Rainer Schillig
email: rainer.schillig@hs-aalen.de

Timo Stock
email: timo.stock@hs-aalen.de

Egon Müller
email: egon.mueller@mb.tu-chmnitz.de

Energy Value-Stream Mapping a Method to Visualize Waste of Time and Energy

Keywords: Energy Value-Stream Mapping, Energy Efficient Production and Logistics, Lean and Green Production, Toyota Production System

In the industry, the Value-Stream Mapping (VSM) method has been successfully used for years to reduce inventory and lead times. With this method, process steps in a value-stream can easily be divided into value-adding and non value-adding ones. However, the VSM does not provide any information about the energy consumption and, as a consequence; it does not give any hint at how much of the energy used actually serves value-adding purposes. This paper describes how the VSM can be extended to an Energy Value-Stream Mapping (EVSM) method which allows dividing the energy input of the production process in value-adding and non value-adding.

Introduction

While the manufacturing industry is one of the main energy consumers, it is at the same time also the key factor for our prosperity. Considering the continuously rising energy cost and an increasing public awareness of the need for a sustainable economic activity, many branches of industry have declared energy efficiency their strategic business objective [START_REF] Müller | Energy Value-Stream Mapping -A Method to Optimize Value-Streams in Respect of Time and Energy Consumption[END_REF].

In Germany for instance, during the second half of the last century, labour productivity has increased almost fourfold, while energy productivity has not even doubled during the same period of time [START_REF]Naturschutz und Reaktorsicherheit: Umweltwirtschaftsbericht 2011, Umweltbundesamt[END_REF]. In the past, the industry's rationalizing efforts have focused on increasing the degrees of automation while simultaneously cutting down the cycle times.

When in the nineties of the last century the methods of the Toyota Production System (TPS), with its focus on systematical waste reduction came to be known in the Western World, numerous companies tried to adopt them for their own use. Since that time the TPS is considered as a benchmark for creating highly efficient value-streams and often it is also described as a lean production system [START_REF] Womack | The Machine That Changed The World[END_REF].

The Toyota Production System

Taiichi Ohno, who is one of the TPS's architects, described its essence as follows: 'All we are doing is looking at the time line from the moment the customer gives us an order to the moment when we collect the cash. And we are reducing that time line by removing the non value-added wastes' [START_REF] Ohno | Toyota Production System. Beyond Large-Scale Production[END_REF], Figure 1.

3

Value-Stream Mapping and Energy Value-Stream Mapping

Rother and Shook [START_REF] Rother | Learning to See. Value-stream mapping to create value and eliminate muda[END_REF] presented in 1999 a method called Value-Stream Mapping which was apt for practical use. This method made it possible to look at the cycle times of work separately from the non value-adding lead time (waste). In their approach, minimizing the lead time extending inventory (waste) was the focus. This approach may convey the impression that the process sequences within the cycle times (work) is, as a matter of principle, free from waste. However, this is not true. When taking a closer look, one can see almost always that the cycle time, of the manufacturing process itself, is composed of value-adding (t va = time value-adding) and non value-adding (t nva = time non value-adding) amounts of time [START_REF] Schillig | Energiewertstromanalyse. Eine Methode zur Optimierung von Wertströmen in Bezug auf den Zeit-und Energieeinsatz[END_REF].

There are several proposals in order to extend the VSM to an Energy Value-Stream Mapping (EVSM) [START_REF]The Lean and Environment Toolkit[END_REF][START_REF] Erlach | Energiewertstrom. Der Weg zur Energie Effizienz Fabrik[END_REF][START_REF] Reinhart | Energiewertstromdesign. Ein wichtiger Bestandteil zum Erhöhen der Energieproduktivität[END_REF][START_REF] Shahrbabaki | Green and Lean Production Visualization Tools; A Case Study exploring EVSM[END_REF][START_REF] Plehn | From Strategic Goals to focused Eco-efficiency Improvement in Production -Bridging the gap using Environmental Value Stream Mapping[END_REF][12][START_REF] Keskin | Value Stream Maps for Industrial Energy Efficiency[END_REF]. Most of these approaches use a stepped 'energy line' to visualize the energy consumption alongside the process chain. The Environmental Protection Agency (EPA) [START_REF]The Lean and Environment Toolkit[END_REF] introduced EVSM by presenting the energy usage for each production step. Erlach and Westkämper [START_REF] Erlach | Energiewertstrom. Der Weg zur Energie Effizienz Fabrik[END_REF] added two figures: The 'Energy Intensity' to describe the process-related energy consumption and the 'Degree of Effi-ciency' to evaluate the process efficiency in comparison with a benchmark process. Reinhart et al. [START_REF] Reinhart | Energiewertstromdesign. Ein wichtiger Bestandteil zum Erhöhen der Energieproduktivität[END_REF] demonstrated in their approach how different forms of energy like electrical, gas or compressed air could be visualized. [START_REF] Erlach | Energiewertstrom. Der Weg zur Energie Effizienz Fabrik[END_REF][START_REF] Reinhart | Energiewertstromdesign. Ein wichtiger Bestandteil zum Erhöhen der Energieproduktivität[END_REF] formulated guidelines to improve the energy efficiency of the value-stream called Energy Value-Stream Design. Shahrbabaki and Jackson [START_REF] Shahrbabaki | Green and Lean Production Visualization Tools; A Case Study exploring EVSM[END_REF] described in principal that energy in an EVSM should be divided into value-adding and non value-adding portions. They lack to explain how this could be done. Plehn et al. [START_REF] Plehn | From Strategic Goals to focused Eco-efficiency Improvement in Production -Bridging the gap using Environmental Value Stream Mapping[END_REF] extended the representation of the EVSM by an input/output model using the criteria energy, materials, water, waste and emissions. Posselt et al. [12] added the process related energy consumption of peripheral systems.Keskin and Kayakutlu [START_REF] Keskin | Value Stream Maps for Industrial Energy Efficiency[END_REF] showed the link between Lean and energy efficiency and the effect of non value-adding time in terms of energy waste.

However none of these proposals is built on an exclusively dual assessment of the time and energy input only referring to the criteria value-adding or not. If the VSM should be extended to an EVSM regarding the energy consumption of the production processes the cycle times must not be regarded as completely value-adding automatically.

Aalen University of Applied Sciences, in cooperation with Chemnitz University of Technology, has developed a method, called 'Dual Energy Signatures' allowing for appraising the process-related energy consumption using the criteria 'value-adding' and 'non value-adding'. This dualised approach allows extending the proven VSM method to an EVSM, in accordance with the principles of the TPS. The classification of energy into E va (Energy value-adding) and E nva (Energy non value-adding) opens up the possibility to divide the cycle times doubtless into t va and t nva , too.

How to Create a Dual Energy Signatures of a Milling Process

In the Aalen University's milling laboratory experiments were taken on a 3-axis vertical machining centre, Hermle Type C 30 V. The machining process consisted in successively milling three grooves of different widths into a component made from heat-treated steel. Milling was done in full cut, with an infeed of 7.5 mm over a distance of 60 mm and using three HSS end mill cutters with diameters 8, 12, and 16 mm. In parallel, a power measurement was taken [START_REF] Müller | Dual Energy Signatures Enable Energy Value-Stream Mapping[END_REF].

To identify the energy, required for the actual chip removal, the authors suggest: Comparing the energy consumption while processing (the workpiece) to a material with a very low density (air). Therefore the test set-up had a distinctive feature in so far as the first pass took place using an 'air cut', in other words processing without a workpiece, Figure 3 -top. Thereby the production parameters should be maintained.

This made it possible to see what the energy signature of the process looked like without any workpiece contact. The second pass took place with workpiece contact, Figure 3 -center. When both signatures are overlaid one gets the dual energy signature Figure 3 -bottom. In this signature the value-adding elements of the process are clearly distinguishable, with regard to the input of energy as well as with regard to their duration, and can be differentiated unmistakably from the non value-adding elements of the process. The value-adding energy directly required for chip removal is 10 Wh, the valueadding time needed therefore is 25 seconds in total. The non value-adding input of energy is 116 Wh, while the non value-adding input of time is 135 seconds. If it isn't While overlaying processing with & without workpiece one gets the dual energy signature. possible to do an air cut, due to technical limitations, the energy required for the chip removal itself can also be calculated. Appropriate approaches are [START_REF] Denkena | Spanen -Grundlagen[END_REF][START_REF] Schulz | Prozeßführung und Energiebedarf bei spanenden Fertigungsverfahren[END_REF]. Thereby a dual energy signature can be drawn as well.

Dual Resolution of cycle time and energy input

The value-adding efficiency of the process in terms of energy, as well as in terms of time, can now be defined as η Eva and η tva , equation 1, 2. Therefore the value adding energy is divided by the total energy consumption of the process [START_REF] Müller | Energy Value-Stream Mapping -A Method to Optimize Value-Streams in Respect of Time and Energy Consumption[END_REF][START_REF] Schillig | Energiewertstromanalyse. Eine Methode zur Optimierung von Wertströmen in Bezug auf den Zeit-und Energieeinsatz[END_REF][START_REF] Müller | Dual Energy Signatures Enable Energy Value-Stream Mapping[END_REF]. The use of dual signatures allows evaluating the production process in respect to the efficient usage of time and energy. The cycle time itself as well as the energy used within this cycle time is thereby consequently subdivided into value-adding and non value-adding parts. In the data box of the milling process the results are shown nominally, in form of figures, as well as proportionally in form of the bars beneath, Figure 5. Fig. 5. Dual signature and data box according to [START_REF] Schillig | Energiewertstromanalyse. Eine Methode zur Optimierung von Wertströmen in Bezug auf den Zeit-und Energieeinsatz[END_REF][START_REF] Müller | Dual Energy Signatures Enable Energy Value-Stream Mapping[END_REF] The low efficiencies show that the dual approach can help to reveal substantial improvement potentials within the production process itself. To increase the process efficiency, basically two approaches are possible: One is to decrease the power level and thereby reducing the non value-adding energy (E nva ). This affects just the energy productivity. The other one is the reduction of non value-adding time (t nva ). That will lead to an increase in productivity and in addition to energy savings. When time is wasted and during this time energy is consumed, this amount of energy necessarily also has to be regarded as waste, too. Up to now the authors have analysed several production processes like milling, casting, welding, injection moulding, handling, robotic and laser applications [START_REF] Müller | Energy Value-Stream Mapping -A Method to Optimize Value-Streams in Respect of Time and Energy Consumption[END_REF][START_REF] Schillig | Energiewertstromanalyse. Eine Methode zur Optimierung von Wertströmen in Bezug auf den Zeit-und Energieeinsatz[END_REF][START_REF] Müller | Improvement of injection moulding processes by using dual Energy Signatures[END_REF][START_REF] Müller | A method to generate Energy Value-Streams in productions and logistics in respect of time-and energy-consumption[END_REF]. For all of them a dualistic approach can be made. Other production processes are actually under research.

) E + E ( E =

Energy Value-Stream Mapping

The analysis of the manufacturing process by means of dual energy signatures allows it to extend the VSM to an EVSM while maintaining the inner logic of the VSM [START_REF] Müller | Energy Value-Stream Mapping -A Method to Optimize Value-Streams in Respect of Time and Energy Consumption[END_REF]. The results of the investigated milling process are embedded into the EVSM, Figure 6. A drilling process and the time and energy used for the transport between the production processes are added (assumed figures). Transport requires almost always energy, has a lead time extending effect and is not value-adding. Consequently the time (t T = time Transport) and energy (E T = Energy Transport) used for transport are considered as non value-adding. This is schematically shown by the rectangular function, Figure 6. As mentioned earlier, only t va serves value-adding purposes, t nva and t T do not. On the right hand side of the time line the sums of these times are visualized. The same logic can be applied to the use of energy in EVSM. When optimizing energy valuestreams it is important to look at the value-stream as a whole, this helps to avoid sub optimisations.

If there are processes which consume lots of resources (time, energy) or entail low value-adding efficiencies they should be seriously questioned in total. Only if it is impossible to find a more efficient manufacturing technology and a more suitable process, then as a second step the time and energy input which does not contribute to adding value can be reduced systematically.

Process Improvement by Dual Energy Signatures and Detailed Process Analysis

Electric energy (E) is the integral of power (P) over time (t). To increase the process efficiency, basically two approaches are possible: Reducing the process time or decreasing the power level [START_REF] Müller | Improvement of injection moulding processes by using dual Energy Signatures[END_REF]. However this requires detailed process knowledge and an analysis of all major components to allocate waste of energy.

Figure 7 shows the principal approach to improve the process efficiency by dual energy signatures and detailed process analysis. Like in figure 4, the value-adding time and energy, required for chip removal, are marked. From the point of view of energy only shares of the spindle and axle drive serves value-adding purposes. They drive the chip removal. As shown in figure 7 all the other components do not serve value-adding purposes. Especially the energy consumption outside the value-adding time should be questionedeliminated. Therefore stop and go systems for the different components should be installed, e.g. for lightning, control cabinet cooling, etc. If complete elimination of the energy consumption in non-value adding periods of time is not possible it should be at least reduced to a minimum.

Fig. 7. Detailed Process Analysis

This mythological approach provides a systematic to identify and question any kind of wasted time and energy.

Summary

Value-streams that include time and energy data are becoming more and more important in the manufacturing industry. With the help of dual energy signatures the value-adding and the non value-adding inputs of time and energy within a production process can be determined, as desired by Ohno. This is shown by using the example of a milling process, in which the energy requirement during air cutting is contrasted with the energy requirement for a milling process with workpiece contact. This distinction makes it possible to extend a VSM to an EVSM. Including transport in the EVSM offers the opportunity of visualizing not only its non value-adding energy requirement but also its lead time-extending effect. This methodical procedure provides a practical tool to process designers for a comprehensive analysis and improvement of value-streams.

Fig. 1 .

 1 Fig. 1.Essence of the TPS according to[START_REF] Ohno | Toyota Production System. Beyond Large-Scale Production[END_REF]

Fig. 2 .

 2 Fig. 2.Value-adding and non value-adding activities according to[START_REF] Ohno | Toyota Production System. Beyond Large-Scale Production[END_REF]

Fig. 3 .

 3 Fig. 3. Milling -air cutting vs. workpiece contact [according to 6]

Fig. 4 .

 4 Fig. 4. Dual energy and time signature of a chip removal process [according to 6, 14]

Fig. 6 .

 6 Fig. 6. Energy Value-Stream Mapping [according to 1]


Barbara Resta

Stefano Dotti

Albachiara Boffelli

Paolo Gaiardelli
email: paolo.gaiardelli@unibg.it

Environmental Management Practices for the Textile Sector

Keywords: Environmental sustainability, environmental management practices, environmental competitiveness, textile sector

Environmental sustainability is gaining more and more relevance for textile companies. However, there are often problems with application, even in the most committed companies. In this paper, an empirical typology of Italian textile firms that discern the patterns of practices used in response to environmental issues and concerns that affect such industry is proposed. The resulting typology is composed by three types: Best practice, Good practice and Bad practice. Each type is then characterised in terms of firm's characteristics and perceived environmental competitiveness benefits. The discussion of some open issues deriving from the empirical analysis precedes the final conclusion.

Introduction

Over the past decades, many companies have started to included environmental considerations into their business activities in order to decrease or eliminate the impact of these activities on the natural environment [START_REF] Bonini | Sustainability's strategic worth: McKinsey Global Survey results[END_REF]. The concept of corporate environmental management [START_REF] Greeno | Rethinking Corporate Environmental Management[END_REF] was introduced at the beginning of the '90s to help managers handle this new situation, translating the concept of environmental sustainability into a managerial tool for company managers. Although previous studies have made significant contributions to the literature on environmental issues, much still remains to be learnt about how companies include this challenge and opportunity into new strategic and operational options [START_REF] Madsen | Have Trends in Corporate Environmental Management Influenced Companies Competitiveness?[END_REF]. Moreover, most of the existing studies are too general and theoretical, and the assumption that all the business are facing a similar environmental problem is rarely appropriate [START_REF] Hubbard | Strategic Management: Thinking, Analysis and Action[END_REF]. The specific industrial context tends to shape the strategies and management sys-tems that exist at the firm-level due to its unique regulations and the influence of its stakeholders [START_REF] Chang | Industrial changes in corporate sustainability performance-An empirical overview using data envelopment analysis[END_REF]. In particular, the textile sector is one of the industries mostly affected by environmental issues and concerns: it is one of the world's largest industries, while also one of the most polluting [6]. Thus, sustainability principles, strategies and tools have then become essential for textile companies to stay competitive in the market [START_REF] Smith | Corporate Social Responsibility: Whether or How?[END_REF].

In such a context, this article aims at developing an empirical typology of the Italian textile companies by statistically identifying consistent and recurring patterns (types) of environmental management practices. The paper is organised as follows. The next section outlines the theoretical background of the study. In Section 3, the research methodology will be described by presenting the research model and the empirical study carried out in the Italian textile sector. In Section 4, the research findings are discussed and implications of the findings are presented. Finally, the last section (Section 5) closes the paper with the most relevant conclusions and future research directions.

Theoretical background

Environmental Management Practices (EMPs) refer to all the measures and activities aimed at reducing the environmental impact caused by a company's business. Despite many management practices are often lumped together as simply "environmental", it is important that practices are effectively distinguished from one another. Sroufe et al. [START_REF] Sroufe | Environmental management practices[END_REF], classified the practices on the basis of their scope, that might be operational, tactical or strategic, thus pertaining to different foci, representing different resource commitments and targeting a wide range of goals and objectives. The authors continued underlying that for a firm to be committed to environmental management, it must be aware of holistic environmental concerns, coordinating and integrating activities across operational, tactical and strategic levels. Another standpoint, relying on the resource-based view, was embraced by Lucas [START_REF] Lucas | Understanding environmental management practices: integrating views from strategic management and ecological economics[END_REF], where the EMPs were categorised along two dimensions: the different capital investment types and the stages at which they affect the production process, while Colicchia et al. [START_REF] Colicchia | Building environmental sustainability: empirical evidence from Logistics Service Providers[END_REF] distinguished between intra-organisational and inter-organisational environmental practices. The former refers to practices related to company "in-house" processes, while the latter to initiatives that imply collaboration and trust among multiple supply chain members. In general, it can be affirmed that researchers have surveyed firms' adoption of EMPs, identifying their adoption either within a specific sector, or across industries, considering specific firm size, or adopting a longitudinal perspective. EMPs have also been studied in relation to environmental and economic performance and influencing factors. However, due to the lack of an exhaustive framework for EMPs, each paper relies on a different set of practices drawn by the authors from the literature on environmental issues. To fill this gap, Resta et al. [START_REF] Resta | Practices for Environmental Sustainability in the Textile, Clothing and Leather Sectors: The Italian Case[END_REF] proposed a comprehensive classification framework for environmental sustainability practices by combining a systematic literature review with a web content analysis of ten European sustainability leaders, selected according to the Dow Jones Sustainability Europe Index. The resulting theoretical framework, containing 57 practices divided into 6 areas, represents a reference framework for EMP and is potentially applicable to every sector. In particular, it was used to survey the Italian Textile, Clothing and Leather (TCL) industry by content-analysing the corporate websites. As one of first research devoted to understanding the practices for environmental sustainability in the Italian TCL supply chain, although it is exploratory in nature, some interesting findings were hypothesised from this study. However, the direct collection of empirical data is necessary to validate the current research findings and to further describe the distribution of the environmental sustainability phenomenon in the considered population and to analyse how such phenomenon contribute to corporate competitiveness. In particular, two main research question arise: "Are there consistent and recurring patterns of environmental practices which can be viewed as an empirical typology?"; "What are the competitiveness benefits related to each type?". Therefore this study attempts to: i) discern empirically the patterns (or types) of practices used by Italian textile companies in response to environmental issues and concerns that affect such industry, ii) analyse which are the main firm characteristics (in terms of size, production segment, vertical integration, and environmental strategy) of each individuated type, and iii) identify the environmental competitiveness benefits that are related to each type.

Research Methodology

A descriptive survey research has been conducted to shed light on the above-mentioned research questions.

The conceptual model

Measures for environmental management practices were drawn from [START_REF] Resta | Practices for Environmental Sustainability in the Textile, Clothing and Leather Sectors: The Italian Case[END_REF] and were finalized during a pilot study. Several associations, both at national and European level, were also consulted. In total, 33 measures were considered, categorised into 13 categories (Product, Raw materials, Packaging, Supply chain, Transportation, Environmental Management System (EMS), Energy management, Water management, Waste management, Air emission management, Materials, Culture, Governance). For each practice, managers were asked to indicate its use (dummy variable: 0="not used"; 1="used") in the company. For each category, the intensity of EMPs was computed with an index constructed as a single scale of continual variation [0,.,1] (where 0=worst EMP profile; 1= best EMP profile), which allowed the practice aggregation process at category level. Measurement of competitiveness is complex because no commonly accepted definition of this concept exists and, consequently, it should include as many business performance dimensions as possible to provide a holistic view of environmental management's effects on firms' competitiveness [START_REF] Wagner | The effect of corporate environmental strategy choice and environmental performance on competitiveness and economic performance: an empirical study of EU manufacturing[END_REF]. Therefore, a firm's self-assessment approach based on a number of items has been employed. Environmental competitiveness self-assessment was thus measured by asking managers to select the perceived competitive benefits from a list. Then, the items were aggregated into 3 categories (Revenue growth, Cost savings and Compliance and risk), computed with an index constructed as a single scale of continual variation [0,.,1] (where 0=no environmental competitiveness; 1= high environmental competitiveness).

Data Collection and Analysis

The primary data for this study was collected through a web survey in June-July 2014. The questionnaire was administered to the total population of Italian textile companies included in the AIDA database (NACE code: 13) having an email contact publically available, totalling 1509. In total, 303 usable responses returned to the authors, corresponding to a response rate of 20%. In order to identify consistent and recurring patterns of environmental practices, agglomerative hierarchical cluster analysis was employed to group the textile companies into homogeneous categories. The software used to perform the cluster analysis statistical calculation was the IBM® SPSS® Statistics Version 20.

Results and Discussion

Cluster Analysis Results

Initially, the number of clusters had to be chosen. The hierarchical agglomerative clustering method to form groups was employed. During the course of agglomeration, squared Euclidean distance was used to calculate the distance between each pair of companies. As a result, three types (clusters) were formed. The profile of the variables for the solution with three clusters is presented in Table 1. Discriminant analysis confirmed results of the cluster analysis in verifying that all the companies were properly classified in their groups. Cluster 1. Best practice. This group represents 42 companies (14 % of the sample), and is characterised by a high receptivity to environmental issues, that are expressed in the highest level of practice implementation in all the categories but EMS. The group has the largest average turnover and the highest vertical integration: 33% of the companies covers up to 4 production segments. The cluster is characterised by the highest level of environmental strategic proactivity (2,33/3,00) and a medium level of cost savings (0,39) and competitiveness (0,30) perceived benefits. Cluster 2. Good practice. This group contains 88 firms (29% of the sample), that show a medium level of practice implementation. In average, companies included in this group have smaller dimension and a lower vertical integration compared to Group 1: 21% of the companies covers up to 3 production segments. The cluster is characterised by a high level of environmental strategic proactivity (2,23/3,00) and a medium level of cost savings (0,34) and competitiveness (0,30) perceived benefits. Cluster 3. Bad practice. This group represents 57% of the surveyed companies. These 173 firms expressed the lowest implementation of environmental management practices in all the categories. In average, companies included in this group have the lowest environmental proactivity (1,89/3,00), the smallest dimension (in terms of turnover) and the lowest vertical integration: 16% of the companies covers up to 2 production segments. The companies perceive a low level of cost savings (0,23) and competitiveness (0,22) benefits.

Environmental practice analysis and discussion

Considering the average for all the companies, practices showing the highest level of implementation are: i) waste management, in particular waste reduction (48% of the sample) and separate waste collection (89%); ii) use of process materials, in particular the use of certified materials (60%); and iii) use of raw materials, that are sustainable (64%) and certified (51%). Practices presenting the worst implementation level are: i) Culture; ii) Air emission management; and iii) Governance.

Moving from Best to Bad practice, the implementation level decreases in all the categories but EMS. This last aspect represents a warning point for companies belonging to Cluster 1: despite such firms declare to implement a high number of environmental practices in all the areas, apparently they do not have a systematic management system in place.

Overall, it can be stated that only a part of the Italian textile companies are fully concerned and committed about environmental issues and recognise the importance and necessity of incorporating environmental approaches into their management practices (Cluster 1). However, their similarities with Cluster 2 firms in terms of environmental strategic proactivity and perceived benefits poses a doubt about their leadership position: it is hard to imagine how a sustainability agenda with this many focus areas can break through and get the necessary buy-in to be successful. While there are several areas that companies need to comply with, it might be better to concentrate on a few themes and strategic priorities. To develop a clear set of priorities, it is important to start by analysing what matters most along the entire value chain, through internal analysis and consultations with stakeholders, including customers, regulators, and nongovernmental organizations. This process should enable companies to identify the sustainability issues with the greatest long-term potential and thus to create a systematic agenda.

Once the priorities are identified, the next step is to develop a fact base from which to define the practices that need to be implemented. Companies have several management tools available, such as Environmental Performance Management Systems, supported by proper Environmental Management Information Systems and controlled through flexible governance structures. All these tools find a strong basis into a pervasive culture for environmental sustainability.

Conclusion

Environmental sustainability is gaining more and more relevance for textile companies since it can positively contribute to the firm's value creation process. Several companies are starting to pave the way towards sustainability through different management systems and approaches. The objective of this study was to identify and characterise groups of Italian textile companies that are statistically similar to each other considering the environmental management practices they adopt. This was carried out using a cluster analysis. Three types were identified: Best, Good and Bad practice. Moving from Best to Bad practice, average turnover and vertical integration decrease, as well as the implementation level of environmental management practices in all the categories (but EMS). The analysis showed that, although sustainability is somewhere on the corporate agenda, there are often problems with execution, even in the most committed companies, and the necessity to focus on a limited set of strategic priorities was highlighted. Finally, some directions for future research can be pointed out to expand this work: i) include in the sample textile companies from other countries; ii) enlarge the conceptual model to social sustainability aspects; and iii) test the relationship between the implementation of environmental management practices and companies' financial results.

Table 1 .

 1 Cluster analysis of environmental practice implementation

	Cluster	1	2	3	Total
	Practices				average
	Product	0.40	0.36	0.24	0.29
	Raw materials	0.60	0.39	0.35	0.40
	Packaging	0.52	0.36	0.31	0.35
	Supply chain	0.48	0.37	0.26	0.32
	Transportation	0.50	0.44	0.30	0.37
	Environmental Management Sys-
	tem (EMS)	0.33	1.00	0.00	0.34
	Energy management	0.61	0.43	0.28	0.37
	Water management	0.71	0.29	0.15	0.27
	Waste management	0.63	0.55	0.44	0.50
	Air emission management	0.71	0.24	0.11	0.23
	Materials	0.74	0.47	0.31	0.42
	Culture	0.52	0.34	0.17	0.27
	Governance	0.33	0.23	0.04	0.14


Marise De Barros

Miranda Gomes

José Benedito Sacomano

Fabio Papalardo

Alexandre Erdmann Da Silva

Life Cycle Assessment electricity generation from landfill in São Paulo City

Keywords: Landfill, fuzzy logic, sustainability, recovers energy, renewable energy

A municipal solid waste landfills are complex systems, because your waste in a landfill body has a large heterogeneous mixture, high levels of different organic and inorganic matter. Environmental problems are results about intense urbanization, but different solutions offered for alternatives mitigating the environmental impacts. These solutions are the best practices in the recovery of such wastes when disposed of in landfills. But recent concepts in modern landfill management, in the São Paulo City, incorporate strategies in their life cycle, so since the beginning of the landfill, different techniques have been tested to stabilize the amount of methane gas emissions and energy recovery. This work finds the perspective, sustainability electricity generation, these uses of landfill gas are divided into electricity generation and direct use. The scenery, study sustainability indicators are Bandeirantes Landfill, with application of fuzzy logic to estimate production methane for energy generation.

Introduction

Recent concepts in modern landfill management, incorporate sustainability indicators in their life cycle, when the beginning of the landfill, many techniques are tested to stabilize the amount of methane gas emissions, included estimations using linear and no-linear models [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF]. Energy recovery is one of the indicators of sustainability for landfills, but these systems necessitates estimation of gas released and its energy potential, [START_REF] Kumar | Methane Production Quantification and Energy Estimation for Bangalore Municipal Solid Waste[END_REF].

Sustainability, it's a term created by the Helmholtz Institute [START_REF]Helmholtz -With Energy into the Future[END_REF], an important center of research and technology from Germany, highlights the use of energy and natural resources in an efficient, safe and sustainable way. Therefore, it defines the minimum requirements that are universally valid for the global sustainable development, unconventionally. It assigns the deficit of sustainability indicator to the forecasts of global energy shortage, to power supply or generation, to the extraction of raw materials and waste disposal without its energy recovery.

This methodological approach is based on the integrative sustainability concept developed by the Helmholtz Association. Its large idea is that the abstract notion of sustainability has to be adapted to a specific local situation, in this case, Bandeirantes Landfill, in order to make its meaning clear. Therefore, it defines the minimum requirements that are universally valid for the global sustainable development, unconventionally. It assigns the deficit of sustainability indicator to the forecasts of global energy shortage, to power supply or generation, to the extraction of raw materials and waste disposal without its energy recovery.

Landfills operating and maintenance costs are expensive for Brazilian municipalities, resolution 404 of the National Environmental Council and the law 11.107/2005, complementary to each other, assist in retrenchment strategies by the landfill sharing between municipalities in the same region [4;5]. The first one establishes a set of guidelines to obtain environmental licensing for small landfills, and the second one sets norms for the management in intermunicipal consortium [START_REF] Ministério | Agenda 21 brasileira: resultado da consulta nacional / Comissão de Políticas de Desenvolvimento Sustentável e da Agenda 21 Nacional[END_REF].

It is estimated that Brazil has 1,723 landfills, [START_REF] Ministério | Gestão do Lixo. Aterros Sanitários[END_REF]. The soil is prepared so that garbage does not affect the environment, does not cause bad odors, and does not contribute to visual pollution or to the proliferation of animals. When the waste decomposes it generates leachate: a pollutant liquid, methane gas, and other pollutants. Methane causes pollution and it is about 20 times worse for the Earth's climate than carbon dioxide emissions.

The motivation of this study reinforces that the technical parameters adopted to determine the energy potential of this type of enterprise have been developed to landfills in other countries. Therefore, design features, its operation, waste types and climatic conditions are different in the national landfills, endangering the sustainability of the landfill as an alternative energy source.

A review the life cycle Bandeirantes and parameters reference

From 2008, the Bandeirantes landfill began to operate as an independent producer and supplier of electricity. The expectation of this last phase is estimated to expire in 2030. The highest peak of sustainable production and methane generation was recorded in 2004, when it was still operating as a landfill.

Estimate the total amount of methane gas produced in landfills, variables such as time and phases of waste decomposition should be considered. Besides these influencing factors, the degradation process influences the potential to generate methane gas, which can reach about 400m3/ton of dry residue, [START_REF] Alves | Análise experimental do potencial de geração de biogás em resíduos sólidos urbanos[END_REF].

Indeed, was presented the results of a study conducted in 20 landfills in northern Germany, [START_REF] Alves | Análise experimental do potencial de geração de biogás em resíduos sólidos urbanos[END_REF]. The variations in the generation of methane depend on landfill soil compaction, on rainfall, and on the concentration of each type of material in different points. The climatic conditions of each region analyzed, as well as the operation of landfills, are also factors that influence the quality and quantity of production of methane gas. Finally, the research by this author also considered the amount of oxygen penetrating into the soil, the t soil type and its granularity and distribution of the amount of water in various parts of the landfill. Soil type and its granularity and distribution of the amount of water in various parts of the landfill.

Many procedures and methodologies evaluated two methods for the estimation landfill gas sustainability, [START_REF] Mendes | Estimate Methods of Biogas Generation in a sanitary landfill[END_REF]. One of them is called design method of IPCC [START_REF]Guidelines for National Greenhouse Gas Inventories[END_REF] and the method of first-order decay known as the equation of USEPA [START_REF]United States International Best Practices Guide for Landfill Gas energy Projects. Landfill Gas Modeling[END_REF]. The authors recommend further research on different methods, but concluded that the design method estimates lower rates of methane generation, since it takes into account the 2 Methodology

Study theoretical about Emission Factor and Collection Factor

The first equations of calculation methods for estimating methane generation did not consider the emissions, part of which migrated to the atmosphere and others were absorbed and degraded in the surface layers of the territorial plan of the landfill, among many other parameters. According to the IPCC [START_REF]Guidelines for National Greenhouse Gas Inventories[END_REF], different methods and mathematical models were used to estimate the emissions in landfills. This variability did not allow the application in regions or even in countries, due to the heterogeneity of climate, soil, rainfall, among other factors.

It was conducted in a study on the application of the mathematical model in different CDM projects in developing countries, comparing with the measured results, [START_REF] Stege | Methane Emission Reductions achieved by landfill gas projects in developing countries[END_REF]. The countries involved in the study were Brazil, China, Argentina and Chile. The author's conclusion was that the models refer to different optimal precisions of the actual measurements and cannot adequately explain the composition of the wastes and the site conditions which are different from the landfills in developed countries.

Research also emphasizes that the initial model evolved in order to improve accuracy because of the variables that affect the chemical reactions, [START_REF] Worrell | Solid Waste Engineering. 2ª Ed[END_REF]. They indicate constraints on the models such as the complexity of gas generation, depending on several variables, according to the particular conditions of each landfill, such as soil, moisture, and climate.

Thus, in order to calculate the methane generation in this study, we used the eq1 equation, as follows.

QCH4 = L0 * R * (e-kc -e-kt)

[eq1]

Where: QCH4 = Methane generated in year t (m³ / year); L0= Potential of methane generation (m³ / ton); R = Annual average of garbage input at the dump, (ton / year); K = Methane generation rate = 0.04 (half life from 4 to 2 years); c = year since the closure; t = year since the beginning of the activity (year).

It is noteworthy that, in the [eq1] equation, the variables c and t are equivalent to the variables t and y respectively presented in [eq1] equation. In [eq1], there is the representation of the sum (Σ) of all years for the decay variable. There is also a technical motivation for adopting another tool instead of the one proposed by USEPA [START_REF]United States International Best Practices Guide for Landfill Gas energy Projects. Landfill Gas Modeling[END_REF].

The first-order equation, [eq1], has the period of 1 year as time, and not the time in its lower part, for example, the production of gas in each second of time. Making projections of gas production at all time points would be limited, even if finitely. Only supercomputers could perform some processing on this level of accuracy, adding the projections of the landfill gas lifecycle of 20, 30, 40 or more years ahead.

The potential methane generation capacity, or L0, describe the total amount of methane gas potentially produced by a metric ton of waste as it decays. EPA determined that the appropriate values for L0 range from 56.6 to 198.2 m3 per metric ton or megagram (m3 /Mg) of waste, in practice. Except in dry climates where lack of moisture can limit methane generation, the value for the L0 depends almost entirely on the type of waste present in the landfill. The higher the organic content of the waste, the higher the value of L0, this is a sustainability factor. Note that the dry organic content of the waste determines the L0 value, and not the wet weight measured and recorded at landfill scale houses, as water does not generate LFG. Some tools have a refers sets L0 to a default value of 170 m3 /Mg to represent a conventional landfill.

Abrelpe [START_REF] Abrelpe | Atlas Brasileiro de emissões de GEE e Potencial Energético na Destinação de Resíduos Sólidos. Abrelpe -Associação Brasileira de Empresas de Limpeza Pública e Resíduos Especiais[END_REF] highlights the difficulty of finding the database in order to estimate accurately the values of L0 and k. It recommends the adoption of the rating factor of the waste disposal site, table [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF]. This factor is associated with L0 variable and it influences the potential of methane gas generation.

Table [1] -Emission Factor -EF

This emission factor associated with the site of residue destination interferes with the estimated portion of generation of methane gas. Landfills have factor 1 of 100%. It is estimated that these sites have adequate control regarding the handling and compaction of waste [START_REF]Sustainable Development Challenges. World Economic and Social Survey[END_REF].

The table [START_REF] Kumar | Methane Production Quantification and Energy Estimation for Bangalore Municipal Solid Waste[END_REF] presents the simulation results of the matrix that combines the emission factor and the collection factor with three types of disposal sites, according to the [eq3] equation, named for this calculation as L0'= [EF] * [CEF] .

Table [START_REF] Kumar | Methane Production Quantification and Energy Estimation for Bangalore Municipal Solid Waste[END_REF] -Simulation result for L0'(m 3 /ton)

In the simulation shown in table 2, the three categories were divided into 1 for landfill, 2 for controlling landfill and 3 to trash dump. The last one had the lowest result regarding the L0' variable. The blue column was coded for the results of 60% collection percentage and the red column to 85% performed collection.

The results emphasize that the collection factor affects the emission factor, the lower the collection factor the lower the potential for methane gas production. When the collection factor tends to increase, the potential for methane generation tends positively too. Although the collection factor is the same for landfills and controlled landfills, the numbers remained different in the two cases (EF and CEF).

Application of Fuzzy Logic Model for estimating the production of methane gas in landfill

Fuzzy logic is widely used in a machine control, for example. The term fuzzy refers to the logic involved can deal with concepts that cannot be expressed as the "true" or "false" but rather as "partially true". This paper presents fundamental ways an existing model for the numerical assessment of sustainability called sustainability assessment by fuzzy evaluation.

About the uncertainties of solid waste characteristics, as well as the complex physical, chemical, and biological processes taking place within the Bandeirantes landfill, motivated advanced modeling techniques to be applied; mathematical modeling and fuzzy logic systems [START_REF] Abdallah | Combining Fuzzy Logic and Neural Networks in Modeling Landfill Gas Production[END_REF].

3

Results and Discussion

Simulation Potential Emissions from energy recover

In this modeling of the sustainable production of electricity, the Bandeirantes landfill is named as Thermal Power Plant. The tests represent three scenarios,

In the simulation shown in chart following, the three categories were divided into 1 for landfill, 2 for controlling landfill and 3 to trash dump. The last one had the lowest result regarding the Potential of methane generation variable, fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF].

Fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF] -Simulation result for L0 (m 3 /ton) with Simulink Fuzzy

The fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF] Simulink Fuzzy was coded for the results of 60% collection percentage for trash dump and the to 85% performed collection decrease for controlling landfill. The potential of methane generation had the following results in the simulation compiled.

See fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF], the first fuzzy logic when landfill, it is not possible. The simulation of this scenario shows, in fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF], that there was an improvement in the performance of methane gas generated in all sites of waste disposal, even more at the trash dump. The simulation of this scenario shows, in fig [START_REF] Yacovitch | Mobile Laboratory Observations of Methane Emissions in the Barnett Shale Region[END_REF], that there was an improvement in the performance of methane gas generated in all sites of waste disposal, even more at the dump. The two locations of inappropriate disposal had their emissions increased. The simulation was repeated, by changing the vector order of the matrix elements. The result was exactly the same, proving that the result of the first simulation was correct, thus confirming the increase in methane generation in plants considered inadequate, but with the amount of gas production that is not used.

The performance in humid and dry climates improves gas production and affects it in semi-humid climate, according to the result of fig [START_REF] Kumar | Methane Production Quantification and Energy Estimation for Bangalore Municipal Solid Waste[END_REF]. Although it has adopted the worst values for methane production, the performance to landfill is better in the "b" case when compared with the "d" case. But case simulation "a" and "c", haven't good potential emissions.

The humid and dry climates positively affect the production of gas in the controlled landfill, staying above the result influenced by semi-humid climate in the landfill.

In 4 nd case, the results show a balanced performance. The semi-humid climate improves gas production in the landfill staying above the gas production in controlled landfill and landfill influenced by the three climates. The current Bandeirantes Thermal Power Plant was initially a trash dump, evolving to a controlled landfill and then to landfill, which was closed in 2006. This three-stage production cycle generated a volume of methane gas with potential for energy recovery.

Conclusions

They work with fuzzy logic in the future when the project goes into operation as a plant, and they do not consider the methane potential in the production cycle, discarding energy production since the establishment of the plant. In this scenario, the plant did not value 50%; this corresponds to the production of 2,356,207 MWh. It would be possible to fuel the plant and still have 2,244,175 MWh.

This simulation doesn't show that by 2030, the plant will produce 1,424,148,778 m 3 of GHG (greenhouse gas). The potential emission for recovering energy it's a good performance when increase disposal trash.

The number of controlled landfills, trash dumps and landfills that are not recovering the methane as energy and carbon credits deserves to be evaluated. Producing energy and, on the other hand, trading carbon credits on the market as a commodity of energy production can be a good investment. The issue of controlled landfills, landfills or trash dumps undergo a recent great transformation.

The fuzzy logic application in this test refines and extends tool for the numerical assessment of sustainability.

  Fig [2] -Simulation surface result for L0 (m 3 /ton) -L ( Landfill); TD (trash dump); CL (controlled landfill); PGE ( Potential gas emission)


Hamilton Boa Vista

Ytoshi Fábio

Geraldo Shibao
email: geraldo.prod@ig.com.br

Oliveira De

Lúcio T Neto

Marcelo K Costabile

Oduvaldo Shibuya

Vendrametto

Hamilton Aparecido Boa Vista

Fábio Ytoshi Shibao

Geraldo Cardoso De Oliveira Neto

Lúcio T Costabile³

Marcelo K Shibuya³

Oduvaldo Vendrametto³

{geraldo Cardoso

Oliveira Neto

Social Environmental Assessment in the Oil and Gas Industry Suppliers

Keywords: Supplier Qualification, Social and Environmental Performance, Oil and Gas 1

des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

The Brazilian equatorial margin is one of the most promising areas for exploration and production of oil and gas as part of the so-called "Golden Triangle", composed with the Gulf of Mexico, west coast of Africa and Brazilian coast. The discovery of oil deposited in the open sea (offshore), exceeds this layer of salt on the ocean floor, called "pre-salt", reaches depths of more than 7000 meters below the sea level. Moreover, it can lead Brazil to become a leading oil producer [START_REF] Anp | Brasil esta ente as mais atraentes oportunidades exploratórias do Mundo[END_REF].

The exploration and production of oil and gas in the pre-salt area is an opportunity for expansion and diversification of the Brazilian economy; therefore, in order to improve technical and productive knowledge, it is essential to develop efficient and competitive suppliers in the supply area of goods and services for this chain [START_REF] Guimarães | Política de conteúdo local na cadeia de petróleo e gás: uma visão sobre a evolução do instrumento e a percepção das empresas investidoras e produtoras de bens. Confederação Nacional da Indústria[END_REF].

The Brazilian government adopted the Law number 12.351 in December 22 nd 2010, creating the bidding system for the activities in the pre-salt area. This was the starting point for the development of local suppliers policy for the oil and gas sector in Brazil [START_REF] Brasil | Presidência da República[END_REF]. For Petrobras Oil Company, increasing local suppliers is a priority because it aims to increase its business in the long term, create a sustainable perspective, create new jobs and strengthen the national economy [START_REF]Incentivo ao Desenvolvimento[END_REF].

The literature review identified several studies about environmental qualification of suppliers studying several variables such as: green supply chain management [START_REF] Falatoonitoosi | Modeling for green supply chain evaluation[END_REF][START_REF] Pires | Gestão da cadeia de suprimentos (Supply Chain Management): conceitos, estratégias, práticas e casos[END_REF][START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF], social environmental responsibility [START_REF] Barbieri | Métodos para integrar a responsabilidade social na gestão[END_REF][START_REF] Bobsin | Gestão de segurança, meio ambiente e saúde: proposta de estrutura de sistema e metodologia de avaliação de desempenho[END_REF][START_REF] Elkington | Canibais com garfo e faca[END_REF][START_REF]Relacionamento com Investidores[END_REF], qualification of suppliers [START_REF]Incentivo ao Desenvolvimento[END_REF][START_REF]Relacionamento com Investidores[END_REF][START_REF] Rao | Do green supply chains lead to competitiveness and economic performance[END_REF][START_REF] Vanalle | Environmental requirements in the automotive supply chain-an evaluation of a first tier company in the Brazilian auto industry[END_REF], social practices [START_REF]Incentivo ao Desenvolvimento[END_REF][START_REF] Do | Cartilha A3P: Agenda ambiental na administração pública[END_REF][START_REF] Pinto | Contributions of socio-environmental certification to the sustainability of the citrus industry in Brazil[END_REF], environmental practices [START_REF] Falatoonitoosi | Modeling for green supply chain evaluation[END_REF][START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Do | Cartilha A3P: Agenda ambiental na administração pública[END_REF], social environmental investments [START_REF] Nyaga | Examining supply chain relationships: do buyer and supplier perspectives on collaborative relationships differ[END_REF][START_REF] Surroca | Corporate responsibility and financial performance: The role of intangible resources[END_REF], business performance [START_REF] Bowen | Horses for courses: Explaining the Gap Between the Theory and Practice of Green Supply[END_REF], social performance [START_REF] Neto | Gestão de responsabilidade social corporativa: o caso brasileiro[END_REF][START_REF] Do | Cartilha A3P: Agenda ambiental na administração pública[END_REF], environmental performance [START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Bowen | Horses for courses: Explaining the Gap Between the Theory and Practice of Green Supply[END_REF][START_REF] Jabbour | Are supplier selection criteria going green? Case studies of companies in Brazil[END_REF][START_REF] Kannan | Selecting green suppliers based on GSCM practices: Using fuzzy TOPSIS applied to a Brazilian electronics company[END_REF], economic performance [START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Surroca | Corporate responsibility and financial performance: The role of intangible resources[END_REF][START_REF] Porter | Toward a new conception of the environmentcompetitiveness relationship[END_REF] and environmental proactivity [START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Nyaga | Examining supply chain relationships: do buyer and supplier perspectives on collaborative relationships differ[END_REF][START_REF] Jabbour | Are supplier selection criteria going green? Case studies of companies in Brazil[END_REF][START_REF] Jabbour | Quality management, environmental management maturity, green supply chain practices and green performance of Brazilian companies with ISO 14001 certification: Direct and indirect effects[END_REF]. By analyzing the existing articles about environmental qualification of suppliers, it was found the need to study the relationship between these variables together, because some studies consider some of these variables; however, they did not find any study to present all variables simultaneously.

Thus, the aim of this paper is to verify that for the Brazilian oil and gas industry suppliers the social environmental qualification has provided a better performance for the both. The study was considered relevant because of the risk associated with the environmental impacts of exploration activities and the oil and gas production as well as the social-economic importance of the activity for the Brazilian society. Furthermore, it was considered the fact that this sector has been pioneer in the preparation of guidelines for corporate environmental management.

It has been also considered the relevance of oil activity and the social and environmental impacts of the exploration and production of offshore oil and gas fields of the "Tupi" and "Libra" that make up the Santos Basin, near the defined region for research. Therefore, it is important to the study the issues related to social and environmental performance of companies in the area of goods and services installed in the ABC Region, which is economically important for the State of São Paulo, Brazil.

In this context, this study is expected to make sure that the adoption of qualification practices established by major operators in the sector in Brazil, positively affect the social environmental performance of companies participating in or aspiring to participate in business opportunities in the oil and gas supply chain, considering the degree of risk of the activities and planned investments for the development of an oil and gas local industry, being able to meet the ongoing expansion in the sector.

Methodology

To achieve the proposed objectives, a methodological procedure conducted a descriptive research of the quantitative type, in which the objective is to evaluate the structural relationships of the proposed measurement model based on improved theoretical findings and validated by experts [START_REF] Diehl | Pesquisa em ciências sociais aplicadas: métodos e técnicas[END_REF].

The operationalization of the variables was used as the unit of analysis for companies of goods and services that provide or intend to provide for oil and gas sector in which, are interested in obtaining their qualification criteria according to Petrobras Oil Company regulations in Brazil.

Were considered as subjects of the research the directors or managers to develop activities related to procurement, engineering, environment, social responsibility, safety, logistics, human resources and other related.

For the operation of the measurement model was designed a data collection instrument, based on the theoretical foundation [START_REF] Hair | Análise Multivariada de Dados[END_REF], for the constructs: social practices, environmental practices, social environmental investments, social performance, environmental performance, economic performance and social environmental proactivity.

As a result of bibliographic research we developed a conceptual framework for the development of research, as shown in Figure 1.

1: Conceptual framework

The requirements of the market and its growing environmental expectations put pressure on suppliers to qualify for improving the performance of the contractor. Specifically, environmental practices, social practices and social environmental investment provided with products and/or services to the Brazilian oil and gas sector [START_REF] Zhu | Institutional-based antecedents and performance outcomes of internal and external green supply chain management practices[END_REF]. Based on the expected relationship between quality and environmental performance the first hypothesis arises.

H1: The qualification process for oil and gas operators positively affects the social and environmental performance of companies in the ABC region.

Proactive companies typically implement environmental practices beyond the requirements of laws and regulations, while the reactive companies only seek regulatory compliance of these requirements [START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Chandraker | Evaluation and Measurement of Performance of GSCM in Chhattisgarh Manufacturing Industries (INDIA)[END_REF].

Therefore, in the conceptual framework the environmental proactivity is a second interdependent variable that can have a significant contribution or contingent effect on the relationship of the variable independent qualification and variable dependent performance; moreover, its influence has mediating effect and its role in relation depends on the initial hypothesis. Thus, the second hypothesis is: H2: The qualification process positively affects the social and environmental proactivity of companies in the ABC region.

After, the third case emerged:

H3: The environmental proactivity positively affects the social and environmental performance of companies in the ABC Region.

In social surveys collecting data on people through observation is difficult; therefore, the researcher can use the questionnaires that have the advantage of being less expensive for its implementation, avoid biased judgments and allows respondents feel comfortable to respond due anonymity [START_REF] Silva | Métodos quantitativos na pesquisa de marketing[END_REF].

The research instrument was submitted for consideration by the respondents. Eighty questionnaires were collected; however, it was found the existence of 15 missing data; therefore, the data were considered not acceptable. Then, it was used 65 samples to treatment according to the statistical techniques using the software IBM SPSS version 22. Additionally, the test Komolgorov-Smirnov (K-S) was applied and Shapiro-Wilk to assess the normal distribution [START_REF] Conover | Rank transformations as a bridge between parametric and nonparametric statistics[END_REF].

As the result of the test showed no normal distribution, and considering that the usual statistical methods for data processing that do not have normal distribution based on multiple regression, discriminant analysis, cluster analysis, experimental analysis and cross-tabulation [START_REF] Silva | Métodos quantitativos na pesquisa de marketing[END_REF]. From this observation was carried out running tests for nonparametric data Kruskal-Wallis and the main results are presented in Table 1 [START_REF] Hair | Análise Multivariada de Dados[END_REF].

For the reliability of the data was carried out the Cronbach Alpha test, because it represents the ability to reproduce the results as needed, which showed 0,974, that is, greater than 0,05 and around 1,00 maximizing reliability and reproduction of research data [START_REF] Hair | Análise Multivariada de Dados[END_REF].

3

Results and Discussion

It was observed that the majority of respondents were in the age group from 31 to 60 years (83% of respondents) and there was greater participation of professionals aged between 31 and 40 years (33,8 % of respondents), and that most of the respondents have higher education and graduation (86,1% of respondents) which may indicate a prerequisite for the position of this person in the company.

It was noted that the vast majority of respondents within the hierarchy of the companies is situated from the range of professionals with seniority (86,2% of respondents). The corporate function in the company 38,5% of respondent exercised executive position in the company, which provides conclusion that the subject matter the board of the organizations participated of the survey.

In addition, most respondents worked in the company three years or more (87,7% of respondents). The largest shares were professional with over 10 years in the company (35,5% of respondents). The company time leads us to infer that respondents have sufficient knowledge of the company's management processes.

It was subsequently performed testing normality K-S and Shapiro-Wilk, in both tests all had lower values assertions 0,001 indicating non-adherence normal curve [START_REF] Hair | Análise Multivariada de Dados[END_REF] and Cronbach Alpha test to verify the reliability of data [START_REF] Hair | Análise Multivariada de Dados[END_REF] that presented 0,974.

Then the test was performed for non-parametric data [START_REF] Hair | Análise Multivariada de Dados[END_REF]. The main results are summarized in Table 1. Regarding H1, respondents showed strong agreement in relation to meeting social and environmental requirements for oil and gas operators. Noted that the greatest degree of agreement occurred in respondents that work time above 10 years in the company. The treatment to social and environmental requirements of the operators is directly related to the qualification construct [START_REF] Rao | Do green supply chains lead to competitiveness and economic performance[END_REF][START_REF] Vanalle | Environmental requirements in the automotive supply chain-an evaluation of a first tier company in the Brazilian auto industry[END_REF].

It is emphasized that the age group 31-50 years old had the highest degree of agreement in relation to financial resources as important for the environmental performance of companies [START_REF] Nyaga | Examining supply chain relationships: do buyer and supplier perspectives on collaborative relationships differ[END_REF][START_REF] Surroca | Corporate responsibility and financial performance: The role of intangible resources[END_REF]. Regarding the initiative to provide safety information of products and/or services to your customers can be considered an environmental proactive measure contributing positively to the businesses performance, supporting the findings of [START_REF] Nyaga | Examining supply chain relationships: do buyer and supplier perspectives on collaborative relationships differ[END_REF][START_REF] Jabbour | Quality management, environmental management maturity, green supply chain practices and green performance of Brazilian companies with ISO 14001 certification: Direct and indirect effects[END_REF].

On the other hand, there was a discordance of the respondents regarding the practice of environmental audits of suppliers regarding time spent in the company. Despite the practice of holding environmental audits of suppliers was positive for environmental performance [START_REF] Bowen | Horses for courses: Explaining the Gap Between the Theory and Practice of Green Supply[END_REF][START_REF] Jabbour | Are supplier selection criteria going green? Case studies of companies in Brazil[END_REF][START_REF] Kannan | Selecting green suppliers based on GSCM practices: Using fuzzy TOPSIS applied to a Brazilian electronics company[END_REF], the data were inconclusive.

Referring H2, it was observed that the Mann-Whitney test made the crosstabulation of the responses to the variable "Your company already provides for the oil and gas sector", the results as the existence of the commitment to the fundamental rights worker safety by the company you work, promote respect for the fundamental rights of its employees and meet all the social and environmental requirements for oil and gas operators, the most respondents agreed (36 respondents), even those who work in companies that do not provide for the oil and gas sector (23 respondents), denoting that the sample respondents agree that for the environmental qualification is important the Social and Environmental Practices [START_REF] Do | Cartilha A3P: Agenda ambiental na administração pública[END_REF][START_REF] Pinto | Contributions of socio-environmental certification to the sustainability of the citrus industry in Brazil[END_REF]. Thus, the process for social environmental qualification of suppliers encourages the adoption of the practices for this purpose [START_REF] Pinto | Contributions of socio-environmental certification to the sustainability of the citrus industry in Brazil[END_REF].

The cross-tabulation of the variable certifications in relation to the other assertions made possible show a high degree of agreement of respondents, and not related to the fact of the companies they own certification. Therefore, the variables related to social environmental practices and performance were confirmed positive [START_REF] Srivastava | Green supply-chain management: a state-of-the-art literature review[END_REF][START_REF] Do | Cartilha A3P: Agenda ambiental na administração pública[END_REF][START_REF] Surroca | Corporate responsibility and financial performance: The role of intangible resources[END_REF][START_REF] Bowen | Horses for courses: Explaining the Gap Between the Theory and Practice of Green Supply[END_REF][START_REF] Neto | Gestão de responsabilidade social corporativa: o caso brasileiro[END_REF][START_REF] Jabbour | Are supplier selection criteria going green? Case studies of companies in Brazil[END_REF][START_REF] Kannan | Selecting green suppliers based on GSCM practices: Using fuzzy TOPSIS applied to a Brazilian electronics company[END_REF][START_REF] Porter | Toward a new conception of the environmentcompetitiveness relationship[END_REF].

Regarding H3, it was identified about ISO 14001 certification, it was found disagreement regarding environmental performance audits of suppliers. It should be noted that most of the responding companies were not certified and certified companies have strong agreement. Showing that environmental certification influenced the degree of agreement of the sample. Therefore, the environmental certification should be encouraged to improve the environmental performance of companies located in the ABC region. The suggestion is that a more detailed research would be better in the future.

The certification for the finding affects the environmental proactivity of enterprises, confirms the assumption [START_REF] Porter | Toward a new conception of the environmentcompetitiveness relationship[END_REF], as a "win-win" situation, in which, both the environmental and the organizational performances of companies would be favored with effective environmental management.

Conclusions

The process of qualification of operators does not affect the environmental performance of companies according to the sampling plan of the survey, that is, the central hypothesis was not confirmed (H1), because the respondent companies consider that the qualification is associated only to the process of highlighting the safety information of the products and/or service and not the need to be certified. Thus, these companies do not achieve control practices through audits, due to the low quantity of certified companies, showing a weakness in relation to performance.

In relation to (H2), it was found that companies understand that the use of social and environmental qualification process for suppliers drives the adoption of practices for this purpose. However, they do not consider that the most important is the fact they have certification, but if the supplier has environmental practices in routine work. Therefore, the certification has not been confirmed as proactive for environmental qualification of suppliers. However, it was observed effect of the environmental proactivity of business (H3), trusting that the environmental certification should be encouraged as a practice and not as necessary documentation. The most important is to verify that suppliers have environmental practices adopted proactively, improving performance.

An important aspect of this analysis is the lack of control through social environmental audits on suppliers. Due to this finding, suppliers located in the ABC region should consider the implementation of the practice of holding social environmental performance audits of its suppliers, because the literature review indicated positive results regarding the improvement of environmental performance and necessary for the insertion of the company in Green Supply Chain.

The conceptual framework that was tested can be used to provide managers and researchers with constructive support to managerial decision-making and for future academic research. A limitation of this study was unable to generalize the results by sample, which happened only with suppliers located in the ABC region.

Table 1 -Summary Cross-tabulation

 1

		Assertive	n 1	A 2	N 3	D 4	Chi-Sq 5	Df 6	Sig 7
	Age group (31-40 years)	Provides its customers with information on product safety	22	19	1	2	10,719	4	0,30
	Worked in company (10 years more)	Performs audit environmental performance of suppliers	23	4	5	14	9,404	3	0,24
	Worked in company (10 years more)	Meets social and environmental operators requirements of oil and gas	21	17	4	0	8,126	3	0,43
	1 Number of events (n)

2

Number of respondents who agree with the assertive (Agree)

3

Number of respondents who do not agree nor disagree with the assertive (Agree nor Disagree)

4

Number of respondents who disagree with the assertive (Disagree)

5

Chi-square

6

Degree of freedom 7 Significance (p)

Moreover, it is suggested to further studies in order to obtain a larger sample, another point is to verify that the practice of social environmental audit in suppliers can improve social environmental performance.


Marcelo Kenji Shibuya
email: marcelo.shibuya@gmail.com

Irenilza De
email: irenilza@gmail.com

Alencar Näas

Mario Mollo Neto
email: mariomollo@gmail.com

Irenilza De A Näas

Flexible Ethanol Production: Energy from Sugarcane Bagasse Might Help the Sustainability of Biofuels

Keywords: Biofuel, Ethanol, Energy Efficiency

ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Introduction

Anhydrous ethanol is the most important additive mixed with gasoline and hydrated ethanol can be used as an alternative fuel for flex-fuel vehicles that may either pure gasoline, hydrated ethanol or a mixture of both in any proportion [START_REF] Coelho | Brazilian Sugarcane Ethanol: Lessons Learned[END_REF][START_REF] Freitas | Ethanol Demand under the Flex Fuel Technology Regime in Brazil[END_REF]. Since 2009, a reduction of hydrous ethanol demand in Brazil began, which rose from 16,471 million cubic meters in this year to the volume of 9,793 million cubic meters in 2013 [START_REF]Gás Natural e Biocombustiveis[END_REF]. Gasoline, on the other hand, was used in the volume of 25,409 million cubic meters in 2009, and trespassing the 39,678 million cubic meters in 2013.

The increase in fossil fuel consumption and the reduction of the biofuel demand is shown by [START_REF] Nogueira | Biofuels in Brazil: Evolution, Achievements and Perspectives on Food Security[END_REF] as a period of stagnation and expansion interruption about the sugarcane industry in Brazil. The same authors add that what contributed to this phase of stagnation was the government intervention in gasoline prices, which occurred from 2008 to 2012 to fight inflation rate. This interference has caused the price of commercial gasoline to fall to a price lower than the international oil barrel price, affecting the relative price of ethanol and the fossil fuel. Also, there was a decline in productivity in the sugar cane plantation, helping to intensify the crisis in the sector. Still, according to the authors, the reduction ethanol plants expansion and shifting of the biofuel supply, determined the increase in their prices to consumers and thus reduced their consumption.

Brazilian plants of ethanol production are self-sufficient in energy [START_REF] Dantas | Energy from Sugarcane Bagasse in Brazil: An Assessment of the Productivity and Cost of Different Technological Routes[END_REF], which is one of the competitive advantages of the ethanol produced in the country. Under this approach, the combination of the availability of ethanol plants and surplus energy obtained from sugarcane bagasse and corn production in the same geographic region, corn ethanol would have conditions to be produced. Therefore, as defined by [START_REF] Aprosoja | I Forum Brasileiro de Etanol de Milho e Sorgo[END_REF], there is a need to adapt these plants to operate with both raw materials. The author indicates that when the industrial plant originally built for processing sugar, starts to process corn it requires an investment of near US$ 8,5 million.

This article aims to analyze the additional ethanol that could be produced using corn as raw material, and the excess energy obtained from sugarcane bagasse in the plants located in the Midwest of Brazil. In this way, the additional ethanol produced from corn help make the Brazilian ethanol production sustainable. The present study was conducted in this geographic region because it has ethanol production from sugarcane and corn as raw material.

2

Literature Review

Sugarcane ethanol and corn ethanol production in the Midwest of Brazil.

According to [START_REF] Hofsetz | Brazilian Sugarcane Bagasse: Energy and Non-energy consumption[END_REF], the production of ethanol from sugarcane occurs simultaneously with the sugarcane harvest, that is, from March to December of each year. The author [START_REF]Gás Natural e Biocombustiveis[END_REF] define that the higher volumes of biofuels are produced in the intermediate harvest months, from July to September. This feature of production makes ethanol prices higher to consumers, in the offseason of sugarcane and start the production cycle, when the biofuel stocks tend to be at lower levels [START_REF]Gás Natural e Biocombustiveis[END_REF].

Brazilian production of ethanol from the sugarcane and the use of flex-fuel vehicles are world references in renewable energy [START_REF]Gás Natural e Biocombustiveis[END_REF]. The same author adds that ethanol production has promoted the rural development, diversification of energy sources, reduction of dependence on imported oil, and especially the reduction of air pollution and greenhouse gasses. The regional production of ethanol from sugarcane for the year 2013 is presented in Table 1.

Brazil is a pioneer in the production of sugarcane ethanol, has been successful in overcoming the initial challenges for developing this fuel, making efficient use of agricultural production technologies, modern management practices of crop, and the use of bagasse after grinding to generate heat and electricity for the production of ethanol [START_REF] Du | Flex Fuel Vehicle Adoption and Dynamics of Ethanol Prices: Lessons from Brazil[END_REF]. Two crops of corn are harvested in Brazil per year [START_REF] Conab | Acompanhamento da Safra Brasileira -Grãos; V1 -Safra[END_REF]. The first crop has a cycle from October of one year to April of the following year; and the second crop (also known as a winter crop), occurs from January to July of the same year. The second crop of corn alternates the soil with soybeans. The potential of increasing production of corn to 72.239 million tons, in case of using all soybean planting area, [START_REF] Bndes | A Produção do Etanol pela Integração do Milho-Safrinha às Usinas de Cana de Açúcar: Avaliação Ambiental[END_REF]. The same author adds that due to high costs of transporting the surplus production from the Midwest, the production of second maize crop of this region is economically attractive only in the periods of high international prices. These factors make the second maize is a viable alternative as raw material for ethanol production in this region. Table 2 shows the production details in the Midwest region of Brazil. The states of Mato Grosso (MT), Mato Grosso do Sul (MS), and Goiás (GO) composes the region. Table 2 also indicates the respective amounts of ethanol plants installed, the average days of operation of the plants, and the quantities harvested in the second corn crop in 2013.

2.2

Corn Ethanol: the American experience and perspectives for production in Brazil.

In the United States, the ethanol produced from corn is currently the dominant biofuel, using 30% of the total corn production in the country. According to [START_REF] Hettinga | Undestanding the Reduction in US Corn Ethanol Production Costs: An Experience Curve Approach[END_REF], two processes are used to produce ethanol from corn: dry or wet milling. Milling ethanol by the wet method provides a greater amount of by-products such as corn oil, carbon dioxide gas, starch, and approximately 440 liters of anhydrous ethanol per ton of corn. Furthermore, ethanol production by the dry process has attracted major interest by producers, for providing a higher amount of biofuel production (460 L of anhydrous ethanol plus 380 kg DDGS-Distillers Dried Grains with Solubles) per ton of processed corn.

One of the disadvantages of the production of ethanol from corn from corn is the impossibility of total utilization of biomass corn as a source of power generation, as occurs with the bagasse from sugarcane. According to [START_REF] Hofsetz | Brazilian Sugarcane Bagasse: Energy and Non-energy consumption[END_REF][START_REF] Crago | Competitiveness of Brazilian Sugarcane Ethanol Compared to US Corn Ethanol[END_REF], the corn harvest generates straw, stem, leaves and cobs left n the field to preserve fertility and soil moisture. Thus, in the US, other energy sources are used, such as natural gas or shale gas. Regarding the characteristics of the raw materials used for ethanol production, sugarcane should be ground and processed within hours of harvest otherwise there is the loss of sucrose and, therefore, the reduction of the ethanol or sugar production [START_REF] Bndes | A Produção do Etanol pela Integração do Milho-Safrinha às Usinas de Cana de Açúcar: Avaliação Ambiental[END_REF]. On the other hand, corn does not undergo this problem and may be stored for long periods.

Data from December 2013 to April 2014 [START_REF]UNICA -União da Indústria da Cana de Açúcar; Relatório Final da Safra 2013-2014[END_REF] from two plants in the state of Mato Grosso (MT) converted to operate simultaneously with sugarcane and corn, showed a production of 0.37 million cubic meters of ethanol from corn. The product used was the leftover of the winter crop in that state. It should be noted that the use of grain for ethanol production occurred precisely in the off-season of sugarcane, which occurs from December to April when the plants are interrupted for lack of sugarcane.

It was recently reported [START_REF]UNICA -União da Indústria da Cana de Açúcar; Relatório Final da Safra 2013-2014[END_REF] the income earned by the plants installed in the state of Mato Grosso, with 0.352 m 3 of ethanol per ton of corn and 169.5 kg of DDGS per ton of corn. An important point to note, especially when analyzing the sustainability and competitiveness of ethanol production, is the consumption and how to obtain the energy used in industrial steps. In a published study [START_REF] Salla | Análise Energética na Produção de Etanol de Mandioca, Cana de Açúcar e Milho[END_REF] the authors state that the industrial processing of a ton of sugarcane, to obtain 85 L of ethanol consumes 1641.56 MJ, while processing a ton of corn produces 352 L of ethanol and consumes 3882.39 MJ of energy. These data become important when placed in the analysis of sugarcane bagasse that is the main source of supply of thermal and electric energy for ethanol production in the plants. According to [START_REF] Lamonica | Produção de Vapor e Eletricidade -A Evolução do Setor Sucroalcooleiro[END_REF], processing a ton of sugarcane generates 276kg of bagasse with potential energy of 2503.71 MJ, and when the harvest is mechanized, it can obtain the amount of 165 kg per ton of cane straw harvested, which has the potential energy of 2143.64 MJ.

Considering the losses of 21% in the conversion of the burning of sugarcane bagasse or straw, to obtain steam in the sugarcane plants [START_REF] Lamonica | Produção de Vapor e Eletricidade -A Evolução do Setor Sucroalcooleiro[END_REF], one can estimate that, to process a ton of sugarcane there is a brute availability of 2503.71 MJ of energy through bagasse, and consume of 525.78 MJ in the process of obtaining ethanol, with an extra amount of 336.37 MJ, which could be used to process corn for the production of ethanol.

Methodology

In this article, ethanol production potential in the Midwest region of Brazil was estimated through simulation, taking into account the use of sugarcane during their respective harvest and corn during the off season from sugarcane. The data used in the study was obtained from [START_REF]Gás Natural e Biocombustiveis[END_REF][START_REF] Conab | Acompanhamento da Safra Brasileira -Grãos; V1 -Safra[END_REF][START_REF] Conab | Perfil do Setor do Açúcar e do Álcool no Brasil[END_REF]. From these data, we estimated the potential contribution that corn ethanol could bring to the biofuel supply in the Midwest of Brazil. Calculations were performed in two different scenarios. In the first, the production of sugarcane ethanol was considered, in volumes achieved in 2013, and the excess energy from sugarcane bagasse being used for the production of corn ethanol. In this case, the limit of corn ethanol production could come from energy availability or availability of cereal in each analyzed state. The determinist simulation was adopted, and the production process variability was not considered (such as raw material quality).

In the second scenario use of energy from sugarcane bagasse and straw as energy source for obtaining the volume of ethanol was considered. In relation to the volume of corn used for ethanol production, it was necessary to consider between 1) the amount of corn processable due to the availability of energy; 2) the amount of grain from the harvest of the second crop; and 3) the amount of corn required for the production of 120 days of ethanol, having as a basis, the average volume obtained from the sugarcane.

The simulation of scenarios 1 and 2 are described by equations 1, 2, 3 and 4.

(

) 1
Where: D Ec = energy available from the sugarcane bagasse (in MJ), V e = volume of produced ethanol (m 3 ), 0,085 = volume of ethanol (m 3 ) produced per ton of sugarcane, 2.503 = Amount of energy obtained from the bagasse of 1 ton of sugarcane in MJ.

(

Where: D Ep = energy available from the sugarcane bagasse (in MJ), V e = volume of produced ethanol (m 3 ), 0.085 = volume of ethanol (m 3 ) produced per ton of sugarcane, 2,503 = Amount of energy obtained from straw per ton of sugarcane in MJ.

(3)

Where: E ex = Excess energy available to the industrial processing of corn (in MJ), D e = Availability of energy from sugarcane bagasse (in MJ), E c = energy used for the processing of sugarcane ethanol production (in MJ). [START_REF] Nogueira | Biofuels in Brazil: Evolution, Achievements and Perspectives on Food Security[END_REF] Where: E M = Volume of ethanol obtained from corn (in m 3 ), E ex = Excess energy Available for the processing of corn ethanol (in MJ), E pm = Energy necessary for the processing of 1 ton of corn (in MJ), 0,350 = Volume of ethanol obtained (in m 3 ) in the processing of 1 ton of corn.

Results and Discussion

Tables 3 and4 show the results obtained from the simulations performed. On the first scenario, it was possible to estimate 2,537.9 cubic meters of ethanol from corn, an additional 35.21% of the production of sugarcane ethanol. Note that in bold are the values of corn considered in the processing of ethanol. In scenario 2, the use of available energy (from the former originator of sugarcane bagasse and straw), the volume of processable corn with the available energy, the daily amount of processable corn, and the corn harvested in 2013 crop were considered. In Table 2, in bold, there are defined the amount of corn that were considered for the production of ethanol, according to the conditions stated in methodology. Note that in this scenario, it was possible to obtain an additional 66.08% compared to ethanol obtained from sugarcane.

The results of the study showed that ethanol produced from the cereal can give a large share of contribution to the increase of biofuel supply in Brazil. Thus, the deficit of biofuel announced by [START_REF] Nogueira | Biofuels in Brazil: Evolution, Achievements and Perspectives on Food Security[END_REF] would be minimized, giving conditions for the sector to re-grow with increasing demand for biofuel As defined by [START_REF] Aprosoja | I Forum Brasileiro de Etanol de Milho e Sorgo[END_REF][START_REF] Bndes | A Produção do Etanol pela Integração do Milho-Safrinha às Usinas de Cana de Açúcar: Avaliação Ambiental[END_REF], the present study considered the corn processed in off-season periods of sugarcane, that is, from January to April, when the ethanol processing plants are interrupted for lack of cane sugar. Thus, there is less inactivity in power plants, considering that the yield of sugarcane ethanol is produced from this raw material and other periods can use as a cereal raw material. Another observation to be added is related to the sale price of corn ethanol by producing plants. As the production of corn ethanol is practiced in the offseason of sugarcane, as cited by [START_REF]Gás Natural e Biocombustiveis[END_REF], producers can benefit from it, and have more attractive prices in marketing their products.

Concerning the energy needed for producing ethanol from corn, the current study showed that the use of the excess sugarcane bagasse is possible to increase in 35.21% the ethanol production; and the use of excess sugarcane bagasse and straw, can increase 66.08%. Both studies considered the regional cereal availability, availability of energy and the maximum production by the State plants. These results show that the conversion of energy plants to operate with corn can help the energy efficiency of production facilities to increase production of biofuels with greater use of excess biomass. This energy efficiency is a competitive advantage of the plants prepared to operate with the two raw materials in relation to the typical American plants, as defined by [START_REF] Hofsetz | Brazilian Sugarcane Bagasse: Energy and Non-energy consumption[END_REF][START_REF] Crago | Competitiveness of Brazilian Sugarcane Ethanol Compared to US Corn Ethanol[END_REF] which require external energy for processing corn.

Finally, we must add a note about the storage aspects of the two raw materials. As defined by [START_REF] Bndes | A Produção do Etanol pela Integração do Milho-Safrinha às Usinas de Cana de Açúcar: Avaliação Ambiental[END_REF], sugarcane must be processed hours after harvest, and corn can be stored for a longer period. The plants adapted to operate with both raw materials can benefit from this feature, because could be used to meet the agricultural productivity fluctuations of sugarcane, as reported by [START_REF] Nogueira | Biofuels in Brazil: Evolution, Achievements and Perspectives on Food Security[END_REF].

Conclusion

The study showed, for the Midwest region of Brazil, the additional volumes of ethanol that can be produced with the use of corn-producing plants previously adapted from only processing sugarcane ethanol. These results were obtained by simulation, considering the use of biomass from sugarcane. From the results obtained, it was possible to prove the energetic feasibility that the plants have to adapt to the operation with corn as raw material. Also to increasing the production, it is concluded in the present study that the use of corn can reduce inactivity of the ethanol plants in the off periods of sugarcane, using corn as raw material. Another benefit of the use of corn would be its use to minimize the effects of fluctuations in the production of sugarcane due to climatic factors. The results of the current study could be useful for both producers and policy makers. For producers, the study may predict the amount of ethanol that might be increased due to the addition of corn in the process. For policy makers, the study may subsidize information for the political decision-making process in biofuels in the country.

In future research, detailed studies could be carried out considering the monthly variation in the supply of sugarcane and the use of corn as an instrument to maintain the production in volumes of ethanol.

Table 1 .

 1 Brazilian regional production of ethanol (source:[START_REF]Gás Natural e Biocombustiveis[END_REF])

	Region	Production 2013	Production Percentage
	North	253.61	0.91%
	Northeast	1,703.67	6.13%
	Southeast	17,167.74	61.74%
	South	1,475.83	5.31%
	Midwest	7,207.75	25.92%
	Brazil in Total	27,808.59	100%

Table 2 .

 2 Number of plants, average days of operation and the second corn crop (source:[START_REF]Gás Natural e Biocombustiveis[END_REF][START_REF] Conab | Acompanhamento da Safra Brasileira -Grãos; V1 -Safra[END_REF][START_REF] Conab | Perfil do Setor do Açúcar e do Álcool no Brasil[END_REF])

	State	Quant.	Average days
		Plants	of	operation
			per year

Sugarcane ethanol pro- duced in the crop of 2014 (10 6 m 3 )

					Second corn crop
					in 2012
					(10 6 ton)
	MS	23	222	2248.37	7,451.1
	GO	36	183	3871.93	4,816.9
	MT	9	173	1087.46	19,357.8

Table 3 .

 3 Results of the simulation for scenario 1

	State	Second	Processable corn due	Excess	Sugarcane	Corn etha-
		corn crop -	to excessive energy	Energy	ethanol	nol (m 3 )
		ref. 2013	available (ton)	(10^6	(m 3 )
		(ton)		MJ)
	MS	7,451,100	2,291,755	8,897	2,248,370	802,114
	GO	4,816,900	3,946,643	15,322	3,871,930	1,355,176
	MT	19,357,800	1,108,444	4,303	1,087,460	380,611
			Total		7,207,760	2,537,901

Table 4 .

 4 Results of the simulation for scenario 2.

	State	Second	Processable	Processable	Excess	Sugar-	Corn
		corn crop	corn due to	corn in 120	Energy	cane eth-	ethanol
		-ref. 2013	excessive	days of	(10^6	anol (m 3 )	(m 3 )
		(ton)	energy	production.	MJ)
			available	(ton)
			(ton)
	MS	7,451,100	13,829,704	6,252,671	53,692	2,248,370	2,188,435
	GO	4,816,900	23,816,208	3,175,978	92,464	3,871,930	1,111,592
	MT	19,357,80	6,688,957	4,180,598	25,969	1,087,460	1,463,209
		0
			Total			7,207,760	4,763,237