vapor pressure data of pure components were also measured, and the coefficients of Antoine extended equation were fitted. Approximately 18 to 20 equilibrium points for each pure component were measured.

Figure 2 . 1 .

 21 Figure 2.1. Apparatus Fisher VLE 602 used in this work. 1: Reservoir with immersed rod heater. 2: Condenser. 3: Vapor-phase temperature sensor. 4: Liquid-phase temperature sensor. 5: Mixer chamber. 6: Coolant water connection. 7: Pressure control line. 8: Liquid sampling port. 9: Vapor sampling port. 10: Condenser. 11: Liquidphase septum. 12: Vapor-phase septum.

Figure 2 . 2 .

 22 Figure 2.2. Vapor pressure for 2-hexanol, MIBC, 2-hexanone, MIBK and Allyl alcohol. The continuous blue line denotes the Antoine equation with regressed parameters. (•) represents experimental data and (○) reported data from the NIST database.

Figure 2 . 4 .

 24 Figure 2.4. Phase diagram Txy (left) and plot of Lnɣ1, Lnɣ2 and G E /RTx1x2 vs x1 at 101.32 kPa (right) for Allyl alcohol/2-Hexanol and Allyl alcohol/MIBC binaries. (□) Experimental data (○) Experimental Lnɣ1, Lnɣ2 (•) Experimental G E /RTx1x2. Green solid line, red dotted line and blue points correspond to UNIQUAC, NRTL and Wilson adjustment.

Figure 2 . 5 .Figure 2 . 6 .

 2526 Figure 2.5. Phase diagram Txy (left) and plot of Lnɣ1, Lnɣ2 and GE/RTx1x2 vs x1 at 101.32 kPa (right) for 2-Hexanone/2-Hexanol and MIBK/MIBC binaries. (□) Experimental data (○) Experimental Lnɣ1, Lnɣ2 (•) Experimental G E /RTx1x2. Green solid line, red dotted line and blue points correspond to UNIQUAC, NRTL and Wilson adjustment

Figure 2 . 7 .

 27 Figure 2.7. Diagram (x-y) (left) and plot of Lnɣ1, Lnɣ2 and G E /RTx1x2 vs x1 at 101.32 kPa (right) for MIBK/MIBC system. Green solid line, red dotted line and blue points correspond to simulated equilibrium using UNIQUAC parameters from this work and Aspen data based, respectively.

Figure 2 .

 2 Figure 2.S1. Ln (ɣ1/ ɣ2) vs x1 plot of all binary systems, used in the thermodynamic consistency tests based on Gibbs-Duhem equation.

Figure 3 . 1 .Figure 3 . 2 . 2 -

 31322 Figure 3.1. Rhenium-catalyzed Deoxydehydration of glycerol into allyl alcohol in the presence of a reductant (referred as "red").

Figure 3 . 3 .

 33 Figure 3.3. Process 1: flow diagram for the integrated allyl alcohol production via DODH of glycerol using 2-hexanol. DODH-RXN: Reactor of Deoxydehydration of glycerol. HYD-RXN: Hydrogenation reactor. RC: Recovery column. EDC: Extractive distillation column. ERC: Entrainer recovery column.

Figure 3 . 4 .

 34 Figure 3.4. Process 2: flow diagram for the integrated allyl alcohol production via DODH of glycerol using MIBC. DODH-RXN: Reactor of Deoxydehydration of glycerol. RC: Recovery column. MPC: MIBK purification column. EDC: Extractive distillation column. ERC: Entrainer recovery column. LV Equilibria

Figure 3 . 5 .Figure 3 . 6 .

 3536 Figure 3.5. Deoxydehydration of glycerol into allyl alcohol in the presence of 2-hexanol

as

  RAllyl D = 100*(mAllyl D / mAllyl inlet ), where mAllyl D is the Allyl alcohol mass flow at distillate and mAllyl inlet is the Allyl alcohol mass flow at column inlet. Same mathematical treatment was carried out to calculate the wasted 2-Hexanol percentage (WHex D ) and recovered MIBK percentage (RMIBK B ) in distillate and bottom, respectively.

Figure 3 . 7 .

 37 Figure 3.7. Algorithm 1: Recovery column (RC), design for processes 1 and 2. RA = Recovery percentage of allyl alcohol in distillate. RS = Recovery percentage of solvent in distillate. Pc = Condenser pressure

Figure 3 . 8 .

 38 Figure 3.8. Algorithm 2: Extractive distillation (EDC) and Entrainer recovery column (ERC), design for processes 1 and 2. Nm= Minimum Number of stages to obtain a mole fraction of allyl alcohol ≥ 0.9999 and a recovery percentage of 99%. NME= Number of stages using a maximum ENTFR. RW = Recovery percentage of water in distillate. REN = Recovery percentage of Entrainer in distillate. Pc = Condenser pressure.

Figure 3 . 9 .

 39 Figure 3.9. Algorithm 3: MIBK Purification column (MPC), design for process 2. RMK= Recovery percentage of MIBK in distillate. RMC= Recovery percentage of MIBC in distillate.

Figure 3 . 10 .Figure 3 .

 3103 Figure 3.10. Reaction profile for glycerol heterogeneous DODH to allyl alcohol using 2-Hexanol (a) and MIBC (b) as reductants. Raw data (dot), kinetic fitting (dotted line). Conditions: 778mg of catalyst, 30 mL of volume.

Figure 3 . 12 .

 312 Figure 3.12. Influence of MIBK concentration in DODH reaction. Reaction conditions: Glycerol (1.0 mmol), 10wt% ReOx/ CeO2+SiO2 (100 mg), Solvent: MIBC, 175°C (oil bath), 1300 rpm, 2.5 h. Conversion and yield on the basis of glycerol, determined by GC analysis with benzene as an internal standard.

Figure 3 . 13 .

 313 Figure 3.13. Recovery column (RC) -Sensitivity analysis. (a),(c) process 1: 2-hexanol. (b),(d) process 2: MIBC. RAllyl D [%]= Recovered Allyl alcohol in distillate.

Figure 3 . 14 .

 314 Figure 3.14. Extractive distillation column (EDC) -Sensitivity analysis. . (a),(c),(e) process 1: 2-hexanol. (b),(d),(f) process 2: MIBC. xAllyl D [%] = Mole fraction of Allyl alcohol in distillate. . RAllyl D [%] = Recovered Allyl alcohol in distillate.

named Process 3 .

 3 The strategy consisted in the increase of the MIBK concentration in the feed of MPC column by splitting the bottom stream of RC column before further purification, as shown in Figure3.16. The feasibility of this strategyin terms of impact on the allyl alcohol yield in the DODH reactionwas previously validated experimentally in section 3.3.1.3.

Figure 3 . 15 .

 315 Figure 3.15.MIBK purification column (MPC) -Sensitivity analysis. (a) Process 2: Direct purification of MIBK. (b) Process 3: MIBK concentration and further purification. RMK D [%] = Recovered MIBK in distillate, xMK D = Mole fraction of MIBK in distillate.

Figure 3 . 16 .

 316 Figure 3.16. Process 3: flow diagram for the integrated allyl alcohol production via DODH of glycerol using MIBC. DODH-RXN: Reactor of Deoxydehydration of glycerol. RC-R: Recovery column. MPC-R: MIBK purification column. EDC-R: Extractive distillation column. ERC-R: Entrainer recovery column.

Figure 3 . 17 .

 317 Figure 3.17. Sensitivity analysis in (RC)R column -Influence of split of bottom stream in RC column design

  .S2). First, extractive distillation column (EDC)R was redesigned by means of DRTFR and ENTFT parameters. After that, DRTFR and RR were readjusted in entrainer recovery column (ERC)R.. Hence, in the EDC column (Figure3.18, a), an allyl alcohol recovery of 99.8 % was remained by increasing the entrainer to feed ratio value to 5.87 as well as the readjustment of DTFR to 0.2456. The operating conditions of ERC column (Figure3.18, b) were modified due mainly to the increase of entrainer amount. The readjustment of DRTFR to 0.1137 allowed an entrainer mole fraction and recovery of 0.9993 and 99.94%, respectively.

Figure 3 .

 3 Figure 3.18. Process 3: Allyl alcohol purification -sensitivity analysis. (a) Extractive distillation column (EDC)R (b) Entrainer recovery column (EDC)R

Figure 3 .Figure 3 .

 33 Figure 3.S1. DODH model kinetics first order linear fit. MIBC-150C (a), MIBC-140C (b) 2-Hexanol-160C (c) 2-Hexanol-150C (d)

Figure 3 .

 3 Figure 3.S3. Entrainer recovery column (ERC) -Sensitivity analysis. (a) Process 1: 2-hexanol. (b) Process 2: MIBC. R B EN[%] = Recovered Entrainer in bottom, x B EN[%]= Mole fraction of Entrainer in bottom.

  through a demonstratorcorresponding to the first step of the upscaling. Regarding the allyl alcohol synthesis, preliminary tests were carried out in continuous flow (experimental details in annexe A). The DODH reaction using the Ceria-supported Rhenium catalyst (10%ReOx/CeO2-HSA-5) was performed in continuous mode, using MIBC and 2-hexanol. As presented in Figure4.1, the reaction showed a stable catalytic performance during 48 and 39 hours, respectively. Owing to the difficult control of the outlet flow rate, the conversion fluctuated within ±0.9%. The experimental conversion rate was 58.4 ± 0.9% (170°C) and 50.3 ± 0.6% (160°C), using 2-Hexanol and MIBC, respectively. The low selectivity of around 45%± 2% (Figure4.1) at these conversion values indicates either the presence of an intermediate or a degradation product during the DODH reaction (around 15% in carbon balance). However this molecule could not be identified by GC-MS. Considering the reactor volume (V) and flow rate (Q) used, a high conversion rate >80% was expected for both solvents for the applied reaction conditions. The observed lower experimental conversion could result from to a non-ideal performance of the reactor, which indicate a different resident time (τ) caused by low mixing efficiency of the reactor (dead zones)2,3,4 . In order to determine the mixing efficiency of the reactor, the resident time distribution (RTD) of the reactor should be measured.

Figure 4 . 1 .

 41 Figure 4.1. Experimental conversion of glycerol and selectivity in allyl alcohol as a function of time, in continuous flow DODH reaction. (Conditions: V=30mL, Flow rate=0.1 mLmin -1 , Catalyst amount=4.5g). 2-Hexanol-170°C (a) MIBC-160°C (b). XGly = Conversion of glycerol. SAllyl = Selectivity in allyl alcohol. YGly: yield in allyl alcohol. CB: Carbon balance.

Table 2 .

 2 Heterogeneous catalytic activities reported for the production of allyl alcohol via DODH of glycerol

Entry Catalyst Reductant Temperature [°C] Reaction Time [h] Yield [%] Ref.

	1	ReOx/TiO2	3-Octanol	170°C	1	48 (1 st run)	[22]
						54 (7 st run)
	2	ReOx -Au/CeO2	H2	140	52	91	[6]

1.2.1. Synthesis

	All commercial materials were used as received without further purification. A
	commercial mesoporous ceria support (HSA-5) was purchased from Solvay. A ceria-silica
	sample (CeO2+SiO2) was provided by Solvay (ECL9 #1503984). Perrhenic acid solution (75-
	80 wt.% HReO4 in H2O), glycerol (>99 wt. % of purity), allyl alcohol (98 wt.%), tetraethyl
	orthosilicate (TEOS, 98 wt.%), Tetrapropylammonium hydroxide solution (20-25 wt.%
	TPAOH in H2O), Cerium (III) nitrate hexahydrate (Ce (NO3)3*6H2O, 99 wt.%), Activated

Charcoal and solvents (99 wt.%) were obtained from Sigma Aldrich.

1.2.2. Support preparation

1.2.2.1. Hard template SBA-15

Table 1 .

 1

1. Textural properties of Rhenium oxide-based catalysts and the corresponding supports (a)Catalyst recovered after 3 cycles of reaction (b) Washing with NaOH (2M), 3 times at 60°C (c) Active carbon as hard template. Carbon removal via calcination (air) at 500°C, 1h

Table 1 .

 1

				7+	6+	5+	4+	0+
				Re	Re	Re	Re	Re
		Re4f									Ce3d			Ce	4+ 5/2
															Ce	3+ 5/2
	Intensity (a.u)									Intensity (a.u)
	52	50	48	46		44		42	40	930	920	910	900	890	880	870
			binding energy (eV)				Binding energy (eV)
	Figure 1.5. XPS spectra of the 10 wt.% ReOx/CeO2 -HSA-5 catalyst before (up) and after reaction (down) in Re
	4f and Ce 3d regions. The binding energy zone of Re4f7/2 for the different oxidation states are indicated in the

2, entry 3), which coincidence with a decrease in the catalytic activity (Table

1

.3). colored regions

[24]

[33]

[34]

[35]

. Reference: C 1s = 284.6 eV. Normalized by area of Ce 3d XPS

Table 1 .

 1 2. Summary of XPS data of ReOx/CeO2-HAS-5, ReOx/CeO2+SiO2 and ReOx/CeO2+SBA-15 catalysts, before and after NaOH treatment.

Table 1 .

 1

	Entry	Catalyst	Conversion	Yield
			(%) (b)	(%) (b)
	1	10wt% ReOx/ CeO2 (HSA-5)	>99	84
	2	10wt% ReOx/ CeO2 (HSA-5) (c)	95	77
	3	10wt% ReOx/CeO2+SiO2	>99	86
	4	10wt% ReOx/CeO2+SiO2 (c)	93	72
	5	10wt% ReOx/CeO2+SBA-15	>99	88
	6	10wt% ReOx/CeO2+SBA-15 (c)	91	73
	7	10wt% ReOx/ CeO2 + Carbon (d)	95	80

3

. Influence of ceria synthesis in the performance of DODH of glycerol

(a)

(a) Reaction conditions: Glycerol (1.0 mmol), Catalyst (100 mg), 2-Hexanol (3,33 mL), 175°C (oil bath), 1300 rpm, 2,5 h (b) Conversion and yield on the basis of glycerol, determined by GC analysis with benzene as an internal standard. (c) Washing with NaOH (2M), 3 times at 60°C (d) Active carbon as hard template. Carbon removal via calcination (air) at 500°C, 1h

Table 1 .

 1

4

. Influence of ReOX amount in the performance of DODH of glycerol to allyl alcohol

(a)

Table 1 .

 1 5. Effect of solvent on the performances in DODH reaction of glycerol to allyl alcohol(a)

	1	CeO2+SiO2	3	0
	2	2.5wt% ReOx/CeO2+SiO2	91	77
	3	5wt% ReOx/CeO2+SiO2	>99	84
	4	10wt% ReOx/CeO2+SiO2	>99	86
	5	15wt% ReOx/CeO2+SiO2	>99	81

The influence of the nature of sacrificial alcohol was studied for the 10 wt.% ReOx/ CeO2+SiO2 catalyst. The results are reported in Table

1

.5. High yields in allyl alcohol were observed using Figure 1.8. Hot filtration test. (a) 10 wt.% ReOx/CeO2+SiO2 with 2-hexanol in pressure glass reactor for 1h at 170°C. Catalyst was removed by filtration at high temperature, and the filtrate without 10 wt.% ReOx/CeO2+SiO2 was heated to 175°C (oil bath) for another 24h. (b) Glycerol conversion and yield of allyl alcohol for 24h without removing catalyst were recovered at 1h and 24h for comparison test. (c) Glycerol conversion without catalyst was studied for another comparison test.

Table 2

 2 measured boiling temperatures and reported values from literature was carried out. As given in Table 2.1, close values were noted; the maximum boiling point deviation for Allyl alcohol, 2-hexanol, 2-hexanone, MIBC and MIBK are 0.23 K, 0.27K, 0.58K, 0.1K and 0.17K, respectively.

.1. The masse fraction reported by the manufacturer was confirmed by gas chromatographic analysis (GC) equipped with a flame ionization detector (FID), using the area method. Furthermore, a comparison between

Table 2 .

 2 1. Experimental components information.

	Component	CAS	Suppliers	Mass fraction	This work	Tb [K] a	Lit	Analysis method
	Allyl Alcohol
		107-18-6

Table 2

 2

.2. Numerical data regression was carried out to fit the vapor pressure data with Extended Antoine equation (Eq 2.1) and the corresponding coefficients are presented in Table

2

.3. A maximum average error of 0.004 kPa between experimental and calculated vapor pressures was observed. As showed in Figure

2

.2, vapor pressure data also agree with the values previously reported (NIST database).

Table 2 .

 2 2. Measured vapor pressure data for all components

Pressure (kPa) Temperature (K) Allyl alcohol 2-hexanol 2-hexanone MIBC MIBK 101.32

  𝑇 + 𝐶 5 𝐿𝑛(𝑇) + 𝐶 6 𝑇 𝐶 7 𝑓𝑜𝑟 𝐶 8 ≤ 𝑇 ≤ 𝐶 9

	𝐿𝑛 ( 𝑃 𝑖 𝑠 ⁄ 𝑘𝑃𝑎	) = 𝐶 1 +	𝐶 2 𝑇 + 𝐶 3	+ 𝐶 4 Eq 2.1
			369.98	412.77	400.12	404.75	388.83
	95	368.22	410.51	397.64	402.78	386.61
	90	366.78	408.88	395.78	401.14	384.78
	85	365.27	407.15	393.9	399.45	382.87
	80	363.69	405.28	391.87	397.66	380.88
	75	362.01	403.41	389.82	395.78	378.76
	70	360.26	401.41	387.53	393.82	376.53
	65	358.39	399.28	385	391.73	374.18
	60	356.38	397.16	382.49	389.5	371.68
	55	354.26	394.65	379.79	387.14	368.98
	50	351.96	391.98	376.8	384.6	366.11
	45	349.43	389.21	373.75	381.84	363
	40	346.68	386.15	370.49	378.83	359.58
	35	343.63	382.61	366.59	375.5	356
	30	340.2	378.87	362.37	371.76	351.57
	25	336.23	374.64	357.44	367.48	346.71
	20	331.54	369.48	351.06	362.46	341

a u(T) =0.036K and u(P) =0.004 kPa

Table 2 .

 2 3. Coefficients of the extended Antoine equation

	Component	C1	C2	C3	C4	C5	C6	C7 C8/K C9/K
	Allyl Alcohol	77.91	-7702.23 -10.25 -0.0011	-8.72	1.83E-16	5.78 144.15	545.1
	2-hexanol	109.31 -8191.02 -47.58 -0.0032 -13.65	4.32E-06	2.09	223	585.3
	2-hexanone	100.13 -9625.98	26.73	0.0062	-12.64	5.26E-06	1.82 217.35 587.61
	4-methyl-2-pentanol (MIBC)	66.27	-4160.32 -98.28	0.0095	-8.65	8.07E-16	4.82	183	574.4
	4-methyl-2-pentanone (MIBK) 72.26 -8325.25 36.24 0.0075 -8.52 -1.63E-16 5.82 189.15 574.6

Table 2 .

 2 4 -Table 2.6.

	𝑃𝑦 𝑖 𝜑 𝑖 𝑣 = 𝑃 𝑖 𝑠 𝜑 𝑖 𝑠 𝛾 𝑖 𝑥 𝑖 𝑒𝑥𝑝 ∫ 𝑉 𝑖 𝑃 𝑖 𝑠 𝑙 𝑑𝑝 (𝑖 = 1.2.3. … . 𝑁) 𝑃	Eq 2.2
	𝛾 𝑖 =	𝑦 𝑖 𝑃 𝑥 𝑖 𝑃 𝑖 𝑠	Eq 2.3

Table 2 .

 2 4 to Table2.6), respectively. Positive deviations for all binary systems are evidenced. 𝐺 𝐸 for the six binaries have been correlated by a sixth order polynomial equation and plotted in Figure2.3. The mixtures of Allyl alcohol/2-hexanone and Allyl alcohol/MIBK showed the biggest nonideality from Raoul's law compared to those of the other four mixtures.The largest value of the G E is observed when the mixture have equal mole fraction in allyl alcohol and corresponding ketone. Taking all systems, G E follow the order Allyl alcohol/2-

	hexanone > Allyl alcohol/MIBK > MIBK/MIBC > 2-hexanone/2-Hexanol > Allyl alcohol/2-
	Hexanol > Allyl alcohol/MIBC.
	Eq 2.4

𝐺 𝐸 = 𝑅𝑇 (𝑥 1 𝐿𝑛𝛾 1 + 𝑥 2 𝐿𝑛𝛾 2 )

Table 2 .

 2 4. Isobaric Vapor-liquid equilibrium data for Allyl alcohol/2-hexanol and Allyl alcohol/MIBC systems at 101.32 kPa

		Allyl alcohol (1)/2-hexanol (2)				Allyl alcohol (1)/MIBC (2)
	T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	)	𝐺 𝐸 (𝑎)	T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	) 𝐺 𝐸 (𝑎)
	412.62	0	0		1.0003				404.74	0	0		1.0002
	412.02	0.0060	0.0247	1.0467	1.0003	0.0454		1.789	403.51	0.0181	0.0570	1.0290	0.9999	0.0287		1.537
	410.84	0.0183	0.0727	1.0451	0.9998	0.0443		2.212	402.15	0.0386	0.1170	1.0321	1.0001	0.0315		4.363
	408.62	0.0422	0.1576	1.0482	1.0001	0.0470		7.210	401.9	0.0426	0.1280	1.0309	1.0000	0.0304		4.363
	406.88	0.0622	0.2207	1.0484	1.0004	0.0468		11.236	399.76	0.0768	0.2170	1.0350	1.0003	0.0342		9.584
	404.09	0.0965	0.3158	1.0508	1.0006	0.0490		17.865	398.03	0.1063	0.2850	1.0361	1.0006	0.0349		14.099
	400.69	0.1425	0.4207	1.0510	1.0026	0.0472		30.980	395.82	0.1465	0.3670	1.0374	1.0008	0.0359		19.959
	396.98	0.1989	0.5246	1.0532	1.0033	0.0485		42.636	393.51	0.1917	0.4466	1.0380	1.0017	0.0356		27.801
	394.72	0.2369	0.5826	1.0544	1.0030	0.0499		48.707	390.77	0.2506	0.5340	1.0368	1.0032	0.0329		37.196
	391.78	0.2910	0.6514	1.0542	1.0044	0.0484		60.063	389.45	0.2808	0.5734	1.0371	1.0038	0.0326		42.028
	389.74	0.3320	0.6955	1.0540	1.0051	0.0475		67.466	387.47	0.3295	0.6296	1.0357	1.0053	0.0297		48.698
	386.16	0.4130	0.7657	1.0495	1.0094	0.0390		81.718	385.00	0.3961	0.6947	1.0321	1.0089	0.0227		57.146
	383.2	0.4890	0.8180	1.0460	1.0119	0.0332		89.235	383.93	0.4268	0.7213	1.0310	1.0104	0.0201		60.521
	381.79	0.5290	0.8410	1.0430	1.0147	0.0274		92.511	381.38	0.5058	0.7807	1.0269	1.0170	0.0097		69.022
	379.92	0.5860	0.8691	1.0376	1.0253	0.0119		101.042	380.34	0.5405	0.8035	1.0251	1.0206	0.0044		71.921
	377.70	0.6610	0.9010	1.0303	1.0378	-0.0073	101.523	378.47	0.6076	0.8429	1.0207	1.0285	-0.0076	73.928
	376.8	0.6940	0.9130	1.0264	1.0491	-0.0219	102.564	377.05	0.6639	0.8718	1.0155	1.0371	-0.0210	70.376
	374.29	0.7940	0.9460	1.0163	1.0758	-0.0569	86.846	375.65	0.7228	0.8990	1.0107	1.0482	-0.0365	64.817
	373.00	0.8510	0.9620	1.0101	1.1064	-0.0911	73.310	374.41	0.7772	0.9219	1.0075	1.0608	-0.0516	59.029
	371.87	0.9040	0.9760	1.0051	1.1392	-0.1252	52.905	373.35	0.8257	0.9408	1.0053	1.0737	-0.0658	52.136
	370.79	0.9570	0.9890	1.0008	1.2223	-0.1999	28.998	371.99	0.8919	0.9647	1.0026	1.0924	-0.0858	36.601
	369.91	1	1	1.0003					370.94	0.9459	0.9827	1.0006	1.1180	-0.1109	20.330
									369.89	1	1	1.0010
	Table 2.5. Isobaric Vapor-liquid equilibrium data for Allyl alcohol/2-hexanone and Allyl alcohol/MIBK systems
								at 101.32 kPa
		Allyl alcohol (1)/2-hexanone (2)					Allyl alcohol (1)/MIBK (2)
	T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	) 𝐺 𝐸 (𝑎) T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	) 𝐺 𝐸 (𝑎)
	399.90	0.0000	0.0000		1.0001				388.84	0.0000	0.0000		1.0000
	398.93	0.0120	0.0390	1.2214	1.0004	0.1996		9.205	388.01	0.0152	0.0388	1.3592	0.9997	0.3072	14.079
	397.31	0.0330	0.1020	1.2216	1.0012	0.1990		25.519	387.10	0.0330	0.0807	1.3418	0.9998	0.2942	30.609
	395.65	0.0560	0.1650	1.2267	1.0012	0.2031		41.389	385.17	0.0750	0.1659	1.2943	1.0036	0.2544	72.486
	392.69	0.1010	0.2700	1.2227	1.0037	0.1973		77.191	383.41	0.1190	0.2418	1.2615	1.0092	0.2232	113.854
	390.87	0.1320	0.3320	1.2198	1.0050	0.1937		99.187	381.91	0.1619	0.3142	1.2680	1.0038	0.2336	132.065
	388.70	0.1730	0.4020	1.2095	1.0089	0.1813		130.090	380.47	0.2091	0.3786	1.2429	1.0068	0.2107	160.820
	386.63	0.2170	0.4670	1.1994	1.0125	0.1693		158.190	379.09	0.2596	0.4389	1.2174	1.0130	0.1838	191.138
	384.73	0.2630	0.5250	1.1854	1.0174	0.1528		183.702	377.92	0.3097	0.4955	1.2001	1.0129	0.1696	205.224
	382.45	0.3260	0.5910	1.1628	1.0296	0.1217		218.965	376.85	0.3608	0.5429	1.1719	1.0246	0.1343	228.039
	380.21	0.3990	0.6530	1.1336	1.0527	0.0740		255.730	375.98	0.4070	0.5842	1.1528	1.0324	0.1103	240.064
	378.20	0.4770	0.7100	1.1056	1.0793	0.0240		276.010	375.02	0.4643	0.6263	1.1210	1.0587	0.0572	260.579
	376.40	0.5590	0.7620	1.0786	1.1146	-0.0327	282.111	374.22	0.5177	0.6618	1.0932	1.0915	0.0016	274.909
	375.16	0.6240	0.7990	1.0588	1.1504	-0.0830	275.566	373.47	0.5737	0.7056	1.0805	1.1009	-0.0187	265.246
	374.04	0.6900	0.8350	1.0416	1.1892	-0.1325	254.436	372.84	0.6256	0.7382	1.0605	1.1374	-0.0700	263.402
	373.17	0.7460	0.8640	1.0286	1.2318	-0.1803	229.487	372.30	0.6774	0.7733	1.0463	1.1631	-0.1058	245.714
	372.36	0.8020	0.8930	1.0183	1.2778	-0.2270	195.251	371.79	0.7266	0.8076	1.0378	1.1841	-0.1319	226.037
	371.79	0.8440	0.9150	1.0122	1.3135	-0.2605	163.192	371.42	0.7692	0.8351	1.0274	1.2166	-0.1690	204.015
	371.09	0.8990	0.9440	1.0058	1.3689	-0.3082	113.867	371.05	0.8188	0.8667	1.0154	1.2678	-0.2220	171.138
	370.82	0.9210	0.9560	1.0041	1.3879	-0.3236	91.507	370.69	0.8705	0.9020	1.0072	1.3195	-0.2701	129.796
	370.41	0.9560	0.9750	1.0016	1.4358	-0.3602	53.581	370.15	0.9520	0.9613	1.0012	1.4307	-0.3570	56.280
	369.91	1.0000	1.0000	1.0003					369.90	1.0000	1.0000	1.0006

Table 2 .

 2 6. Isobaric Vapor-liquid equilibrium data for 2-hexanone/2-hexanol and MIBK/MIBC systems at 101.32 kPa

		2-Hexanone (1)/2-hexanol (2)				MIBK (1)/MIBC (2)
	T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	) 𝐺 𝐸 (𝑎)	T(K)	𝒙 𝟏	𝒚 𝟏	𝜸 𝟏	𝜸 𝟐	𝑳𝒏 ( 𝜸 𝟏 𝜸 𝟐	) 𝐺 𝐸 (𝑎)
	412.62	0.0000	0.0000		1.0003			404.75	0.0000	0.0000		0.9999
	412.46	0.0079	0.0129	1.1497	1.0003	0.1392	4.731	404.33	0.0179	0.0311	1.1364	1.0001	0.1278	7.957
	411.87	0.0388	0.0610	1.1268	1.0007	0.1187	18.034	403.89	0.0370	0.0631	1.1299	1.0005	0.1217	16.634
	411.04	0.0851	0.1281	1.1036	1.0023	0.0963	35.890	403	0.0771	0.1273	1.1196	1.0012	0.1118	32.827
	409.92	0.1509	0.2165	1.0843	1.0060	0.0749	58.956	402.19	0.1150	0.1841	1.1088	1.0025	0.1007	47.217
	409.16	0.2010	0.2774	1.0648	1.0105	0.0523	71.399	401.31	0.1575	0.2450	1.1027	1.0034	0.0943	60.894
	407.96	0.2820	0.3722	1.0523	1.0159	0.0352	87.314	400.53	0.1966	0.2980	1.0969	1.0042	0.0883	71.749
	407.03	0.3490	0.4449	1.0428	1.0215	0.0206	96.298	399.7	0.2410	0.3525	1.0821	1.0082	0.0708	83.669
	406.36	0.4010	0.4976	1.0341	1.0273	0.0066	99.789	398.67	0.2964	0.4190	1.0751	1.0104	0.0620	95.377
	405.75	0.4510	0.5449	1.0240	1.0360	-0.0116	101.701	397.88	0.3400	0.4682	1.0699	1.0129	0.0547	103.874
	404.82	0.5256	0.6172	1.0214	1.0403	-0.0183	100.627	397.05	0.3894	0.5193	1.0597	1.0182	0.0400	110.827
	404.20	0.5790	0.6647	1.0161	1.0484	-0.0313	97.920	396.95	0.3970	0.5253	1.0543	1.0216	0.0314	111.866
	403.35	0.6555	0.7313	1.0113	1.0567	-0.0439	88.430	396.25	0.4370	0.5666	1.0530	1.0234	0.0285	117.343
	402.66	0.7189	0.7837	1.0077	1.0670	-0.0571	79.523	396.15	0.4450	0.5724	1.0475	1.0279	0.0190	118.276
	401.92	0.7903	0.8408	1.0043	1.0799	-0.0726	65.153	395.25	0.5050	0.6262	1.0351	1.0394	-0.0042	120.146
	401.53	0.8299	0.8716	1.0025	1.0880	-0.0819	54.774	394.4	0.5586	0.6757	1.0338	1.0418	-0.0077	120.047
	400.79	0.9060	0.9299	1.0006	1.1029	-0.0973	32.491	393.65	0.6120	0.7192	1.0255	1.0536	-0.0271	116.671
	400.37	0.9500	0.9630	1.0002	1.1091	-0.1033	17.998	392.85	0.6700	0.7654	1.0194	1.0647	-0.0435	109.563
	399.89	1.0000	1.0000	1.0004				392.1	0.7258	0.8085	1.0152	1.0742	-0.0566	99.611
	399.89	1.0000	1.0000	1.0003				391.3	0.7874	0.8532	1.0100	1.0929	-0.0789	87.063
	399.89	1.0000	1.0000	1.0003				390.68	0.8380	0.8892	1.0067	1.1070	-0.0950	71.534
	399.89	1.0000	1.0000	1.0003				389.99	0.8968	0.9296	1.0029	1.1320	-0.1211	49.974
	399.89	1.0000	1.0000	1.0003				389.51	0.9387	0.9582	1.0013	1.1515	-0.1397	31.917
	399.89	1.0000	1.0000	1.0003				388.87	1.0000	1.0000	0.9991

  Herington test by Wisniak and Van Ness test were employed.

	∑ 𝑥 𝑖 𝑑𝑀 ̅ 𝑖 𝑖	-(	𝑑𝑀 𝑑𝑃 ) 𝑥,𝑇	𝑑𝑃 + ( 𝑑𝑀 𝑑𝑇 ) 𝑥,𝑇	𝑑𝑇 = 0 , 𝑀 =	𝐺 𝐸 𝑅𝑇 = ∑ 𝑥 𝑖 𝑙𝑛𝛾 𝑖 𝑖	Eq 2.5
			∑ 𝑥 𝑖 𝑑𝑙𝑛𝛾 𝑖 𝑖	-	𝑉 𝐸 𝑅𝑇	𝑑𝑃 +	𝐻 𝐸 𝑅𝑇 2 𝑑𝑇 = 0	Eq. 2.6

Table 2 .

 2 7. Margules parameters obtained by G E /RTX1X2 2 linear regression

	1 0	1 0		, 𝜀 = -( 𝑅𝑇 2 ) ( 𝐻 𝐸 𝜕𝑥 1 𝜕𝑇	) 𝑃	, 𝜀 = -( 𝑉 𝐸 𝑅𝑇	) ( 𝜕𝑥 1 𝜕𝑝	)	𝑇	Eq 2.7
					𝐴 * = ∫ 𝑙𝑛 1 0	𝛾 1 𝛾 2	𝑑𝑥			Eq 2.8
		𝐿𝑛 ( 𝛾 2 𝛾 1	) = 𝑎 𝑛 𝑥 1 𝑛 + 𝑎 𝑛-1 𝑥 1 𝑛-1 + ⋯ + 𝑎 1 𝑥 1 + 𝑎 0	Eq 2.9
		𝐺 𝐸 𝑅𝑇𝑥 1 𝑥 2 2 = 𝐴 21	𝑥 1 𝑥 2	+ 𝐴 12 , 𝑙𝑛𝛾 1 ∞ 𝑥 1 →0	= 𝐴 12 , 𝑙𝑛𝛾 2 ∞ 𝑥 2 →0	= 𝐴 21	Eq 2.10

  and Eq 2.15, where N mean the number of experimental points, 𝑃 𝑖 𝑒𝑥𝑝 and y i exp the experimental pressures and mole fraction in vapor phase, 𝑃 𝑖 𝑐𝑎𝑙 and y i cal the calculated values that obtained by UNIQUAC, NRTL, and WILSON thermodynamic models. As to the Van Ness method, VLE data can be considered thermodynamically consistent if ∆y and ∆𝑃 values are less than 1.

	∆𝑦 =	1 𝑁	𝑁 𝑖=1 ∑ 100 |𝑦 𝑖 𝑒𝑥𝑝 -𝑦 𝑖 𝑐𝑎𝑙 |	Eq 2.14
	∆𝑃 =	1 𝑁	∑ 100 | 𝑃 𝑖 𝑁 𝑒𝑥𝑝 -𝑃 𝑖 𝑐𝑎𝑙 𝑖=1 𝑃 𝑖 𝑒𝑥𝑝	|	Eq 2.15

Table 2 .

 2 8. Results of Herington test and Van Ness Method for thermodynamic consistency check

	System	| ∆𝑯 𝒎 ∆𝑮 𝑬 |		Herington		Wisniak (Modified Herington)	Van Ness	Redlich-Kister total area test
												and Aspen tool
			D	J	|D -J|	D	J d	|D -J|	∆𝑦	∆𝑷 𝑘𝑃𝑎 ⁄	|A*|<	Result
												0.03
	Allyl Alcohol	0.94	12.24	66.21	53.96	12.24	20.86	8.6	0.225 a	0.024 a	0.007	Passed
	(1)/2-hexanol (2)									0.259 b	0.027 b
										0.182 c	0.045 c
	Allyl Alcohol	1.89	24.88	54.04	29.16	24.88	34.09	9.21	0.043 a	0.054 a	0.010	Passed
	(1)/MIBC(2)									0.044 b	0.060 b
										0.042 c	0.053 c
	Allyl Alcohol	0.55	14.46	46.5	32.03	14.46	8.49	5.97	0.069 a	0.035 a	0.024	Passed
	(1)/2-									0.067 b	0.035 b
	hexanone(2)									0.066 c	0.035 c
	Allyl Alcohol	0.51	2.90	29.4	26.46	2.90	4.95	2.04	0.109 a	0.035 a	0.0051	Passed
	(1)/MIBK(2)									0.103 b	0.038 b
										0.106 c	0.043 c
	2-hexanone (1)/2-	0.95	14.07	15.1	0.99	14.07	4.75	9.33	0.237 a	0.034 a	0.0081	Passed
	hexanol (2)									0.238 b	0.021 b
										0.313 c	0.040 c
	MIBK	0.58	0.83	20.6	19.76	0.83	3.98	3.16	0.276 a	0.060 a	0.0006	Passed
	(1)/MIBC(2)									0.279 b	0.060 b
										0.279 c	0.063 c
											∆𝐻 𝑚 ∆𝐺 𝑚 𝐸 experimental ratio.
				∆𝑃 1 0 = | 𝑃 𝑏𝑢𝑏𝑏𝑙𝑒 (𝑥 1 → 1) -𝑝 1 0 𝑝 1 0	|				Eq 2.16
				∆𝑃 2 0 = | 𝑃 𝑏𝑢𝑏𝑏𝑙𝑒 (𝑥 1 → 0) -𝑝 2 0 𝑝 2 0	|				Eq 2.17
				Table 2.9. Pure component consistency test
				System		100∆𝑷 𝟏 𝟎	100∆𝑷 𝟐 𝟎
			Allyl alcohol (1)/ 2-hexanol(2)	0.028		0.025
			Allyl alcohol (1)/ MIBC(2)		0.101		0.023
			Allyl alcohol (1)/ 2-hexanone(2)	0.028		0.011
			Allyl alcohol (1)/ MIBK(2)		0.064		0.002
			2-Hexanone (1)/ 2-hexanol(2)		0.039		0.025
				MIBK (1)/ MIBC(2)		0.088		0.010

a UNIQUAC model, b NRTL model, c WILSON model, d J value corrected with

Table 2 .

 2 3. Concerning the UNIQUAC model, volume (r) and area (q) parameters for each component are given in Table2.10. 10. Structural parameters r and q for UNIQUAC model a

	.
	𝑂𝐹 = ∑ [( 𝑁 𝑖=1	𝑇 𝑖 𝑒𝑥𝑝 -𝑇 𝑖 𝑐𝑎𝑙 𝜎 𝑇	)	2	+ (	𝑃 𝑖 𝑒𝑥𝑝 -𝑃 𝑖 𝑐𝑎𝑙 𝜎 𝑃	)	2	+ (	𝑥 𝑖 𝑒𝑥𝑝 -𝑥 𝑖 𝑐𝑎𝑙 𝜎 𝑥	)	2	+ (	𝑦 𝑖 𝑒𝑥𝑝 -𝑦 𝑖 𝑐𝑎𝑙 𝜎 𝑦	)	2	]	Eq 2.18
		𝑅𝑀𝑆𝐷(𝑇 𝑖 ) = (	∑ (𝑇 𝑖 𝑒𝑥𝑝 -𝑇 𝑖 𝑐𝑎𝑙 𝑁 𝑖=1 𝑁	) 2	)	0.5		Eq 2.19
		𝑅𝑀𝑆𝐷(𝑦 𝑖 ) = (	∑ (𝑦 𝑖 𝑒𝑥𝑝 -𝑦 𝑖 𝑐𝑎𝑙 𝑁 𝑖=1 𝑁	) 2	)	0.5		Eq 2.20

Table 2

 2

	Component	r	q
	Allyl Alcohol	2.550	2.300
	2-Hexanol	4.970	4.084
	2-Hexanone	4.597	3.956
	MIBC	4.802	4.124
	MIBK	4.596	3.952
	a Taken from Aspen database

.11

. For all binary systems, one can observe that RMSD (T) and RMSD (y) values are less than 0.24 K and

Table 2 .

 2 11. Binary interaction coefficients, root-mean-square (RMSD) deviations in the equilibrium temperature and vapor phase mole fraction for all binary systems using NRTL, Wilson and UNIQUAC models.

	Model	aij	aji	bij/K	bji/K	αij RMSD(T/K) RMSD(yi)
	Allyl alcohol (1)/2-hexanol (2)
	UNIQUAC	1.633	-1.355	-706.241	559.315		0.08	0.0035
	NRTL	-5.542	2.735	2562.090 -1337.130 0.3	0.09	0.0039
	Wilson	-1.746	4.433	869.063	-2040.740		0.17	0.0031
	Allyl alcohol (1)/MIBC (2)
	UNIQUAC -0.350	0.566	168.175	-287.860		0.19	0.0006
	NRTL	0.529	-0.999	47.204	200.140	0.3	0.22	0.0007
	Wilson	1.472	-1.330	-438.203	319.939		0.19	0.0006
	Allyl alcohol (1)/2-hexanone (2)
	UNIQUAC -0.771	1.573	355.772	-737.781		0.11	0.0089
	NRTL	2.879	-3.805	-893.591	1390.490 0.3	0.12	0.0086
	Wilson	3.122	-2.030 -1176.060	617.432		0.11	0.0084
	Allyl alcohol (1)/MIBK (2)
	UNIQUAC	0.075	-0.461	0.000	75.230		0.16	0.0016
	NRTL	0.961	0.094	-60.732	-163.638 0.3	0.16	0.0015
	Wilson	0.566	-2.065	-152.915	550.640		0.18	0.0016
	2-hexanone (1)/2-hexanol (2)
	UNIQUAC	4.480	-6.101 -1677.110 2292.310		0.14	0.0033
	NRTL	-15.091 20.676 5899.130 -8057.630 0.3	0.10	0.0033
	Wilson	1.221	0.586	-752.332	-83.526		0.19	0.0042
	MIBK (1)/MIBC (2)
	UNIQUAC	1.437	-1.244	-643.368	547.072		0.23	0.0040
	NRTL	-5.239	4.375	2239.820 -1827.390 0.3	0.23	0.0040
	Wilson	-1.666	1.954	712.607	-893.601		0.24	0.0040

  vapor-liquid equilibrium (VLE) data for Allyl alcohol/2-hexanol, Allyl alcohol/2-hexanone, 2-hexanone/2-hexanol, Allyl alcohol/MIBC, Allyl alcohol/MIBK, and MIBK/MIBC systems were measured at 101.32 kPa. Non azeotrope was formed in these six binary systems and positive deviations from Raoul's law were found in all systems, following Binary and Ternary System with Isobutyl Alcohol, Isobutyl Acetate and Dimethyl Sulfoxide at 101.3 kPa," J. Chem. Eng. Data, vol. 62, no. 6, pp. 1902-1909, 2017. [36] J. M. Resa, M. A. Betolaza, C. González, A. Ruiz, "Isobaric vapor-liquid equilibria of acetone-propyl ether and isopropyl ether-propyl ether systems. Corroboration of no reverse volatility," Fluid Phase Equilib., vol. 110, no. 1-2, pp. 205-217, 1995.

the order Allyl alcohol/2-hexanone > Allyl alcohol/MIBK > MIBK/MIBC > 2-hexanone/2-Hexanol >Allyl alcohol/2-Hexanol > Allyl alcohol/MIBC. Where Allyl alcohol/2-hexanone and Allyl alcohol/MIBK showed the biggest non-ideality compared to those of the other four mixtures. All measured VLE data sets passed the thermodynamic consistency with Herington (Wisniak criterion), Van Ness, pure component consistency and Redlich-Kister total area tests. Furthermore, all systems were successfully fitted by UNIQUAC, NRTL and Wilson thermodynamic models, and the corresponding binary coefficients were correlated. MIBK/MIBC system was compared with existing binary coefficients in Aspen data based (NISTV90 NIST-IG and NISTV90 NIST-RK), using UNIQUAC model. the

Table 3

 3

	𝑘 = 𝐾	𝑘 𝐵 𝑇 ℎ	𝑒	-∆𝐺 # ⁄ 𝑅𝑇	, ∆𝐺 # = ∆𝐻 # -𝑇∆𝑆 #	Eq 3.1
				𝑘 = 𝐴𝑒	-𝐸 𝑎 𝑅𝑇 ⁄	Eq 3.2

.2,

where k is the rate constant, K is the transmission coefficient, h and kB are the Planck and Boltzmann constants, respectively, and ΔG # is the free energy of activation.

Table 3 .

 3 2. DODH model kinetics parameters

	Parameters	Solvent 2-Hexanol MIBC
	Ea(kJ/mol)	79.2	55.9
	ΔH # (kJ/mol)	75.5	52.3
	A	1.14E+06	984.56
	ΔS # (kJ/mol)	-119.1	-199.0
	k150°C (S -1 ) 1.93 *10 -4 1.22 10 -4

Table 3 .

 3 3. Catalytic performance during Hydrogenation of 2-Hexanone Conversion and yield on the basis of 2-Hexanone, determined by GC analysis with benzene as an internal standard. c Commercial catalysts. d Synthesis methodology published in[14].

	Parameter a,b		1 wt.% Pt/ɣ-Al2O3 c 5 wt.% Pd/C c Pt50Pd50/TiO2 d
	Conversion (X2-hexanone)	>99	8	47
	Selectivity (S2-hexanol)	>99	>99	79
	Yield	(Y2-hexanone)	>99	8	36.8
	Carbon Balance	>99	>99	90
	a Reaction conditions: 2-Hexanone (3 wt. % ), Catalyst (50 mg), Solvent: MIBC (2 ml), 175°C (oil bath), Hydrogen
	Pressure = 4 bar, 600 rpm, 6 h.

b

Table 3 .

 3 4. DODH reactor -Modelling parameters, using 2-Hexanol and MIBC as solvents

	Parameter	2-Hexanol Value	MIBC Value
	Conversion (XGLY) [%]	96	96
	𝝉 (total) [min]	24.33	51 .85
	Volume [m 3 ]	1.54	3.31
	k (170°C) [S -1 ] a

Table 3 .

 3 6. Optimal design parameters of extractive distillation column (EDC).

	Parameters	Process 1: 2-hexanol Process 2: MIBC
	Entrainer to feed ratio (ENTFR)	3.87	4.67
	Number of stages (NS)	46	46
	Reflux ratio (RR)	2.726	0.958
	Distillate rate to feed ratio (DRTFR)	0.2835	0.2770
	Feed stage (FS)	18	23
	Entrainer Feed stage (FS)	5	6
	Minimum Number of stages (Nm)	23	23
	Condenser Temperature [°C]	96.76	96.76
	Reboiler Temperature [°C]	184.36	186.62
	Feed Temperature [°C]	106.32	106.86
	Entrainer feed Temperature [°C]	83	80

Table 3 .

 3 7. Final design parameters of MIBK purification column (MPC)

	Parameters	Process 2 a Process 3 b
	Number of stages (NS)	95	95
	Reflux ratio (RR)	72.41	17.66
	Distillate rate to feed ratio (DRTFR)	0.0358	0.1457
	Feed stage (FS)	31	36
	Minimum reflux ratio (Rmin)	48.27	11.77
	Minimum Number of stages (Nmin)	47.5	47.8
	Condenser Temperature [°C]	115.69	115.69
	Reboiler Temperature [°C]	147.48	147.21
	Feed Temperature [°C]	143.55	141.45

a Direct purification of MIBK. b MIBK concentration and further purification

Table 3 .

 3 8. General mass balance of process 1, 2 and 3.

	3.S3-3.S5.
		𝑂𝑃𝑌 𝑃1 =	𝑛 𝐴𝑙𝑙𝑦𝑙 𝑛 𝐺𝑙𝑦 +𝑛 𝐻𝑒𝑥-𝑜𝑙 +𝑛 𝐻 2 +𝑛 𝐸𝑛	* 100%		Eq 3.3
		𝑂𝑃𝑌 𝑃2-𝑃3 =	𝑛 𝐴𝑙𝑙𝑦𝑙 + 𝑛 𝑀𝐼𝐵𝐾 𝑛 𝐺𝑙𝑦 + 𝑛 𝑀𝐼𝐵𝐶 + 𝑛 𝐸𝑛	* 100%		Eq 3.4
		Main streams		Process 1		Process 2	Process 3
				(2-hexanol)		(MIBC)	(MIBC)
		Glycerol [Kg/h]		88.406 (0.960) a		88.407 (0.960) a	87.116 (0.946) a
	Inlet	Solvent [Kg/h]		51.097 (0.5)		145.003 (1.419)	146.973 (1.438)
	streams	Entrainer [Kg/h]		0.01	(1x10 -4 )		0.01	(1x10 -4 )	0.01	(1x10 -4 )
		Hydrogen [Kg/h]		1.349 (0.669)		---		---
		Total inlet flow [Kg/h]	140.862 (2.129)		233.420 (2.379)	234.099 (2.384)
		Allyl alcohol [Kg/h]		55.633 (0.958)		55.651 (0.958)	54.833 (0.944)
		Allyl alcohol purity [wt.%] 0.9999			0.9999		0.9999
		MIBK[Kg/h]		---			84.151 (0.840)	43.280 (0.432)
	Outlet	MIBK purity [Mole fraction] ---			0.9997		0.9999
	streams	Total waste [Kg/h]		85.229 (3.379)		93.618 (2.501)	135.986 (2.90)
		Allyl alcohol loss [Kg/h]	0.123 (2.12x10 -3 ) 0.105 (1.81x10 -3 ) 0.109	(1.88x10 -3 )
		Solvent loss [Kg/h]		21.312 (0.209)		46.892 (0.459)	50.291 (0.492)
		Ketone loss [Kg/h]		29.109 (0.291)		12.023 (0.120)	51.50	(0.514)
		Total outlet flow [Kg/h]	140.826 (3.379)		233.420 (4.299)	234.099 (4.276)
		OPY [%]		45.0			76.6		57.7

a

Values shown in brackets correspond to the flow rate in kmol/h

Table 3 .

 3 9. Energy analysis consumption of process 1, 2 and 3

Process 1 (2-hexanol) Process 2 (MIBC) Process 3 (MIBC) Electricity [kW]

		229.09	205.37	235.67
	HP STEAM [kW]	177.26	193.90	271.78
	LM STEAM [kW]	42.48	45.36	50.09
	MP STEAM [kW]	214.95	850.34	343.40
	Cooling water [kW]	680.83	1296.56	902.39
	Total utilities [kW]	1344.61	2591.52	1803.33
	Input flow energy [kW]	231.69	332.86	332.63
	Output flow energy [kW]	248.75	334.48	334.09
	Carbon footprint [kg/h]	100.8	248.9	146
	Energy savings [kw] a	481.10	486.17	567.50
	Energy savings [%] a	35.78	18.76	31.47
	Net primary energy (NPE) [kW] b	863.51	2105.35	1235.82

a Energy integration using Aspen Energy Analyzer. b NPE=Total utilities -Energy savings

Table 3 .

 3 S1. Binary Interaction parameters of UNIQUAC Activity Coefficient model

	Entry Component i Component j	Aij	Aji	Bij	Bji	Ref.
	1	Allyl Alcohol	2-Hexanol	1,633	-1,355	-706,231	559,305	[15]
	2	Allyl Alcohol 2-Hexanone	-0,771	1,573	355,769	-737,781	[15]
	3	2-Hexanone	2-Hexanol	4,480	-6,101	-1677,109	2292,312	[15]
	4	Allyl Alcohol	MIBC	-0,350	0,566	168,170	-287,855	[15]
	5	Allyl Alcohol	MIBK	0,075	-0,461	0,000	75,228	[15]
	6	MIBK	MIBC	1,437	-1,244	-643,367	547,072	[15]
	7	Allyl Alcohol	Water	2,880	-2,126	-1081,310	616,158 APV90 VLE-IG
	8	Water	2-Hexanol	0,000	0,000	77,028	-559,836 APV90 VLE-IG
	9	2-Hexanone	Water	1,627	-1,740	-909,867	417,504	APV90 LLE-ASPEN
		Water	MIBK	-1,746	2,598	458,550	-1272,333	APV90 VLE-IG
		Water	MIBC	-1,540	1,054	313,102	-549,468 APV90 VLE-IG
		Allyl Alcohol	N-Methyl-2-pyrrolidone	-4,031	1,199	1265,260 -280,810	[18]
		Allyl Alcohol	Glycerol	-0,353	0,259	17,103	-103,125 UNIFAC-DMD
		2-Hexanol	Glycerol	-0,725	0,261	-44,612	-28,743	UNIFAC-DMD
		2-Hexanone	Glycerol	-0,658	0,287	-308,377	-24,758	UNIFAC-DMD
		MIBK	Glycerol	-0,658	0,286	-308,212	-24,777	UNIFAC-DMD
		MIBC	Glycerol	-0,723	0,250	-46,219	-27,544	UNIFAC-DMD
		2-Hexanol	N-Methyl-2-pyrrolidone	-1,143	0,623	453,863	-186,395 UNIFAC-DMD
		2-Hexanone	N-Methyl-2-pyrrolidone	0,239	-0,256	53,223	-100,421 UNIFAC-DMD
		MIBC	N-Methyl-2-pyrrolidone	0,694	-1,423	-97,050	430,853	UNIFAC-DMD
		MIBK	N-Methyl-2-pyrrolidone	0,203	-0,210	64,113	-114,555 UNIFAC-DMD
		Glycerol	N-Methyl-2-pyrrolidone	-5,291	4,397	2878,295	-2335,343	UNIFAC-DMD
		Water	Glycerol	0,976	0,261	-188,494	-45,908	APV90 VLE-IG
		Water	N-Methyl-2-pyrrolidone	0,000	0,000	273,700	130,300 APV90 VLE-IG

Table 3 .

 3 S2. Final design parameters of entrainer recovery column (ERC)

	1,2 1,4 1,6 1,8 2,0 2,2 2,4 2,6
	Parameters	Process 1: 2-hexanol Process 2: MIBC
	Number of stages (NS)	24	23
	Reflux ratio (RR)	1.851	2.249
	Distillate rate to feed ratio (DRTFR)	0.1559	0.1340
	Feed stage (FS)	6	7
	Minimum reflux ratio (Rmin)	0.189	0.173
	Minimum Number of stages (Nmin)	9.21	9.145
	Condenser Temperature [°C]	88.58	88.9
	Reboiler Temperature [°C]	210.05	209.8
	Feed Temperature [°C]	189.3	193.6

Table 3 .

 3 S3. Total flow rates and compositions of main streams for Allyl alcohol production from glycerol via DODH reaction using 2-hexanol (process 1)

		Units	H-OL	GLY	INR	INRC	B-RC	H2	OUTH	INEDC	EN-EDC	ALLYL	INERC	Wasted	B-ERC	EN	INH
	Temp	C	30	30	69,92	124,79	145,25	70	70	106,32	83,26	30	189,34	30	210,05	30	70
	Pressure	bar	1,01	1,01	2,2	1,5	1,22	4	4	1,5	1,5	1,01	1,5	1,01	1,171	1,01	4,1
	Molar	MJ/km
	Enthalpy	ol	-390,3 -666,4 -390,55 -347,20 -354,48	1,30	-379,92	-211,96	-255,68	-169,39	-241,94	-302,85	-229,46	-264,89	-379,10
	Enthalpy												-
	Flow	kW	-54,22 -177,7 -2712,2 -2596,3 -2318,0	0,24	-2484,4	-198,95	-931,00	-45,07	1043,68	-203,69	-835,53	-7,4E-03	-2479,0
	Mole Flows	kmol/h	0,50	0,96	25,00	26,92	23,54	0,67	23,54	3,38	13,11	0,96	15,53	2,42	13,11	0,00	23,54
	2-Hexanol	kmol/h	0,50	0,00	24,00	23,04	22,83	0,00	23,50	0,21	0,00	0,00	0,21	0,21	0,00	0,00	22,83

Table 3 .

 3 S4 Total flow rates and compositions of main streams for Allyl alcohol production from glycerol via DODH reaction using MIBC (process 2)

	1,0E-04	0,00

Table 3 .

 3 S5. Total flow rates and compositions of main streams for Allyl alcohol production from glycerol via DODH reaction using MIBC (process 3)

	3,02	1,16	54,59	59,37	57,69	58,07	1,77	56,39	1221,45	1,11	27,26	33,49	1,73	31,23	1,62E-04

L. R. P. De Andrade Lima and D. Hodouin, Miner. Eng., vol. 18, no. 6, pp. 613-621, 2005.

P. Toson, P. Doshi, and D. Jajcevic, Processes, vol. 7, no. 9, 2019

M. Günther et al., Chem. Eng. J., vol. 101, no.1-3, pp. 373-378, 2004.

Acknowledgements I am indebted to my two supervisors, Dr. Benjamin KATRYNIOK and Dr. Marcia ARAQUE. They made writing this dissertation the most enriching learning experience of my academic life. It would not have been possible without their constant guidance, their knowledge and their support throughout all this time and for being directly responsible for this work. Also, for making of every moment a great memory. I thank them for their trust in me and their unfailing support during all these years. I'd like to thank to the board of examiners for the time spent in reviewing this research work. I'd like to show my gratitude to Dr. Masahiro SADAKANE for the opportunity of work in the laboratory, and his support during my stay at Hiroshima University. To all people in the department of applied chemistry for making of my stay one of the best professional and cultural experiences. This dissertation would not have been possible without the assistance of Dr. Svetlana HEYTE, Dr. Jérémy FAYE, Dr. Robert WOJCIESZAK, Dr. Joelle THURIOT and Ing. Jhoann JEZEQUEL. Who patiently answered my many questions and took the time to help me with the technical challenges.

I thank to the laboratory UCCS, University of Lille and Centrale Lille, for adequate facilities and working conditions as well as for the funding of this research project. To all people in the laboratory for making of my stay one of the best professional experiences.

I thank my colleagues and friends Natalia MEDINA, Paola ARANGO and Negissa EBADIPOUR for their constant help and encouragement to complete this PhD as well as for made my day on many occasions. To Santiago PALENCIA and Sebastian ROA, who made sure I took a necessary break and who were a boost of energy in the nick of time.

Preface

This chapter is based on the manuscript: "Deoxydehydration of glycerol to allyl alcohol catalyzed by ceria-supported rhenium oxide" by Silva Vargas, K., Araque, M., Sadakane, M and Katryniok, B. submitted to the Applied catalyst A journal. Karen Silva Vargas carried out all the experiments detailed and data interpretation, with the exception of XRF which was performed by Joelle Thuriot, TEM/STEM which was carried out by Dr. Ahmmed Addad, and XPS by Dr. Pardis Simon, who also contributed to the interpretation of experimental results.

XPS data treatment was carried out with assistance of Dr. Robert Wojcieszak. The document was review by Dr. Benjamin Katryniok and Dr. Marcia Araque.

The Hard template material (SBA-15) used for ceria support synthesis as well as the corresponding ceria impregnation were prepared with the assistance of Dr. Masahiro Sadakane in the department of applied chemistry at Hiroshima University.

Motivation for this work results from the complex recycling protocol reported for the alumina supported Rhenium oxide catalyst (catalyst developed by UCCS laboratory 1 ) which included the need of a calcination as intermediate-step for its reactivation. Accordingly, to ensure a possible scale up of the process, the following study was performed in order to obtain a more robust heterogeneous rhenium-based catalyst. Considering the high catalytic performance of ceria-supported rhenium oxide in combination with 2-Hexanol and MIBC as reductants, detailed in previous chapter, this chapter aims to study the vapor-liquid equilibrium behaviour of the main binary mixtures resulting from the DODH reaction. The accurate experimental EVL data is important for the correct thermodynamic model adjustment, which will be used in for the development of a product separation system via atmospheric distillation.

Preface

This chapter is based on the following manuscript: "Simulation study of a strategy to produce allyl alcohol via Deoxydehydration of glycerol" by Silva Vargas, K., Katryniok, B and Araque, M. which will be submitted to Energy journal. Karen Silva Vargas carried out all the experiments detailed and data interpretation. Process modelling was carried out through Aspen Plus V11 Software. The document was review by Dr. Benjamin Katryniok and Dr. Marcia Araque.

This work aims to evaluate the technical feasibility of a continuous process for the allyl alcohol synthesis from glycerol including integrated product separation via process modelling using Aspen Plus Software. For that purpose, this chapter is based on the experimental work on ceriasupported rhenium oxide catalyst in combination with 2-Hexanol and MIBC as reductants as well as the corresponding DODH reaction conditions described in the chapter 1, and the binary interaction coefficients of the main mixtures resulting from DODH reaction, obtained in previous chapter. Hence, two different scenarios will be performed, 2-Hexanol and MIBC, respectively.

Thermodynamic Model

Given the nature of the components, accurate binary coefficients of UNIQUAC thermodynamic model (Eq 3.S1) were used (Table 3.S1) for all binary systems, namely Allyl/2-hexanol, Allyl/2-hexanone and 2-hexanone/2-hexanol, Allyl/MIBC, Allyl/MIBK and MIBK/MIBC [15] .

Concerning the binary systems with water and glycerol of each component, binary coefficients were obtained from Aspen Plus data base and were predicted by UNIFAC-DMD thermodynamic model, respectively. Given the production of water during DODH reaction, azeotropic mixtures could be formed with the principal product, corresponding solvent and co-produced ketone as shown in Table 3.1. Among these, Azeotrope formed between Allyl Alcohol and Water is the most challenging for our process due to their stoichiometric ratio (Figure 3.1). Following the DODH reaction, the stoichiometric ratio of 1:2 of Allyl alcohol: water, involve maximum mole fraction of 0.33 between Allyl Alcohol in water (lower than 0.44), and therefore, the product purification is not possibly by means of conventional distillation. Thereby, extractive distillation technique was proposed as strategy for allyl alcohol purification. For this purpose, an external componentcalled entrainer-is feed to the column for the purpose to modify the relative volatility of the original components of the mixtures [16], [17] . Wu et al. [18] have successfully reported the use of N-methyl-2-pyrrolidone (NMP) as suitable entrainer to separate allyl alcohol from its aqueous solution. Thus, binary coefficients of UNIQUAC thermodynamic model for Allyl alcohol/ Nmethyl-2-pyrrolidone mixture were used [18] (Table 3.S1). To improve the reliability of the purification unit, vapor-liquid equilibriums (VLE) of the mixtures 2-hexanol/N-methyl-2pyrrolidone, 2-hexanone/ N-methyl-2-pyrrolidone, MIBC/ N-methyl-2-pyrrolidone, MIBK/ Nmethyl-2-pyrrolidone and N-methyl-2-pyrrolidone/glycerol, were predicted by UNIFAC-DMD thermodynamic model (Table 3.S1).

Once the RR and NS were fixed, the impact of RR and FS in the reductant recovery in the bottoms was studied. A maximum recovery percentage of 99.09% and 87.5% of 2-hexanol and MIBK was obtained in the bottom stream, using a FS of 12 and 3, respectively (Figure 3.13, c and d). Optimal design parameters are summarized in Table 3.5.

Allyl alcohol purification (S3)

The design of the Extractive distillation column (EDC) and an entrainer recovery column (ERC) was performed following algorithm 2 (Figure 3.8). Concerning the EDC column, the sensitivity analysis is presented in Figure 3.14. For both processes, a purity of allyl alcohol of 99.99% was achieved. As observed in Figure 3.14 (a) and (b), a minimum number of stages (Nm) of 23 was obtained for a maximum ENTFR of 19. Hence, the optimal number of stages was fixed to 46 in both cases (2*Nm). Once the NS fixed, the effect of the RR ratio on the entrainer to feed ratio (ENTFR) was studied (Figure 3.14 (b) and (c)). The optimal range of the reflux ratio was constrained for a minimum entrainer to feed ratio, between 1 and 4. The corresponding minimum value was taken , considering the impact of the ENTFR in the energy consumption [19] .

Once the RR and NS were fixed, the effect of the distillate to feed ratio (DTFR) in the ENTFR was evaluated. As shown in Figure 3.14 (e) and (f), complete recovery of a pure allyl alcohol is possible using a distillate to feed ratio of 0.2775, nevertheless, the increase of recovery percentage of 99.8 to 99.9% involve a sharp increase of entrainer requirement, and therefore, energy consumption. Thus, the entrainer to feed ratio parameter was minimized, obtaining optimal values of 3.87 and 4.67, for Process 1 and 2, respectively, with a mole fraction of 0.9999 and a maximum recovery percentage 99.8% of allyl alcohol in the distillate. Optimal design parameters are reported in Table 3.6.

Chapter 4. Conclusion and Outlook

Conclusion

This doctoral thesis describes the development of an allyl alcohol production process via the Deoxydehydration reaction of glycerol, using Ceria-supported rhenium oxide as a catalyst and a secondary alcohol reductant-solvent.

Initially, the DODH reaction was sensed to be performed using a previously developed alumina supported Rhenium catalyst and 2-hexanol as hydrogen donor. However, due to multiples drawbacks, mainly due to its challenging recyclability, a new catalyst had to be developed. Furthermore, it was found that both redox couples Re 7+/ Re 5+ and Re 6+/ Re 4+ are involved in the DODH of glycerol to allyl alcohol.

Having identified that 10 wt. %ReOx/CeO2-HSA-5 as active and reusable catalyst for the DODH reaction of glycerol, using 2-hexanol or MIBC as solvent-reductants. The next step towards the development of an integrated process was the development of a separation strategy for the reaction mixture. Therefore, atmospheric distillation was chosen. Since the latter is based on accurate liquid-vapor equilibrium data, the latter were measured for the six main binary mixtures, resulting from the DODH of glycerol. Chapter 2 details the study of the LVE data, considering the used solvent and the corresponding co-produced ketone. The measured data were successfully correlated with NRTL, UNIQUAC and WILSON thermodynamic models, no azeotrope was found and all data sets were proven thermodynamically consistent.

The possibility of an upscaling of the allyl alcohol synthesis from glycerol in a continuous process including integrated product separation and recovery loop for the sacrificial alcohol,

Annexes Annexe A. DODH reaction in continuous flow

DODH of glycerol was carried out in a 50 mL autoclave (Parr 4597) equipped with a mechanic stirrer. The autoclave was loaded with 30 ml of reductant. The reaction system was stirred and heated to reaction temperature at 3°C/min. Then, a solution of glycerol/reductant ( ̴ 3 wt. % Glycerol) was pumped to the reactor with a flow rate of 0.1 ml min -1 . Outlet flow rate was controlled by a pump, in order to keeping constant the reaction volume and achieving steady state conditions. 2-hexanol and MIBC (sigma Aldrich, 99%) were used as reductants.

Sampling points of 200 µl were collected every 30 min. Glycerol, allyl alcohol and ketone (2hexanone/MIBK) concentrations at reaction time t were determined by gas chromatography, using a GC instrument equipped with a column CP-Wax52CB (30m x 250 µm x 0.25 µm) and a flame ionization detector (FID). Allyl Alcohol is an interesting platform molecule due to its broad range of applications. The Deoxydehydration (DODH) of glycerol seems currently the most competitive method to synthesize allyl alcohol from renewable sources. However, so far, this reaction has been only marginally investigated. The aim of this thesis was to develop an integrated production process of allyl alcohol via DODH of glycerol using a secondary alcohol as solvent-reductant. The catalyst development was carried out using ceria-supported rhenium oxide catalyst. Mesoporous ceria materials were synthetized via a nanocasting process using SiO2 and activated carbon as hard templates, giving excellent yields of up to 86%, using a 2-Hexanol or MIBC as a hydrogen donor and solvent. With respect to the process development, isobaric vapor liquid equilibrium data were determined for main binary systems in order to model the distillation column. The experimental VLE data was successfully fitted using NRTL, UNIQUAC and Wilson thermodynamic model. Finally, the integrated process modelling was carried out based on the experimental results and proposing different scenarios depending on the used solvent.

All the proposed strategies allowed to obtain an allyl alcohol purity of 99.99%. In any scenario, the MIBC process proved to be a feasible strategy from a technical point of view, which could potentially be used as starting point for the development of a large scale DODH process.

Mots-clefs: Deoxydehydration, Biomass Valorization, Process Modelling, Glycerol, Allyl alcohol, Heterogeneous catalysis, Vapor-Liquid equilibrium, Integral Simulation