Juliana Melendrez Ruiz

Quentin Buatois

Stephanie Chambaron

Sandrine Monnery-Patris

Gaëlle Arvisenet

Stéphanie Chambaron

Sandrine Monnery- Patris

French consumers know the benefits of pulses, but do not choose them: An exploratory study combining indirect and direct approaches

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Pulses have been cultivated for the past 11 000 years [START_REF] Fortin | L'encyclopédie visuelle des aliments[END_REF], but have attracted far more attention over the last decade, because of their great potential to increase global food security and enhance environmental sustainability. According to the Food and Agriculture Organization (FAO), pulses are leguminous crops harvested exclusively for dry seed (i.e. dried beans, lentils, and peas), but excluding crops used mainly for oil extraction, e.g. soybeans, and those that are harvested green, e.g. green peas (FAO, 2016). Deep roots allow pulse plants to adapt to unfavorable conditions [START_REF] Iriti | Pulses, Healthy, and Sustainable Food Sources for Feeding the Planet[END_REF], so that they can be cultivated almost everywhere. Pulses are unique in the vegetable kingdom in that they fix nitrogen from the atmosphere, fertilizing the soil, and therefore increasing biodiversity (FAO, 2016;[START_REF] Schneider | Rôle des légumineuses dans l'agriculture françcais[END_REF]. In addition to these positive consequences for the environment, pulses present several advantages from a nutritional point of view. Many national and international authorities now highlight the benefits of regular human consumption of pulses. The United Nations declared 2016 to be the International Year of Pulses, under the slogan "nutritious seeds for a sustainable future" (FAO, 2016).

Besides being a major source of plant-based proteins, pulses are rich in dietary fibers, complex carbohydrates, minerals, and vitamins, an almost ideal basis for a healthy diet [START_REF] Curran | The nutritional value and health benefits of pulses in relation to obesity, diabetes, heart disease and cancer[END_REF][START_REF] Mudryj | Nutritional and health benefits of pulses[END_REF]. Increasing pulse consumption to four times per week or more has been associated with a reduced risk of coronary heart disease [START_REF] Bazzano | Legume Consumption and Risk of Coronary Heart Disease in US Men and Women: NHANES I Epidemiologic Follow-up Study[END_REF]. The high fiber content of pulses may have positive effects on short-term satiety [START_REF] Mccrory | Pulse Consumption, Satiety, and Weight Management[END_REF], and weight loss. Pulse consumption can also present health benefits for specific populations. Frequent consumption of pulses, especially lentils, helps to prevent type 2 diabetes in older adults because of the low glycemic index [START_REF] Becerra-Tomás | Legume consumption is inversely associated with type 2 diabetes incidence in adults: A prospective assessment from the PREDIMED study[END_REF]. Folate, a vitamin present in pulses, reduces the risk of neural illness in newborn babies, while iron, a mineral also present in pulses, is known to prevent anemia in women, children, and babies (FAO, 2016). Despite these benefits, pulse consumption in France has declined, from 7.2 kg in 1920 to 1.7 kg per person per year in 2016, although health authorities recommend eating pulses at least twice a week (ANSES, 2017a;[START_REF] Hcsp | AVIS -Relatif à la révision des repères alimentaires pour les adultes du futur Programme national nutrition santé 2017-2021[END_REF]. Some hypotheses to explain low consumption in France are related to consumer issues, e.g. poor knowledge of pulses, bad memories of pulses at the school canteen; the need to plan ahead for pre-soaking, or the lack of recipe ideas and motivation [START_REF] Lecerf | Le génie des légumineuses[END_REF]. Cultural prejudice against pulses, seen as "the poor man's meal", might also explain low consumption [START_REF] Magrini | Les légumes secs en France [Synthèse des débats -Journée d'échanges organisée par le Réseau action climat et Solagro au Ministère de l'environnement[END_REF][START_REF] Rio | Les légumes secs, aliments de choix à valoriser[END_REF]. Packaging-related issues may lower consumer expectations: pulses are often sold in cans, generally perceived as poor quality food, in comparison with foods in the form of prepared dishes or raw products [START_REF] Champ | Les légumineuses pour l'alimentation humaine: apport nutritionnels et effects santé, usages et perspectives[END_REF]. Finally, other reasons could be related to the food product itself, such as the time required for soaking pulses, except for lentils (12 hours or overnight), and unwanted digestive effects, e.g. flatulence [START_REF] Champ | Les légumineuses pour l'alimentation humaine: apport nutritionnels et effects santé, usages et perspectives[END_REF][START_REF] Lecerf | Le génie des légumineuses[END_REF][START_REF] Magrini | Les légumes secs en France [Synthèse des débats -Journée d'échanges organisée par le Réseau action climat et Solagro au Ministère de l'environnement[END_REF][START_REF] Rio | Les légumes secs, aliments de choix à valoriser[END_REF]. These hypotheses have not yet been experimentally tested, requiring new studies to validate them. No scientific study to date has directly investigated mental representation of pulses among consumers in France.

In a French study, declared consumption of pulses was significantly higher (0.3 times more) in men than in women [START_REF] Credoc | Comportements et consommations alimentaires en France: CCAF 2004[END_REF]. Different consumer profiles in relation to pulses have also been reported in countries other than France. In Finland, frequent consumption of beans was significant in young consumers (25-34 years old), and in consumers with a high level of education [START_REF] Jallinoja | Future of sustainable eating? Examining the potential for expanding bean eating in a meat-eating culture[END_REF]. In Canada, pulse consumption was low among young Canadians (18-34 years old), and people living alone, but higher among consumers with a university education (IPSOS, 2010). Such studies, assessing consumption or willingness to consume specific products, are usually based on direct, declarative methods (web-based surveys, online interviews, or focus groups). One possible limitation of declarative methods is the potential dissociation between what participants think or say about their behavior and what they actually do [START_REF] Köster | The psychology of food choice: some often encountered fallacies[END_REF].

Mental representations of food play an important role in consumer behavior and may affect inference, judgment, and food-product choice [START_REF] Bartels | Connecting cognition and consumer choice[END_REF]. Better knowledge of such mental representations may help to develop strategies to increase pulse consumption in France. A mental representation is an image that an individual has of a product, a person, an idea, or a situation. According to [START_REF] Gallen | Le rôle des représentations mentales dans le processus de choix, une approche pluridisciplinaire appliquée au cas des produits alimentaires[END_REF], representations are defined as cognitive products and individual mental processes that come from the interaction of individuals with their environment, allowing them to code the meaning of the stimuli and store this information in memory. Consumers' mental representations can be investigated through direct (i) or indirect (ii) methods.

(i)

Direct methods are typically questionnaires or surveys that ask people to describe their choices or the reasons for their choice, to gather information about their attitudes and behaviors. In direct methods, the questions focus on the main goal of the study, which generally results in consumers becoming aware of the research objective. Among potential biases linked to surveys and questionnaires [START_REF] Mathers | The NIHR RDS for the East Midlands / Yorkshire & the Humber[END_REF], the best known is social desirability bias, where participants seek to present a positive image of themselves to the researcher. Participants thus tend to "under-report socially undesirable attitudes and behaviors and to over-report more desirable attributes" [START_REF] Latkin | The relationship between social desirability bias and self-reports of health, substance use, and social network factors among urban substance users in Baltimore, Maryland[END_REF]. Answering a questionnaire is a complex cognitive task: it implies understanding the meaning of the questions, accessing information stored in memory, adapting this information to the situation, and then estimating the reliability of the chosen answer in relation to all other possible answers [START_REF] Krosnick | Response strategies for coping with the cognitive demands of attitude measures in surveys[END_REF]. Participants may therefore select the first answer acceptable to them without going through the entire cognitive process. (ii)

In contrast, indirect questioning methods are thought to provide access to "unconsciously latent psychosocial constructs" [START_REF] Antonak | Direct and indirect methods to measure attitudes toward persons with disabilities, with an exegesis of the error-choice test method[END_REF]. In cognitive psychology, indirect tests assess the retention of information without direct reference to the source of information [START_REF] Nicolas | Réflexions autour du concept de mémoire implicite[END_REF][START_REF] Perruchet | L'apprentissage implicite : Un débat théorique[END_REF]. This type of "questioning" reduces the risk of respondents becoming aware of the research objective, and thus reduces the potential bias that could be generated if the goal of the study is known. As a consequence, results obtained by indirect methods are thought to be more reliable. Rather than asking respondents directly about their behaviors and motivations, questions are formulated in terms of other people (i.e., your friend, your family, or your students) or imaginary situations (i.e., at school, at the supermarket, or in a restaurant) [START_REF] Belk | Handbook of qualitative research methods in marketing[END_REF].

The aim of this study was to understand the representation of pulses among French non-vegetarian consumers, using both (i) an indirect approach, with a dish-composition task, based on the use of six scenarios evoking real-life situations, and (ii) a direct method, with an online questionnaire. The direct method was expected to provide access to explicit knowledge and beliefs about food-product characteristics, while the indirect method was thought likely to generate more spontaneous behaviors in relation to food choice. The representations obtained through each approach were hypothesized to be different, yet complementary. Combining these two approaches should therefore provide broader access to consumers' mental representations of pulses. If potential barriers are identified, suitable strategies can then be developed to increase pulse consumption.

Material and methods

Participants

Participants had to be over 18 years old, with no specific or restrictive diet (e.g. vegetarian, or glutenfree), no food allergies, and no severe dislike of any foods. Another condition was that participants had to be in the habit of preparing meals several times a week, for themselves and/or their household, to avoid including people unused to composing dishes. To recruit participants, flyers were posted around the city in public places (university, gyms, libraries, and cultural centers). Those who replied were invited to attend an interview where researchers verified that all the above eligibility criteria were met, thus retaining 120 participants for the study. Table 1 gives an overview of the participants' main characteristics. The median age was 35, and the mean age was 39, whether for men or for women. The conditions of the study were explained, and all participants signed informed consent forms before beginning the study. To ensure participation throughout the study, participants would receive 20€ each for participation only if they had completed both tests.

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All 120 participants performed two tasks. The dish-composition task, which evoked real-life situations by means of scenarios, required participants to compose suitable dishes, using images of food products. One week later, participants were required to complete an online questionnaire, based on the same set of images.

Material

Construction of a set of images common to both tasks

Food images were used for both the dish-composition task and the online survey, to provide identical stimuli throughout both tasks. A set of food images was therefore constructed, taking several criteria into consideration. First, all the food products belonged to the French food repertoire, and were chosen to represent the four main categories of food recommended by the French national health and nutrition program (PNNS) to compose a main dish. Food products were presented in the form of raw ingredients. The MFPE group included only foods of animal origin: meat, fish, poultry, and eggs. The Pulse group was composed of dried beans, lentils, and peas. The Starch group was composed of cereals and potatoes. The Vegetable group was composed of products commonly considered as vegetables by French consumers, whatever their botanic classification (broccoli, carrots, green beans, tomatoes, and zucchini).

All food products were purchased from supermarkets, and then photographed in exactly the same conditions. An equivalent volume of each raw product was presented in the center of a white porcelain plate, on a blue background. Blue, rarely a natural food color, was chosen as the background, to create good contrast with the white plate [START_REF] Charbonnier | Standardized food images: A photographing protocol and image database[END_REF]. All photos were taken on the same day, in the same lighting conditions. During the entire photo shoot, the angle of shooting, the distance between the center of the plate and the camera lens, the position of the plate on the table, and the table itself were maintained constant.

After the photos had been standardized via Photoshop ® (luminosity, color intensity, etc.), all twenty images were printed (9cmx13cm) and plasticized. A pre-test was carried out on a small sample of participants (n=30) to ensure that each image was identifiable, that photo quality was good, and that the amount of food was perceived as similar for each image.

Creation of scenarios for the dish-composition task

The dish-composition task used scenarios to create equal and comparable conditions for all participants. Six scenarios evoking real-life conditions encompassed the diversity of situations in which people make food choices (Table 2). The Everyday scenario was conceived as the control for this study. The Budget scenario evoked the constraints of waiting for payday. The Guest scenario placed participants in a social context. The Vegetarian scenario necessarily included a guest with a vegetarian diet, because participant selection criteria excluded vegetarians. For the no-cooking, out-ofhome context, both the more ordinary Self-service scenario, and the more prestigious Restaurant scenario take into account French consumer food habits: they bring food from home for lunch 34% of the time; they often have lunch at the canteen (24%), or at fast-food eateries, pubs, and restaurants (21%); they eat at a friend or family member's house 18% of the time (ANSES, 2017a). Participants were given the written description for each scenario (Table 2), also presented orally, accompanied by the following instructions: "In this situation, compose a main dish using three images".

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Construction of the online questionnaire

The online questionnaire was used to obtain information about each food product individually. Ten question scripts were created to obtain ratings of different food properties by means of a 5-point ordered category scale (Table 3). 3 here 2.3. Procedure 2.3.1. Indirect approach: Dish-composition task All sessions were individual, lasted about 45 minutes, and took place in the laboratory. Images were placed on a table in front of the participant, in the form of a randomized 5 x 4 rectangle (Figure 1), to avoid any effect of order or position. The experimenter asked the participant to identify each food in the images, before presenting the first scenario and asking the participant to compose a main dish, using only three images, although four food groups were represented. This parameter was used to obtain information about the relative importance of each food group for the participant.

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After putting the cards back on the table, participants were asked to compose another dish for the same scenario, without using the same picture triplet. For each scenario, each participant composed five dishes. Once five dishes had been created, a new scenario was presented, with the same instructions. The order of the scenarios was randomized for each participant so as not to bias the results by an order effect.

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Direct approach: questionnaire

Seven to ten days after the dish-composition task, participants were asked to complete an online selfreported questionnaire. To maintain a constant level of attention throughout the task, participants only evaluated sixteen of the images used in the dish-composition task (Figure 1). To obtain this set of 16 images, one product was excluded from each food group, on the basis of low consumption in France compared to other products in that food group (i.e. sausage, white beans, and gnocchi), while tomato was excluded from the Vegetable group as it may also be used for seasoning or sauce. Both the order of the food images and the order of the questions for each image were randomized.

Analysis 2.4.1. Indirect approach: Dish-composition task

The frequency with which each product was chosen by a participant for all of the scenarios was then converted into a rank. The product most frequently chosen by a participant obtained the highest rank.

A Friedman test on the sum of ranks was used to determine if there were significant differences in product choice. A multiple pairwise comparison using the Nemenyi / Two-tailed test was then used to compare the frequency of choice of products in all scenarios.

The frequency of choice for pulses by each participant in each scenario was also converted into a rank as described above. A Friedman test was used to determine if the pulse chosen was different in relation to the scenario. A Nemenyi / Two-tailed test was performed to compare the choice of pulses across scenarios.

The two variables related to the intrinsic characteristics (age and sex) of the participants were used to construct a contingency table. A Correspondence Analysis (CA) with SPAD (version 5, Coheris, France) was used to visualize relationships between consumer profiles and product choices. The CA method is based on a test of independence between participant characteristics and product choice, according to a chi-square statistic.

Direct approach: questionnaire

For each item in the questionnaire, the answers given by each participant were ranked for each food. The product with the "lowest" score (left side of the scale) was given the lowest rank, while the product with the highest score (right side of the scale) obtained the highest rank. A Friedman test was performed on the sum of ranks and then a Nemenyi / Two-tailed test was used to compare the rank of each product for each question.

Complementarity between the two methods

Due to the difference in the nature of the data obtained by each method (frequencies for the dishcomposition task, and ordinal data for the questionnaire), each dataset was converted into numerical format using the appropriate multivariate analysis. For the dish-composition task results, a Correspondence Analysis (CA) was carried out on the frequency of choice for each product in each scenario. The first three dimensions accounted for 96% of the total variance (respectively, 60, 28 and 8% for axes 1 to 3). In contrast, a Multiple Correspondence Analysis (MCA) was carried out on the questionnaire results. The first three dimensions accounted for 73% of the total variance (respectively 47, 16 and 10% for axes 1 to 3).

A Pearson Principal Component Analysis (PCA) was then performed, using the principal coordinates of the CA and the MCA as active variables. The first three dimensions were used as observations. The correlation matrix thus obtained made it possible to compare the results of the dish-composition task with those of the questionnaire (supplementary table).

The confidence interval was set at 95% for all the analyses. The XLSTAT for Windows (Addinsoft, version 2018-1) was used for both univariate and multivariate analyses.

Results

Dish-composition task

Reliability of the indirect method

Before going into detail about food-product choice, we looked at the choices made by participants during their very first dish-composition (by scenario), and after each of the five repetitions of the dishcomposition task. The frequency of choice for each food group in each scenario, taking into account all the dishes created, is shown in Table 4. These results give an overview of repeatability across the five dishes within the same scenario, but also of the variability of food-product selection between scenarios. The results in Table 4 show that participants' choice of food groups was consistent for each of the successive repetitions of the dish-composition task.

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Global frequency of choice for each food image

The frequency of choice for each food image is presented in Figure 2. The Friedman test showed significant differences across food products (p-value < 0.0001). Overall, the Vegetable group were the most frequently chosen (38%). In this group, the most frequently chosen product was tomatoes, followed by carrots, zucchini, green beans, and broccoli. The MFPE group represented 27% of choices: chicken was the most frequently chosen product, followed by beef, salmon, egg, and sausage. Within the Starch group (25% of choices), rice was the most frequently chosen product, followed by potato, tagliatelli, semolina, and gnocchi. The Pulse group, at only 10%, was chosen significantly less frequently for main-dish composition. Within the Pulse group, lentils were the most frequently chosen product, followed by red beans, red lentils, chickpeas, and white beans.

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Frequency of choices for pulses, in each scenario

As food products from the Pulse group were generally those least often chosen in the dish-composition task, it was important to see if the choice of pulses was the same in each scenario. Figure 3 shows that participants chose Pulse-group products differently for each scenario (p-value < 0.0001). Compared to the Everyday scenario (11%), considered as control, Pulse-group product frequency of choice was significantly higher in the Self-service (16%), Restaurant (23%), and Vegetarian (24%) scenarios. In the Vegetarian scenario, the range of possible choices was lower than in the other scenarios, with participants using only two of the five images from the MFPE group. In order to take this difference into account, the frequency of choice for each product was calculated on the basis of 17 possible choices, excluding those never used in the Vegetarian scenario (Table 4). Even after taking this correction into consideration, the choice of Pulse-group products was still more frequent in the Vegetarian scenario than in the Everyday scenario.

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Influence of participant characteristics on food-choice frequency for pulses

A Correspondence Analysis (CA) was used to study the associations between participant characteristics and food-product choices. Khi 2 test was significant (p-value<0.0001). Participants were separated into four groups, based on age and sex. The CA represented in Figure 4 shows how foodproduct choices vary between participants with different characteristics (age and sex). The distance between the points representing food products approximates the chi-square distance between foodproduct frequency of choice. Axis 1 represents 58% and axis 2 represents 27% of the total variance. Axis 1 distinguishes participants by age and axis 2 by sex; participants under 40 years of age used the images of red beans, chickpeas, and red lentils more often than older participants. In contrast, participants over 40 chose eggs and gnocchi more frequently than younger participants. Men favored MFPE products, especially red meat. Men over 40 chose sausage more often, while women over 40 tended to choose white beans and broccoli more often.

Please insert figure 4 here 3.2 Direct approach: online questionnaire

Scores given to the different food images

Table 5 shows a synthesis of the mean score for the sixteen food products, according to the ten evaluation criteria (question scripts). For each column, the highest score indicates the food most representative of that criterion: e.g. the fanciest, the most representative of men's food habits, the healthiest, the most well-liked, and the most frequently eaten. The results from the Friedman tests showed that there were significant differences across the products for all questions. Compared to other food groups, pulses were rated by participants as the food group most difficult to prepare, best adapted (along with the Vegetable group) for a vegetarian diet, and with the exception of lentils, the least frequently eaten and the least well liked.

If we look closer, participant ratings put pulses in second place, behind vegetables, as products that are relatively good for health and the environment, and behind MFPE products, but still quite rich in proteins. All pulses, except red lentils, were identified as being in the medium price range, neither ordinary nor fancy, and corresponding to a neutral food habit, rather than particularly feminine or masculine. Ratings for red lentils placed them just behind salmon, as the second most fancy product.

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The MCA (Figure 5) reveals the modalities associated with each food product for each question. Axis 1 represents 47% of the total variance, with axis 2 representing 16%. Question scripts and response modalities are both clearly represented and well distributed. Axis 1 is characterized by food considered by participants as very expensive, and "very bad" for the health and for the environment. The products associated with these characteristics are from the MFPE group, which are opposed on this axis to plant products from the other three groups (Pulse, Vegetable, and Starch). The positive part of Axis 2 is characterized by food considered difficult to prepare, "not liked at all", and "never consumed" by participants. All the pulses (except lentils, in a central position) are associated with these negative characteristics. Foods consumed "at least once a day", but also considered very bad for the health are found on the negative part of axis 2. The products corresponding to these characteristics are mostly from the Starch group.

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Complementarity of the two approaches

The correlation matrix (Supplementary table) allows us to visualize the links between the results obtained by each of the two methods. Correlations coefficients greater than 0.997 are significant at α= 5%, and correlations coefficients greater than 0.988 are significant at α= 10%. Food choices in the Everyday scenario were significantly correlated with the consumption frequency declared in the online questionnaire for each food product. They were also correlated with "not adapted to a vegetarian diet", "rich in proteins", "not good" for either health or the environment, and corresponding to "very masculine food habits". Products chosen in the Restaurant scenario were highly correlated with the "very expensive" and "difficult to prepare" modalities. Products chosen in the Guest scenario were significantly correlated with the "very expensive", "corresponding to very masculine habits", "not adapted for a vegetarian diet" and "not good for the environment" modalities. The products chosen in the Budget scenario were correlated with the characteristics "good for health [and] the environment", and "poor in proteins". They tended to be considered "very cheap".

Food choices in the Vegetarian scenario were significantly not "very fancy". In this scenario, consumers tended not to choose products that they considered "not adapted for a vegetarian diet" (coefficient correlation: -0.927), but there was, surprisingly, no significant correlation between the products chosen in the Vegetarian scenario and those considered to be "adapted for a vegetarian diet" (coefficient correlation: 0.668). Products chosen in the Vegetarian scenario also tended to be considered as not "rich in proteins", not "very expensive" and not corresponding to "very masculine food habits". In the Everyday scenario, consumed products were also declared as not adapted to a vegetarian diet in the questionnaire with a significant correlation coefficient of 0.998.

Discussion

One of the main objectives was to understand mental representations of pulses among French nonvegetarian consumers, and to identify potential barriers to pulse consumption. We therefore combined an indirect and a direct method, to determine the specific properties attached to pulses in the minds of consumers. We tried to understand how these properties could influence the consumption of pulses, and to propose levers to increase pulse consumption. Three main results will be discussed: the interest of combining these two methods, how mental representations of pulses can explain low pulse consumption, and why knowledge about pulses does not necessarily result in higher consumption. We then propose strategies to increase pulse consumption in France.

Interest of combining the two methods

To our knowledge, our study was the first to combine an innovative indirect approach with a more classical direct approach, in order to understand mental representations of pulses among French consumers. When it was possible, the same factors were studied by the two methods (consumption, difficulty to cook, product adapted for a vegetarian diet, perception of price). Depending on the parameter studied, the use of the two methods gave complementary or convergent information about consumers' mental representations of pulses.

The two methods obtained similar results, with a high correlation coefficient between the results of the dish-composition task in the Everyday scenario and the declared consumption frequency in the questionnaire. This means that, in the dish-composition task, participants did not make random choices, and that their choices genuinely reflected their declared consumption habits. This is an argument in favor of the reliability of the dish-composition task, and of the use of the Everyday scenario as the control in our study.

In the Restaurant scenario, which was meant to evoke a no-cooking, prestigious context, participants tended to choose products that they considered difficult to prepare, and to exclude those they considered easy to prepare. This result was not found in other scenarios, indicating that this scenario is suitable for the study of participants' mental representations of products they consider difficult to prepare.

These correspondences between the results of the two methods are a good indicator of the reliability of the dish-composition task with evoked scenarios (indirect method). This method was also shown to be repeatable within a given scenario, while producing different results for different scenarios. This exploratory study therefore provides a preliminary validation of the dish-composition task, which produced results comparable to those obtained with the questionnaire (direct method). Further studies will be necessary to confirm the reliability of the indirect method. In particular, reproducibility must still be confirmed, by studying several subsets of consumers from within a given population. This task may also be tested with different food products and new scenarios.

For other results, we did not find the expected correlations between the two methods. For example, the dish-composition task in the Budget scenario, meant to be an indicator of the price of products, was not significantly correlated with the declared price obtained through the questionnaire. Many studies have questioned whether consumers are reliable when asked about food price and its importance in choice. Price is often reminiscent of a purchase situation, which is usually complex. Consumers may take other factors into account when referring to the price of products. In particular, consumer attitudes toward price may be influenced by whether the price is judged acceptable or not, taking into account all available information about the product [START_REF] Grunert | Marketing parameters and their influence on consumer food choice[END_REF]. In our study, the products considered to be expensive were chosen in many scenarios, including the control scenario. Information about price seems to be accessible only for products considered to be cheap. Such products were chosen more often in the Budget scenario than in the control, and less often in the Restaurant scenario. Although products considered unsuitable for a vegetarian diet tended to be chosen less frequently in the Vegetarian scenario, somewhat surprisingly this scenario was not significantly correlated with products considered suitable for vegetarians. As the participants were not themselves vegetarian, we had to include another person in the scenario to create the need to choose food adapted for a vegetarian diet. Our explanation is the following: participants had some knowledge of vegetarian food products, but did not consider them to be fancy (significant correlation coefficient: 0.998), and thus perceived them to be unsuitable for an invited guest. Social norms tend to consider healthy foods less acceptable in social situations [START_REF] Zorbas | Factors perceived to influence healthy eating: a systematic review and meta-ethnographic synthesis of the literature[END_REF]. Participants also used significantly more often in the Guest scenario products judged unsuitable for a vegetarian diet.

The absence of a clear relationship between the results of the two methods for these two examples can be seen as an advantage of the indirect method when accessing representations that are difficult to obtain accurately with direct questioning. The questionnaire provided access to consumer knowledge and beliefs about food, while the dish-composition task provided access to food habits and attitudes towards food. Questionnaire responses are more likely than the dish-composition task to suffer from social desirability bias. For the dish-composition task, participants were not asked to give structured answers; instead, they were asked to make choices visualizing themselves in different scenarios. Consumers were not required to focus their attention on a specific food item, allowing them to answer spontaneously, without speculating on the specific aim of the study. In the Everyday scenario, participants significantly chose products that are not good for health or for the environment, suggesting that social desirability was not a major concern. In contrast, when answering the questionnaire, participants were asked to focus their attention on specific products. By doing so, they may have been tempted to imagine what might be a "suitable" answer, or what answer was expected by the experimenters, and therefore to answer accordingly.

A low global consumption of pulses, evidenced by both methods

The choices observed when people are immerged in an evoked situation are thought to reflect the actual choices they would make in the corresponding real-life situation. The overall use of pulses during the dish-composition task was low, amounting to only 10% of all choices. Pulse images were by far the least chosen: these four images were among the six least used by participants. Thus, the dish-composition task indirectly revealed a low level of pulse consumption among participants, confirmed by the low self-declared consumption frequency of pulses, obtained from the questionnaire. The low consumption revealed by both tasks is in accordance with recent food consumption records in France, which highlighted a very low consumption of pulses (ANSES, 2017b). This shows that, based on pulse consumption, our participant sample is representative of French consumers in general.

Our study thus allowed us to go further than consumption data, by accessing consumers' mental representations of pulses.

How representations of pulses can explain their low consumption

The factor that is the most highly correlated with declared non-consumption of food in our study was dislike. Hence, one of the most obvious reasons that can explain the low consumption of pulses is that they are declared to be least liked, with the exception of lentils, the pulse best appreciated by participants. A Canadian survey (IPSOS, 2010) highlighted that, when asking non-consumers to choose the relative importance of a number of factors regarding why they did not eat pulses, not liking the taste or texture of pulses emerged by far as the most important factor. Interestingly, in the same survey, taste was also the most frequent reason given for eating pulses by the group of "light, moderate, and heavy consumers". Several models are proposed in the literature listing the factors involved in food choices. Among these factors, taste is considered to be one of the main drivers of food choice and intake (Shepherd & Raats, 2006). In a study about the links between attitudes and beliefs toward various types of food, taste was shown to have the highest relationship with attitudes for most products [START_REF] Shepherd | Nutrition knowledge, attitudes and fat intake: application of the theory of reasoned action[END_REF]). Yet the study also highlighted that perception of sensory attributes is not the only factor affecting food choices, despite its high impact on attitudes.

Another interpretation emerged from both methods used in our study. First, in the dish-composition task, participants chose pulses more often with the Restaurant and Self-service scenarios than with the Everyday scenario. The common point of these two scenarios suggests a situation in which participants do not have to prepare their meal themselves. This has to be put into perspective, using the responses to the questionnaire, which showed that participants considered pulses as the products most "difficult to cook". From this result, we can state that the difficulty of cooking pulses is one of the main obstacles to their consumption, as hypothesized by other authors [START_REF] Lecerf | Le génie des légumineuses[END_REF][START_REF] Rio | Les légumes secs, aliments de choix à valoriser[END_REF]. Because of this perceived difficulty, participants seem to avoid eating pulses when they have to prepare them themselves. Our results indicate a negative correlation between difficulty of preparation and consumption frequency, which can be considered as an obstacle to consumption in general. This result is consistent with the IPSOS-REID survey, which indicates that, along with taste, not knowing how to prepare or cook pulses is the second most frequent reason for not eating them (IPSOS, 2010). In our study, "difficult preparation" should be interpreted cautiously, because consumers may mean "technically difficult" and/or "difficult to plan for, in the context of daily duties". Preparing a pulse dish at home involves careful planning, to allow for the necessary soaking period, in addition to the time required for the cooking process. As lentils were the only pulses not considered "difficult to cook", the time required for soaking and cooking is probably the main reason why consumers seek to avoid preparing other pulses. It is widely recognized that there is an increasing demand for convenience in meal preparation, which allows consumers to save time and avoid wasting a lot of physical and mental energy [START_REF] Scholderer | Consumers, food and convenience: The long way from resource constraints to actual consumption patterns[END_REF]. In this context, at-home pulse preparation may represent too much time and effort, and thus be incompatible with the time already taken up by work, social life, and leisure activities.

Along with taste, price and healthiness are often proposed as important determinants of food choice. The argument of price as a driver in food choice is well-known in the literature and concerns many products [START_REF] Darmon | Contribution of food prices and diet cost to socioeconomic disparities in diet quality and health: a systematic review and analysis[END_REF]. In our study, the role of price as a lever of consumption is not clear. The products rated most expensive were declared to be consumed the most, and used the most in the dish-composition task in the Everyday scenario. But there was no correlation between declared price and the food chosen in the Budget scenario. It has been shown that perceived price does not involve the price of the product alone. Attitude towards price is influenced by the relationship between the objective price of the product and some reference price postulated by consumers [START_REF] Grunert | Marketing parameters and their influence on consumer food choice[END_REF][START_REF] Ritson | The economics of food choice: is price importants?[END_REF]. This reference price is integrated with other product information when forming attitudes towards purchase [START_REF] Grunert | Marketing parameters and their influence on consumer food choice[END_REF]. The influence of price may be heterogeneous between food categories, because other characteristics specific to a food type may come first (e.g. safety for meat, and brand for chocolate, according to [START_REF] Ritson | The economics of food choice: is price importants?[END_REF].

Our results also showed that pulses were more often used in the Vegetarian scenario than in the other scenarios. From a methodological point of view, the Vegetarian scenario was deliberately not defined, so that participants could interpret this scenario according to their representations of what a vegetarian diet may be. Consumers tend to use a unique word ("vegetarian") when referring to different types of diets excluding meat and poultry. These diets include the vegan diet (no animal products at all), the lacto-ovo-vegetarian diet (including dairy products and eggs), and the pesco-vegetarian diet (including fish, eggs, and dairy products) [START_REF] Tonstad | Type of Vegetarian Diet, Body Weight, and Prevalence of Type 2 Diabetes[END_REF]. In our study, participants placed in a vegetarian context could thus be expected to exclude beef, chicken, and sausage but might still select salmon and eggs from the MFPE group, depending on their definition of a vegetarian diet. Thus, in the Vegetarian scenario, participants could choose food products either among the four groups (selected egg and salmon from the MFPE group), or only among the three plant-based food groups, or among fewer groups, by choosing two or three products from the same food group. In this scenario, choice of products from the MFPE group was divided by four compared to the Everyday scenario. After correcting the results of the Vegetarian scenario to take into account the total number of products chosen in this scenario, the increase in Pulse choice appears to be the highest compared to other plant products. Pulse choice after correction was multiplied by 1.8 compared to the Everyday scenario, while Starch products were not more frequently chosen and Vegetable products were only multiplied by 1.1. This is consistent with Pulse and Vegetable group products being rated in the questionnaire as the foods best adapted for a vegetarian diet. The congruence between the results of the two methods for Pulse group products indicates that consumers considered pulses as products for vegetarians. This result is coherent with a study in Finland, which identified an association between beans and vegetarianism [START_REF] Jallinoja | Future of sustainable eating? Examining the potential for expanding bean eating in a meat-eating culture[END_REF]. A similar result was also obtained from a Canadian survey (IPSOS, 2010). Pulses may be selected by vegetarian consumers who know the importance of their high protein, fiber, and micronutrient content. This frequent consumption by vegetarians seems to be known by non-vegetarians, who tend to associate pulses with a vegetarian diet. This mental representation of pulses as a "niche product" for vegetarians could represent a barrier to consumption by non-vegetarian consumers, since frequently consumed products were declared as not adapted to a vegetarian diet in the questionnaire.

Knowledge about pulses does not necessarily result in higher consumption

Some studies have found that one of the main barriers for not adopting a plant-based diet is the lack of information [START_REF] Lea | Public views of the benefits and barriers to the consumption of a plant-based diet[END_REF][START_REF] Poquet | Interroger les représentations sociales afin d'identifier des leviers en faveur d'un rééquilibrage entre protéines animales et végétales : approche psychosociale[END_REF]. Adequate knowledge is therefore regarded as a necessary -though not sufficientrequirement for healthy sustainable food choices [START_REF] Frick | Literature review on meal choice and meal offering[END_REF]. In our study, questionnaire results highlighted that pulses were considered as more eco-friendly and healthy products than all the MFPE products, but less so than vegetables. In addition, pulses were evaluated as products with a relatively high protein content, just below all the foods of animal origin. This suggests that our participants have relevant knowledge about pulses; they know about their protein content, and their benefits for health and the environment. Yet it seems that this knowledge was not used during the dish-composition task, or that it may have been accessed, but that taste preferences, habits, and other characteristics were considered to be more important.

The literature on nutrition knowledge and food choice is contradictory. Some researchers have shown that nutrition knowledge is positively correlated with making healthy food choices, while other researchers highlight a very weak relationship between nutrition knowledge and food choice. One study mentioned that much of the literature fails to clarify the influence of specific aspects of nutrition knowledge on relevant dietary outcomes [START_REF] Spronk | Relationship between nutrition knowledge and dietary intake[END_REF]. Merely having nutritional knowledge may not be sufficient to modify food choices. One example in France is the Programme National Nutrition Santé (PNNS), which explicitly formulates simple health recommendations for consumers "Pour votre santé, ne mangez pas trop gras, trop salé, trop sucré" (For your health, do not eat foods that are too fatty, too salty, or too sweet), yet consumer food choices are not always optimal [START_REF] Chambaron | Impact of olfactory and auditory priming on the attraction to foods with high energy density[END_REF].

Perspectives: how to include more pulses in French food habits

As knowledge about the benefits of pulses seems to be insufficient to encourage their consumption, there is a need to find other levers, not based on communication about their protein content and their interest for health and the environment. Our study allowed us to identify such levers.

Out-of-home meals could provide an opportunity to increase daily consumption of pulses in France. We have shown in our study that the Restaurant and Self-service scenarios increase the frequency of pulses being chosen. These two scenarios reflect an authentic food habit among French consumers, with 44% of lunches consumed outside the home for adults aged 18 to 44, compared to only 28% for adults aged 45 to 64 (ANSES, 2017a). More recipes with pulses could be proposed in cafeterias and restaurants, giving consumers the opportunity to get to know or rediscover pulses. By encountering the taste of pulses more often, consumers could come to appreciate them more and more, become more familiar with them, and curious about preparing pulse-based dishes for themselves. It will be necessary to help people to acquire knowledge of how to cook pulses properly, by proposing new recipes with different levels of difficulty, stating the time needed, and taking into consideration the different types of consumers and the type of foods they like.

In our study, participants used pulses similarly in the Guest scenario and the Everyday scenario, which indicates that they do not exclude pulses from a situation of social interaction. This means that pulses do not necessarily have a bad reputation among participants. In all scenarios, younger participants chose red beans, chickpeas and red lentils more frequently, which suggests a "young" product image for these particular pulses, probably linked to the fact that they are imported from other food cultures. Questionnaire results indicate that participants considered red lentils to be more fancy than other pulses, and fancier even than beef. All these results indicate that certain pulses can benefit from a positive image. One strategy to increase consumption could thus be to capitalize on this image in order to create innovative foods targeting specific consumers. For example, new products could be created in small formats, like snacks or ready-to-eat dishes, to encourage red bean and chickpea consumption, for young consumers. These products could be inspired by other cultures, with a variety of recipes containing pulses, from Mexico (red beans) or India (chickpeas). To increase the attractiveness of these new products, it is necessary to work not only on their organoleptic properties, but also to take into account their extrinsic properties to attract young consumers' interest. For example, communication should focus on national brands, local and seasonal products, and use the internet and social media, rather than broadcasting on television / radio (ANSES, 2017a).

One final strategy that can be proposed, based on the results of our study, is not to present pulses as a food for vegetarians only. It is necessary to overcome the perceived gap between non-vegetarians and vegetarians, and to encourage all consumers to increase pulse consumption. The main barrier to this shift is probably that non-vegetarians feel that they lack information on how to compose meals around pulses if they do not refer to a traditional recipe. In France, traditional recipes involving pulses usually contain meat [START_REF] Rio | Les légumes secs, aliments de choix à valoriser[END_REF]. It would therefore be interesting to study how French people associate pulses with other food products. Do they use pulses as a substitute for starches, since French recommendations classified them in the same group for many years? Do they use pulses as a substitute for vegetables, due to their commonly perceived healthiness, as evidenced in our study? Do they use pulses as a substitute for meat, due to their acknowledged high protein content? Answering these questions would give us more information regarding the place that pulses have in French food habits, and thus help us to develop new strategies.

Strengths and limitations

One of the strengths of our study was the use of two distinct, yet complementary methods to identify consumer representations that explained low pulse consumption. Some of the properties attributed to pulses by consumers were detected by both methods, suggesting that they are strong barriers to consumption. The price factor was tested by both approaches, but only the indirect approach revealed a link between this factor and low consumption. Such a result could reflect potential involvement of implicit attitudes, which have been shown to predict actual behaviors [START_REF] Marty | Do hedonic-versus nutrition-based attitudes toward food predict food choices? a cross-sectional study of 6-to 11-year-olds[END_REF]. More research will be necessary to confirm the importance of the barriers identified by the indirect method in our study. Other indirect approaches or implicit methods could be used to test the impact of these factors on pulse choice and consumption.

One of the main limitations to our study is that consumer behavior is not measured in real-life conditions. It is possible that food products chosen in an evoked context might not systematically be chosen in real life. Further studies will be necessary to ensure that scenarios provide a level of immersion sufficient for participants to react as they would in an authentic real-life situation. Another limitation relates to the questionnaire, which contained ten questions for each image. Only sixteen of the twenty food products were therefore presented online, so that participants could maintain an adequate level of attention throughout the task.

Conclusion

By combining an indirect method (a dish-composition task with an evoked situation) with a direct method (an online questionnaire), we identified several reasons to explain the low consumption of pulses in France. Our findings provide new evidence of potential barriers to pulse consumption, linked to taste, perceived difficulty of (lengthy) preparation, and the persistent image of pulses as a food clearly associated with a vegetarian diet.

Participants possessed theoretical knowledge about pulses: they were aware of their environmental and health benefits, as well as their high protein content. Yet this awareness did not lead them to modify their food behavior by increasing their consumption of pulses. Our results showed that participants lacked practical knowledge of pulses. More information is necessary about how to cook pulses, how to associate them with other ingredients to create pulse-based dishes, and on what occasions it is appropriate to serve pulses.

To date, communication campaigns in France have simply told consumers to increase their consumption of pulses. Our study identifies other strategies that could prove effective: familiarity can be increased by focusing on out-of-home meals; trendy innovative products can be developed to fit consumer profiles; communication campaigns clearly presenting pulses as a "food for all" can modify erroneous and limited mental representations. Consumers may thus be encouraged to choose pulses more frequently in their everyday lives, with the resulting benefits for their health and for the environment. about statistical analysis, before and after data collection. Catalina Onofrei and Carmela Chateau are particularly acknowledged for English proofreading. The authors have no conflict of interest to disclose.

  Figure 1.

  Figure 2

Acknowledgment

The authors thank Francine Griffon for her precious logistic and technical help in the preparation of the study and for data collection, Joanna Loglisci for her help in data collection, Jacques Maratray for development of the online questionnaire, and Cedric Serrano for taking the photographs and then standardizing the food images. We thank Claire Chabanet and Dominique Valentin for their advice

Funding

This work was supported by the Carnot Institute Qualiment®.

In an everyday meal at your home, you have to prepare the meal.

Self-service You decide to eat at the self-service cafeteria. All the foods represented in the images are on the menu.

Restaurant

You won a dinner at a four-star restaurant during a competition. The restaurant concept invites you to create a dish from a list of ingredients, in order to test the chef's talents.

Budget

At the end of the month, after you paid most of your bills, you do not have a lot of money left and you have to prepare a cheap meal Vegetarian You invited a friend for a meal, which you have to prepare. You have to remember that your friend is vegetarian.

Guest

You and your partner decided to invite the couple who just moved in next door for a meal at your place. * Participants were given only the text of the scenario (Script, without Title). The "Title" was created merely to identify scenarios in this paper.

Table 3

Question scripts

Response modalities on a 5-point ordered category scale Rate each food according to its level of ordinariness or fanciness

From "very ordinary" to "very fancy"

Taking into consideration your habits, rate each food according to difficulty of preparation From "easy" to "difficult"

Rate each food according to its price (Consider the presentation you consume most often)

From "not expensive" to "very expensive"

Rate each food according to masculine or feminine food habits Rating from "very feminine" to "very masculine"

Rate each food according to its suitability for a vegetarian diet

From "not at all adapted" to "very welladapted"

Rate each food according to its effect on health From "very bad" to "very good"

Rate each food according to your food preferences

From "I do not like it at all" to "I like it very much"

Rate each food according to its impact on the environment

From "very bad" to "very good"

Rate each food according to its protein content From "poor in proteins" to "rich in proteins"

Rate each food according to your frequency of consumption

From "never" to "at least once a day"


Marie Décultot
email: marie.decultot@insa-rouen.fr

Alain Ledoux

Marie-Christine Fournier-Salaün

Lionel Estel

and glycerol from 283.15 K to 373.15 K and up to 6.0 MPa

2

glycerol . Henry's law constant s are calculated for each t emperature and are compar ed bet ween t o one another . The sol ubil ity of CO 2 in t hese sol vent s incr eases in t he following order : gl ycerol < 1,2-pr opanediol < met hanol ≈ et hanol .

Introduct ion

Wit h 34 Gt emitt ed each year in t he at mosphere, car bon dioxide is t he most human emitt ed gr eenhouse gases in t he world. These emissions ar e incr easing due to an economic and demogra phic growth, which impl ies an el evat ion of t he consumpt ion of fossil energy [START_REF]IEA, Ener gy and Cl imat e Change[END_REF]. The el evat ion of t he gl obal temperatur e can r each up t o + 5 °C in 2100 if t hese emissions ar e not l imit ed. Ca pt ur e and st orage of CO 2 have r eceived a l ot of att ent ion as a solut ion t o r educe t hese emissions [START_REF]Car bone Dioxide Ca pt ure and St orage, Int ergov. Panel Cl im. Change[END_REF]. In addit ion, t o face up t o t he rar efact ion of fossil fuel s and in a per spect ive of cir cular economy, t he valor isat ion of CO 2 is developing. In t his new chemistry, CO 2 is no mor e seen as a wast e but as a source of car bon used t o pr oduce value-added chemical s [START_REF] Ol Ajir E | Val or izat ion of gr eenhouse car bon dioxide emissions into value-added pr oduct s by catalyt ic pr ocesses[END_REF]. However , only few exa mpl es ar e devel oped on t he industr ial scal e.

In t his cont ext , our work is focused on t he synthesis of organic car bonat e by associat ing CO 2 wit h alcohol or diol or gl ycerol . The ma in car bonat es t hat could be obta ined ar e dimet hylcar bonat e, diet hylcarbonat e, pr opyl ene carbonat e or glycerol carbonat e. Due t o t heir very l ow t oxicit y, t hey have many pot ent ial a ppl icat ions l ike fuel addit ive, solvent or monomer [START_REF] Huang | Recent advances in dialkyl car bonates synthesis and a ppl icat ions[END_REF]. Curr ently, they ar e pr oduced by using some t oxic and harmful component s l ike phosgene. The synthesis via t he rout e (CO 2 + al cohol ) has been pr oven t o be t he mor e int erest ing concerning t he envir onmental aspect and t he sequestrat ion of CO 2 [START_REF] -S. Mont Eiro | Medeir os, Sustainabil it y metr ics for ecotechnologies assessment , part I: pr el iminary scr eening[END_REF].

Many homogeneous and het erogeneous catalyst s have been t est ed for t his synthesis [START_REF] Cao | Research Pr ogr ess in t he Dir ect Synt hesis of Dimet hyl Car bonat e from CO 2 and Met hanol[END_REF][START_REF] Ta Mura | To mishige, Dir ect conver sion of CO 2 wit h diol s, aminoalcohol s and dia mines t o cycl ic carbonat es, cycl ic carba mat es and cycl ic ur eas using het erogeneous catalysts[END_REF]. Some of t hem give high select ivit y but t he yiel d is st ill l ow because of t he unfavourabl e ther modyna mics of t he react ion. Chemical r eact ions take place at about 373. [START_REF] Kr | Liquid-Va por Equilibr ium of Et hanol --Tol uene Sol ut ions[END_REF] K and pr essur e unt il 6.0 MPa . To st udy the kinet ics of t his r eact ion, it is important t o take int o account the data of phase equil ibr ia in t hese condit ions.

The a im of t his art icl e is t o pr ovide a wide range of sol ubil it y of carbon dioxide in four differ ent sol vent s: met hanol , et hanol , 1,2-pr opanediol and gl ycerol . The exper iment s are per for med by a constant-vol ume met hod at t emperatures bet ween 283. 15 K and 373. 15 K and pr essur es u p t o 6.0 MPa for met hanol , et hanol and 1,2-pr opanediol . This r ange of t emperature is higher t han t he one shown in l it erature data . The sol ubil it y of CO 2 in glycerol is measured wit h the sa me met hod and for pr essur es bel ow 2.0 MPa . Onl y one data set is availabl e in t he l it erature for t his range of pr essure [START_REF] Ost Onen | Measur ement s and model ing of CO2 sol ubil i ty in 1,8-d iazabicyclo-[5.4.0]-undec-7-ene-Gl ycerol sol ut ions[END_REF]. The or iginal it y of this pa per is t o pr esent new r el evant data about CO 2 sol ubil it y int o alcohol s.

Ex per imental

2.1.Mat er ial s.

The source and t he pur ity of all compounds used ar e descr ibed in Tabl e 1. All t he chemical s are used as r eceived. Wat er cont ent s of et hanol , met hanol , 1,2-pr opanediol and gl ycerol wer e det er mined using Metrohm Karl Fischer coulometer 899 t itrator .

Apparatus

Figur e 1 r epr esent s a schemat ic diagram of t he a pparatus used t o measure t he sol ubil it y. The exper iment s wer e carr ied out in a sta inl ess st eel cell from Mettl er -Tol edo wit h a ca pacity of 1.61 L (± 0.01 L). The cell was equipped wit h t wo t emperatur e sensor s, one for t he l iquid in t he vessel (Tr ) and one for t he jacket (Tj). A heat carr ied fl uid c ir culat ed t hrough t he jacket to regulat e t he t emperature in t he vessel wit h an accuracy of ± 0.01 K. The pressur e inside t he cell was al so measur ed by a pr essure gauge wit h an accuracy of ± 0.01 bar . An anchor -t ype agitator was used t o st ir t he sol ut ion at about 300 r pm. Th is kind of r eactor is descr ibed in mor e detai l by Figur e 1. Schemat ic diagram of t he a pparatus: 1. cell , 2. jacket , 3. vacuum connector , 4. event valve, 5. st irrer , 6. l iquid inl et , 7. l iquid outl et , 8. buffer tank, 9. CO 2 gas cylinder Balland et al. [START_REF] Balland | Det er minat ion of Kinet ic and Energet ic Paramet er s of Chemical React ions in a Het erogeneous Liquid/Liquid Syst em[END_REF].

The CO 2 cyl inder was connect ed t o a sta inl ess st eel buffer tank wit h a ca pacit y of 2.12 L (± 0.01 L). The t emperatur e (Tb) and pr essur e (Pb) of t his buffer tank were r ecorded wit h t wo sensor s wit h accuracies of ± 0.01 K and ± 0.01 bar r espect ivel y. A valve controlled t he inject ion of CO 2 fr om t he buffer tank t o t he cell . All t he t emperatures and pr essur es measur ed dur ing t he exper iment s wer e r ecorded cont inuousl y using an acquisit ion syst em.

Ex per imental procedur e.

Befor e each exper iment , an a mount of nitrogen was inject ed in t he cell and t he pr essur e was recorded dur ing 2 hour s to t est the gas l eakage of the a pparatus. Then, t he cell was empt ied wit h a vacuum pump t o 100 Pa . The t emperatur e in t he cell was ma inta ined at 283.15 K and around 800 mL of sol vent wer e inject ed int o t he cell t hrough t he l iquid inl et . The exact weight of t he sol vent inject ed, m s, was measur ed, wit h an accuracy of ± 0.2 g , by a doubl e weighing of t he bottle containing t he solvent : befor e and aft er t he inject ion. The mixt ure was st irred dur ing all the exper iment at around 300 r pm. The cell was empt ied aga in wit h t he vacuum pump t o be sur e that t her e is no inert gas in t he cell . The buffer tank was purged wit h CO 2 three t imes and t hen it was fill ed wit h CO 2 . After few minut es t he pr essur e and t he t emperature in t he buffer tank wer e constant . An a mount of CO 2 was inject ed in t he cell t o obta in a ppr oximat ely 0.1 MPa , t he temperature in t he cell was ma intained at 283.15 K. When t he pr essur e and t emperature wer e stabil ised, t he t emperature was ra ised from 283.15 K u p t o 373.15 K by st ep of 10 K. At each st ep, we consider ed t hat the equil ibr ium was reached when t he pr essure was constant . The stabil isat ion per iod t o reach t his equil ibr ium depended on t he sol vent used: for t he ethanol , met hanol and 1,2-pr opanediol t he stabil isat ion t ime was about 50 minut es. A t otal of 150 minut es was used for t he gl ycerol because t he absor pt ion of CO 2 in glycerol is a very slow pr ocess. At t he end of the exper iment s, t hr ee other st eps at 343. 15 K, 313.15 K and 283. [START_REF] Kr | Liquid-Va por Equilibr ium of Et hanol --Tol uene Sol ut ions[END_REF] K wer e made t o control the r epeatabil it y. Thanks t o t his met hod, we insur ed t hat t here is no leakage, t hat CO 2 did not r eact wit h t he sol vent and t hat t he stabil isat ion t ime was sufficiently long. When t he t emperature in t he cell ca me back t o 283.15 K, t he pr essur e was incr eased by introducing CO 2 aga in. Several inject ions of CO 2 wer e made for each solvent . The t emperature and pr essure in t he cell recorded dur ing all t he exper iment s ar e pl otted in Figur e 2 for t he 1,2pr opanediol .

Result s and discussion

Cal culat ion of t he solubil it y

The CO 2 sol ubil it y in t he sol vent is expr essed using t he mol e fract ion : The mol es of CO 2 a bsor bed in t he sol vent ar e calculat ed by a mass balance:

Eq CO inj CO sol CO n n n 2 2 2 - = Eq 3
is t he a mount of CO 2 at the equil ibr ium in t he gas phase in t he cell .

is calculated by t he differ ence of t he a mount of CO 2 in t he buffer tank before t he inject ion ( ) and aft er t he inject ion ( ):

2 1 2 2 2 CO CO inj CO n n n - = Eq 4
All t he a mount s of CO 2 in t he cell and in t he buffer tank wer e calculated by using t he Peng-Robinson equat ion of state [START_REF] Coquel | Pr opr iét és t her modynamiques-Dét er minat ion pour l es fl uides pur s[END_REF]:

2 2 2 ) ( 2 b vb v a T b v RT P r r CO - + - - = α Eq 5
The Tr r epr esent s the t emperature of t he cell and v is t he molar volume of CO 2 . a and b ar e t wo constants calculated wit h t he following equat ions: α(Tr) is a funct ion of t he t emperatur e inside t he cell and of t he CO 2 acentr ic factor ω which is equal to 0.228:

2 2 )] ) ( 1 ( 1 [ ) ( c r r T T m T - + = α
C T B A P Log S liq + - = ) (

Rel iabil it y of t he a pparatus

The standard uncertainty of t he sol ubil it y for each equil ibr ium was calculated from: Ta bl e 4 t o Tabl e 7 r eport the part ial pr essur e of CO 2 at t he equil ibr ium P CO2 , t he sol ubil it y x and t he est imat ed standard uncertaint ies δ x for t he absor pt ion of CO 2 in ethanol , met hanol , 1,2pr opanediol and gl ycerol . The calculated standard uncertaint ies ar e bel ow 2.0×10 -3 , which repr esent s ma inl y (1-2) % of t he values of sol ubil i ty for each sol vent .

        + + + +         + =         + + +         = 2 2 2 2 2 2 2 2 2 ) ( ) ( ) ( ) ( ) ( ) ( ) ( ) (
δ δ δ δ δ δ δ δ Eq 2 2 2 ) ( ) ( ) ( ) ( 2 2         +         +         = i i i i i i i CO i CO T T V V P P n n δ δ δ
Figur e 3 t o Figur e 6 r epresent t he part ial pr essur e of CO 2 pl ott ed aga inst the sol ubil it y for the four solvent s for each t emperature. As expect ed, the sol ubil it y for each solvent incr eases when the pr essur e incr eases but decr eases when t he t emperature incr eases. In t he t emperature and pr essur e ranges st udied, l inear pl ot s ar e obtained bet ween part ial pr essur e of CO 2 and sol ubil ity.

For et hanol , met hanol , 1,2-pr opanediol and gl ycerol , t he correlat ion coefficient s obtained for each t emperature wer e higher t han 0.997. In our range of t emperatur e and pr essur e, t he sol ubil i t y of CO 2 is pr oport ional t o the pr essur e of t he gas over t he sol vent , according to t he Henry's law:

P CO2 = k Hx Eq 14
The k H r epr esent s t he Henry's law constant . [START_REF] Chyl I Ski | Sol ubil it ies of 1-pr opanol and 1,2-pr opanediol in supercr it ical car bon dioxide. New analyt ical procedur e and measur ement s[END_REF] or the phase equil ibr ia for temperature higher t han 373. 15 K [35]. These results ar e not comparable t o our s.

For gl ycerol , onl y one l iterature r efer ence has been found which is r epr esent ed in Figur e 10 [START_REF] Ost Onen | Measur ement s and model ing of CO2 sol ubil i ty in 1,8-d iazabicyclo-[5.4.0]-undec-7-ene-Gl ycerol sol ut ions[END_REF]. The Henry's law constant s obtained by Ost onen et al. ar e very similar to our r esult s. Some other pa per s st udied t he sol ubil it y of CO 2 in gl ycerol but for higher pr essur es [START_REF] Medina -Gonzal Ez | Phase equil ibr ium of t he CO 2 /gl ycerol syst em: Exper imental data by in sit u FT-IR spectroscopy and t her modyna mic model ing[END_REF][START_REF] Nunes | Sol ubil it y of CO 2 in gl ycerol at high pr essur es[END_REF][START_REF] Sovová | Sol ubil it y of squalane, dinonyl pht halat e and gl ycerol in supercr it ical CO 2[END_REF], wher e t he Henry's law is not a ppl icabl e.

All t he Henry's law constant s for t he four sol vent s ar e r eport ed in Table 8 , T = 373.15 K. P CO2 is t he part ial pr essur e of CO 2 in t he cell at t he equil ibr ium, and x is t he mole fract ion of CO 2 in t he l iquid phase. For each sol vent , t he sol ubil it y of CO 2 incr eases wit h a decr ease of temperature and wit h an incr ease of pr essur e. Henry's law constant was calculated for each temperature and for each sol vent , t he sol ubil ity incr eases in t his order : gl ycerol < 1,2pr opanediol < met hanol , et hanol . These differ ences can be explained by t he differ ent structures of t he sol vent s.

Figur e 2 :

 2 Figur e 2: Evol ut ions of temperatur e ( ) and pr essur e ( )in t he cell dur ing t he exper iment in 1,2-pr opanediol

7 Ω

 7 a =0.457, Ω b =0.07780; Tc = 304.25 K and Pc = 7.382 MPa ar e t he cr it ical t emperature and pr essure of CO 2 .

Figur e 4 .Figur e 5 .Figur e 6 .

 456 Figur e 4. Pr essur e-sol ubil it y diagram for CO 2 and l iquid et hanol at differ ent t emperatures, , T = 283.15 K; , T = 293.15 K; , T = 303.15 K; ▲ , T = 313.15 K; , T = 323.15 K; , T = 333.15 K; ◊, T = 343.15 K; △, T = 353.15 K; +, T = 363.15 K; ×, T = 373.15K. P CO2 is t he part ial pr essur e of CO 2 in t he cell at t he equil ibr ium, and x is t he mol e fract ion of CO 2 in t he l iquid

Tabl e 4 .

 4 Part ial pr essur e of CO 2 (P CO2 ), sol ubil ity (x) and standard uncertaint ies ( x ) of CO 2 in l iquid met hanol from 283.15 K t o 373.15 K at t he equil ibr ium a .

Chemical name CAS Source Volume fraction purity a Mass fraction of water Analysis Method Purification method

	1,2-
		57-55-6	Al f a Aes a r	0.995	0.0028	Ka r l -	-
	pr o pa n ed io l					Fis c h er
	Gl y c e r o l	56-81-5	Appl ic h e m	0.99	0.0028	Ka r l -	-
			Pa r r e a c			Fis c h er
	a The purity was provided by the supplier
	Ca r bo n
		124-38-9	Air Liq u id e	0.999			-
	Dio x id e
			Fis h e r
	Abs o l u t e	64-17-5		> 0.995	0.0003	Ka r l -	-
	e t h a n o l		Sc ien t if ic			Fis c h er
			Fis h e r
	Abs o l u t e	67-56-1		> 0.995	0.0002	Ka r l -	-
	me t h a n o l		Sc ien t if ic			Fis c h er

Table 1 .

 1 Chemical compounds used in this study.

δ

  Eq wher e Pi, Ti and Vi correspond r espect ivel y t o t he pr essur e, t emperature and volume of CO 2 at the equil ibr ium in t he cell for and in t he buffer tank befor e inject ion for .

			Temperature/K				A	B	C	Refer ences
	Met hanol		283.15 -373.15			5.20409	1581.341	-33.5	[14]
	Et hanol		283.15 -343.15			5.37229	1670.409	-40.191	[15]
			343.15 -373.15			5.24677	1598.673	-46.424	[14]
	1,2-pr opanediol	323.15 -373.15			6.07936	2692.187	-17.94	[16]
	And δ ( )	is est imat ed by:
			δ	(	n	s	)	=	δ	s s m M (	)	Eq
	3.3. Result s and discussion

  For et hanol , the compar ison wit h seven art icl es is made in Figur e 8[START_REF] Joung | Measur ement s and correlat ion of high-pr essur e VLE of binary CO 2 -alcohol syst ems (met hanol , et hanol , 2-met hoxyethanol and 2-et hoxyet hanol )[END_REF][START_REF] Gu I | Sol ubil it y of CO 2 in Alcohol s, Gl ycol s, Et her s, and Ket ones at High Pr essur es from[END_REF][START_REF] Kar Iznovi | Ex per imental measurement s and pr edict ions of densit y, viscosit y, and carbon dioxide sol ubil it y in met hanol , et hanol , and 1-pr opanol[END_REF][START_REF] Secuianu | Phase behavior for car bon dioxide+et hanol syst em: Ex per imental measur ement s and model ing wit h a cubic equat ion of stat e[END_REF][START_REF] Dal Mol In | Sol ubil it y of car bon dioxide in binary and t ernary mixt ur es wit h et hanol and water[END_REF][START_REF] Gal Icia -Luna | New Apparatus for t he Fast Det er minat ion of High -Pr essur e Va por -Liquid Equil ibr ia of Mixt ur es and of Accurate Cr it ical Pr essur es[END_REF][START_REF] Fr Iend | Establ ishing benchmarks for t he Second Industr ial Fl uids Simulat ion Chall enge[END_REF].These data are in good agreement wit h our r esults, t his compar ison val idat es our met hod t o measur e solubil it y. It can be seen in Figur e 7 and Figur e 8 t hat Henry's law constant is generally det ermined for t emperatures law constant s in t hese t wo works ar e differ ent as we can see in Figur e 9. Our work is closer t o t he r esults obtained by Gal vao et al.[START_REF] Gal Vão | Met hane and carbon dioxide sol ubil it y in 1,2-pr opyl ene glycol at t emperatures ranging from 303 t o 423 K and pr essur es up t o 12 MPa[END_REF] t han t o t he r esult s from Gui et al.[START_REF] Gu I | Sol ubil it y of CO 2 in Alcohol s, Gl ycol s, Et her s, and Ket ones at High Pr essur es from[END_REF]. Th is differ ence can be expla ined by t he degassing of t he sol vent . Indeed, Gal vao et al. used a met hod to degas t he sol vent before it is used, so t hey did not consider any inert gas. On t he contrary, Gui et al. did not use any degassing met hod but consider ed an a mount of inert gas. This gas could have an impact on t he solubil it y of CO 2 , which could expla in t his difference. In our work, we al so degassed our sol vent by evacuat ing t he cell when t he sol vent was inside. Thanks t o t his met hod, we ensur ed t hat no inert gas int eract ed with t he sol ubil isat ion of CO 2 in t he sol vent . This

	lower t han 353.15 K, so our work pr esent s new values of sol ubil it y for higher t emperatures up t o
	373.15 K.

It r efer s t o t he sl ope of t he l ine P CO2 t o x. All the Henry's law coefficient s ar e r eport ed in Tabl e 8. Co mpar isons of t he Henry's law constants obtained in t his work and in t he l it erature ar e r epresent ed in Figur e 7 and Figur e 8 wher e k H is pl ott ed aga inst t he t emperature for met hanol and et hanol . The sol ubil ity of CO 2 in met hanol is the most st udied alcohol , t he data of el even art icl es ar e pl otted in Figur e 7.

[START_REF] Ohgaki | Isot her mal va por -l iquid equil ibr ium data for binary syst ems containing carbon dioxide at high pr essur es: met hanol -car bon dioxide, n-hexane-carbon dioxide, and benzene-carbon dioxide syst ems[END_REF][START_REF] Hong | Va por -l iquid equil ibr ium st udies for t he carbon dioxidemet hanol syst em[END_REF][START_REF] Chang | Densit ies and P-x -y diagrams for car bon dioxide dissol ut ion in met hanol , et hanol , and acetone mixt ur es[END_REF][START_REF] Joung | Measur ement s and correlat ion of high-pr essur e VLE of binary CO 2 -alcohol syst ems (met hanol , et hanol , 2-met hoxyethanol and 2-et hoxyet hanol )[END_REF][START_REF] Bezanehtak | Va por -Liquid Equil ibr ium for Binary Syst ems of Car bon Dioxide + Met hanol , Hydrogen + Met hanol , and Hydrogen + Car bon Dioxide at High Pr essur es[END_REF][START_REF] Schwinghammer | Det er minat ion and modelling of t he highpr essur e va pour -l iquid equil ibr ium car bon dioxide-met hyl acetat e[END_REF][START_REF] Secuianu | Phase equil ibria exper iment s and calculat ions for car bon dioxide + met hanol binary syst em[END_REF][START_REF] Gu I | Sol ubil it y of CO 2 in Alcohol s, Gl ycol s, Et her s, and Ket ones at High Pr essur es from[END_REF][START_REF] Kar Iznovi | Ex per imental measurement s and pr edict ions of densit y, viscosit y, and carbon dioxide sol ubil it y in met hanol , et hanol , and 1-pr opanol[END_REF][START_REF] Leu | The equil ibr ium phase pr opert ies of (car bon dioxide + met hanol )[END_REF][START_REF] Miyano | Henry's constant s of carbon dioxide in met hanol at 250-500 K[END_REF]

.

Onl y t wo art icl es have been found about t he sol ubil it y of CO 2 in 1,2-pr opanediol

[START_REF] Gu I | Sol ubil it y of CO 2 in Alcohol s, Gl ycol s, Et her s, and Ket ones at High Pr essur es from[END_REF][START_REF] Gal Vão | Met hane and carbon dioxide sol ubil it y in 1,2-pr opyl ene glycol at t emperatures ranging from 303 t o 423 K and pr essur es up t o 12 MPa[END_REF]

. The Henry's differ ence in t he met hodology could explain why our r esult s ar e cl ose t o the r esult s of Gal vao et al. In some ot her works, r esearcher s st udied t he sol ubil it y of 1,2-pr opanediol in supercr it ical car bon dioxide

  and pl otted in Figur e 10. Met hanol and et hanol have a similar behaviour t oward t he sol ubil it y of CO 2 . CO 2 is less sol ubl e in 1,2-pr opanediol and very sl ightly sol ubl e in gl ycerol . These r esults ar e in agreement wit h t he explanat ion given in pr evious st udies[START_REF] Gu I | Sol ubil it y of CO 2 in Alcohol s, Gl ycol s, Et her s, and Ket ones at High Pr essur es from[END_REF][START_REF] Gwinner | CO 2 Ca pt ur e in Fl ue Gas: Semiempir ical Appr oach t o Sel ect a Pot ent ial Physical Sol vent[END_REF] wher e t he sol ubil it y of a gas in a sol vent is divided in t wo ma in st eps: f ir st , t he int eract ions sol vent -sol vent must be broken t o cr eat e cavit ies, and t hen the solut e mol ecul es must fill t hese cavit ies wit h t he int eract ion sol ut esol vent . In our case, we have t wo alcohol s, 1,2-pr opanediol wit h t wo hydroxyl groups and glycerol wit h t hr ee hydroxyl groups. This differ ence in t he structur e of molecul es can explain t he differ ence observed in t he sol ubil it y of CO 2 . Indeed, t he hydroxyl groups can for m int ernal hydrogen bond, so gl ycol which has 3 hydroxyl groups has a bett er int ernal int eract ion t han 1,2pr opanediol . That could explain why it absor bes less CO 2 t han 1,2-pr opanediol . Similarly, t he int ernal int eract ions of 1,2-pr opanediol are stronger t han t he int eract ions bet ween alcohol s.

Figur e 3. Pr essur e-solubil it y diagra m for CO 2 and l iquid met hanol at differ ent t emperatures, , T = 283.15 K; , T = 293.15 K; , T = 303.15 K; ▲ , T = 313.15 K; , T = 323.15 K; , T = 333.15 K; ◊, T = 343.15 K; △, T = 353.15 K; +, T = 363.15 K; ×, T = 373.15 K. P CO2 is t he

part ial pr essur e of CO 2 in t he cell at t he equil ibr ium, and x is t he mol e fraction of CO 2 in t he l iquid phase.

10 -2 P CO2 /Pa x δx 10 -2 P CO2 /Pa

  Ta bl e 8. Henry's law constant s k H for met hanol , et hanol , 1,2-pr opanediol and gl ycerol from 283.[START_REF] Kr | Liquid-Va por Equilibr ium of Et hanol --Tol uene Sol ut ions[END_REF] K t o 373.15 K Miyano et al. (2004)[28]; t his st udy (2019) Figur e 8. Henry's law constant k H of CO 2 in l iquid et hanol ver sus t emperature: Joung et al. Kar iznovi et al. (2013) [26]; +Gal icia -Luna et al. (2000)[31]; ⤬ Fr iend et al. Figur e 9. Henry's law constant k H of CO 2 in l iquid 1,2-pr opanediol ver sus t emperature: calculated from Gal vao et al. (2010)[33] Gu i et al. (2011)[25] t his st udy (2019) Figur e 10. Henry's law constant k H of CO 2 in l iquid gl ycerol ver sus t emperature: Ost onen et al. (2014)[8] t his st udy (2019) Figur e 11. Henry's law constant k H of CO2 in l iquid met hanol ( ▲ ), l iquid et hanol ( ), l iquid 1,2-pr opanediol ( ) and l iquid gl ycerol ( ) ver sus t emperature. The sol ubil it y of CO 2 in met hanol , et hanol and 1,2-pr opanediol was measur ed from 283.15 K to 373.15 K and u p t o 6.0 MPa . In gl ycerol , a t emperature range of 323.15 K t o 373.15 K was st udied up t o 2.0 MPa . The constant -volume met hod used in t his work is val idat ed by compar ison wit h l it erature.

		10	-2 P CO2 /Pa 10 -2 P CO2 /Pa T=283.15 K x x	δx δx	10 10 -2 P CO2 /Pa -2 P CO2 /Pa	x T=293.15 K x x	δx δx Δx
	T=283.15 K 0.0072 0.0439 0.0811 0.1203 0.1616 0.2048 T=303.15 K 0.0067 0.0412 0.0763 0.1135 0.1527 0.1938 T=323.15 K 0.0064 0.0389 0.0722 0.1075 0.1447 0.1838 T=343.15 K 0.0062 0.0372 0.0690 0.1027 0.1384 0.1760 T=363.15 K 1.10 0.79 4.79 8.78 12.74 16.73 20.73 1.12 6.71 12.33 17.98 23.76 29.68 1.42 8.70 16.00 23.48 31.20 39.23 1.67 10.64 19.61 28.90 38.60 48.71 0.0070 0.0002 0.0001 0.0002 0.0003 0.0004 0.0006 0.0008 0.0001 0.0002 0.0004 0.0005 0.0007 0.0010 0.0001 0.0002 0.0004 0.0006 0.0008 0.0011 0.0001 0.0003 0.0005 0.0007 0.0009 0.0013 7.56 0.0474 0.0004 14.22 0.0953 0.0007 21.09 0.1364 0.0009 28.03 0.1810 0.0013 34.19 0.2243 0.0017 T=323.15 K 1.35 0.0067 0.0002 9.43 0.0450 0.0004 17.81 0.0908 0.0007 26.64 0.1302 0.0010 35.65 0.1727 0.0014 43.85 0.2141 0.0019 T=343.15 K 1.57 0.0065 0.0002 11.13 0.0434 0.0005 21.17 0.0878 0.0008 31.87 0.1262 0.0011 42.90 0.1673 0.0015 53.07 0.2075 0.0020 T=363.15 K 20.22 0.0466 0.0010 1.56 0.0033 0.0003 7.66 0.0180 0.0005 13.80 0.0321 0.0008 t his st udy (2019) Tabl e 7. Part ial pr essur e of CO 2 (P CO2 ), sol ubil it y (x) and standard uncertaint ies ( x ) of CO 2 in T=293.15 K 0.94 0.0070 0.0001 5.73 0.0425 0.0002 10.52 0.0786 0.0003 15.30 0.1169 20.15 0.1572 0.0007 25.08 0.1993 0.0009 1.27 0.0065 7.70 0.0400 0.0002 14.17 0.0741 0.0004 20.72 0.1103 0.0006 27.46 0.1485 0.0008 34.43 0.1886 0.0011 T=333.15 K 1.56 0.0063 0.0001 9.69 0.0380 0.0003 17.83 0.0705 0.0004 26.22 0.1049 0.0006 34.93 0.1413 0.0009 44.05 0.1795 0.0012 T=353.15 K 1.79 0.0061 0.0001 11.58 0.0365 0.0003 21.33 0.0678 0.0005 31.52 0.1009 0.0007 42.16 0.1361 0.0010 53.41 0.1730 0.0014 T=373.15 K 1.24 0.0068 0.0002 8.51 0.0461 0.0004 16.03 0.0929 0.0007 23.89 0.1331 0.0010 31.87 0.1765 0.0014 39.05 0.2188 0.0018 T=333.15 K 1.47 0.0066 0.0002 10.29 0.0441 0.0004 19.52 0.0891 0.0008 29.32 0.1279 0.0011 39.37 0.1696 0.0015 48.54 1.66 0.0065 0.0002 11.91 0.0429 0.0005 22.74 34.32 0.1249 0.0011 46.29 0.1657 0.0016 57.38 T=373.15 K 21.24 0.0458 0.0010 0.2056 0.0021 1.64 0.0032 8.03 0.0177 14.48 0.0316 0.0008 (2005)[32]; 0.0005 T/K 0.0003 0.0868 0.0008 29.69 0.0802 0.0015 31.61 0.0779 0.0016 35.74 0.0953 0.0019 38.13 0.0926 T=343.15 K 273.15 293.15 313.15 333.15 353.15 373.15 T=353.15 K 0 0.0019 T/K 100 273.15 293.15 313.15 333.15 353.15 373.15 T=353.15 K 23.87 0.0647 0.0013 25.40 0.0628 0.0013 200 0 0.2103 0.0019 1.19 0.0039 0.0003 1.29 0.0037 0.0003 5.94 0.0206 0.0005 6.40 0.0197 10.66 0.0368 0.0007 11.52 0.0351 0.0007 15.58 0.0532 0.0009 16.84 0.0509 0.0010 20.56 0.0704 0.0012 22.26 0.0672 0.0012 25.51 0.0872 0.0015 27.65 0.0832 0.0015 30.60 0.1038 0.0017 33.24 0.0990 0.0018 T=323.15 K T=333.15 K 1.38 0.0035 0.0003 1.48 0.0034 0.0003 6.84 0.0190 0.0005 7.26 0.0185 0.0005 12.32 0.0338 0.0008 13.08 0.0328 0.0008 18.02 0.0490 0.0010 19.15 0.0476 0.0010 T=343.15 K T=353.15 K 1.97 0.0017 0.0002 2.05 0.0017 0.0002 10.16 0.0085 0.0005 10.56 0.0084 0.0005 21.15 0.0173 0.0009 22.01 0.0172 0.0009 T=363.15 K T=373.15 K 2.12 0.0017 0.0002 2.19 0.0017 0.0002 10.95 0.0085 0.0005 11.32 0.0083 0.0005 22.84 0.0173 0.0009 23.65 0.0173 0.0009 0 273.15 293.15 313.15 333.15 353.15 373.15 393.15 T/K 300 400 200 10 k 400 H /MPa 50 100 150 200 250 300 500 600 700 600 800 1000 10 k H /MPa 10 k 800 1200 H /MPa 1400 0.0005 9.31 0.0089 0.0005 9.76 0.0086 0.0005 19.36 0.0179 0.0009 20.27 0.0175 0.0009 350 1600 0.0001 T=303.15 K T=313.15 K T=303.15 K T=313.15 K 1.80 0.0018 0.0002 1.89 0.0018 0.0002 400 (2011)[25] ; T=313.15 K 15.51 0.1433 0.0008 18.27 0.1402 0.0009 20.44 0.1914 0.0012 24.18 0.1860 0.0012 24.68 0.2369 0.0015 29.36 0.2305 0.0016 16.86 0.0794 0.0011 18.76 0.0744 0.0012 20.86 0.0985 0.0013 23.25 0.0922 24.87 0.1180 0.0016 27.81 0.1101 0.0017 at the equil ibr ium a . T=323.15 K 450 T=333.15 K 0.0014 from 283.15 10 -2 P CO2 /Pa x δx 10 -2 P CO2 /Pa x δx (2001)[21] ; Dal molin et al. (2006)[30] ; Secuianu et al. (2008)[29] ; Gu i et al. 500 K t o 373.15 K 0.0005 T=283.15 K T=293.15 K 0.82 0.0075 0.0002 0.96 0.0072 0.0002 5.67 0.0505 0.0004 6.61 0.0489 0.0004 10.59 0.1010 0.0006 12.39 0.0980 12.84 0.0599 0.0009 14.26 0.0562 0.0009 0.0007 0.98 0.0044 0.0003 1.08 0.0042 0.0003 4.90 0.0232 0.0005 5.44 0.0217 Tabl e 6. Part ial pr essur e of CO 2 (P CO2 ), sol ubil ity (x) and standard uncertaint ies ( x ) of CO 2 in 0.0005 8.81 0.0412 0.0007 9.76 0.0388 l iquid 1,2-pr opanediol 0.0007 4. Conclusions
	1.89 12.47 22.98 34.00 45.61 a Standard uncertaint ies u ar e u(P CO2 ) = 1 Pa and u(T) = 0.01 K 0.0061 0.0001 1.96 0.00610 0.0001 0.0360 0.0003 13.31 0.03558 0.0003 0.0668 0.0005 24.56 0.06617 0.0005 0.0996 0.0007 36.43 0.09855 0.0008 0.1343 0.0010 48.95 0.13295 0.0011 Tabl e 5. Part ial pr essur e of CO 2 (P CO2 ), sol ubil ity (x) and standard uncertaint ies ( x ) of CO 2 in 1.73 0.0065 0.0002 1.78 26.86 0.0615 0.0013 28.25 0.0605 0.0013 T methanol ethanol 1,2-propanediol glycerol 350 0.0066 0.0002 12.62 0.0426 0.0005 13.28 0.0425 0.0005 24.72 0.0840 0.0008 26.12 33.47 0.0763 0.0016 35.22 0.0752 0.0016 40.41 0.0908 0.0019 42.58 0.0897 0.0019 283.15 K 103 (±0.8%) 106 (±0.6%) 212 (±1.6%) 293.15 K 128 (±0.1%) 129 (±0.9%) 300 252 (±1.7%) 0.0838 0.0008 36.64 0.1242 0.0011 38.81 T=363.15 K T=373.15 K 303.15 K 155 (±0.6%) 153 (±0.7%) 293 (±1.4%) 250 0.1239 0.0012 49.51 0.1647 0.0016 52.53 0.1645 0.0016 a Standard uncertaint ies u ar e u(P CO2 ) = 1 Pa and u(T) = 0.01 K 1.72 0.0031 0.0003 1.79 0.0031 0.0003 8.39 0.0175 0.0005 8.73 0.0174 0.0005 15.13 0.0312 0.0008 15.75 0.0311 0.0008 22.21 0.0454 0.0010 23.13 0.0452 313.15 K 185 (±0.4%) 179 (±0.8%) 333 (±1.8%) 323.15 K 216 (±0.5%) 205 (±0.8%) 371 (±2.0%) (±5.1%) 333.15 K 247 (±0.6%) 230 (±0.9%) 407 (±2.1%) (±5.2%) 343.15 K 279 (±0.9%) 254 (±0.9%) 440 (±2.1%) (±5.3%) 150 200 1600 H /MPa 1400 10 k 0.0010 29.57 0.0600 0.0013 30.84 0.0598 353.15 K 310 (±0.8%) 277 (±1.0%) 469 (±2.2%) (±5.4%) 100 1200 0.0013 36.92 0.0746 0.0016 38.53 0.0744 0.0016 44.66 0.0891 0.0020 46.67 0.0890 0.0020 l iquid gl ycerol from 323.15 K t o 373.15 K at t he equil ibr ium a . 363.15 K 341 (±0.6%) 298 (±1.0%) 496 (±2.2%) (±5.3%) 373.15 K 369 (±0.6%) 316 (±1.0%) 519 (±2.2%) (±5.4%) 0 50 273.15 293.15 313.15 333.15 353.15 373.15 T/K 600 800 1000 10 k H /MPa
	Henry's law constant s 10 k H /MPa 400
	200
	0
	303.15	313.15	323.15	333.15	T/K	343.15	353.15	363.15	373.15	383.15

l iquid et hanol from 283.

[START_REF] Kr | Liquid-Va por Equilibr ium of Et hanol --Tol uene Sol ut ions[END_REF]

K t o 373.15 K at t he equil ibr ium a . a Standard uncertaint ies u ar e u(P CO2 ) = 1 Pa and u(T) = 0.01 K a Standard uncertainty u is u(T) = 0.01 K Figur e 7. Henry's law constant k H of CO 2 in l iquid met hanol ver sus t emperature: Ohgaki et al. (1976)[18] ; Hong et al. (1988)[19] ; Chang et al. (1997)[20] ; + Joung et al. (2001)[21] ; ⤬ Bezanehtak et al. (2002)[22] ; Schwinghammer et al. (2006)[23] ; Secuianu et al. (2009)[24] Gu i et al. (2011)[25] ; Kar iznovi et al. (2013)[26] ; ✲ Leu et al. (1991)[27]; -

a Standard uncertaint ies u ar e u(P CO2 ) = 1 Pa and u(T) = 0.01 K

Acknowl edgement s

The author s t hank ADEME and MADNESS pr oject for financial support . The MADNESS pr oject has been funded wit h t he support from t he Eur opean Union wit h the European Regional Devel opment Fund (ERDF) and from t he Regional Council of Nor mandie.