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Countries around the world are devising and implementing bioeconomy strategies to initiate transformation towards sustainable futures. Modern concepts of bioeconomy extend beyond bio-based energy provision and include: (1) the substitution of fossil resource-based inputs to various productive sectors, such as the chemical industry and the construction sector, (2) more efficient, including new and cascading uses of biomass, and (3) a low bulk, but high-value biologisation of processes in agro-food, pharmaceutical, and recycling industries. Outcomes of past attempts at engineering transformation, however, proved to be context-dependent and contingent on appropriate governance measures. In this paper we theoretically motivate and apply a system-level theory of change framework that identifies central mechanisms and four distinct pathways, through which bio-based transformation can generate positive or negative outcomes in multiple domains of the Sustainable Development Goals. Based on emblematic examples from three bio-based sectors, we apply the framework illustrating how case-specific mixes of transformation pathways emerge and translate into outcomes. We find that the observed mixes of transformation pathways evoke distinct mechanisms that link bioeconomic change to sustainability gains and losses. Based on this insight we derive four key lessons that can help to inform the design of strategies to enable and regulate sustainable bioeconomies., This work was supported by the German Federal Ministry of Education and Research [grant number 031B0019]; and the Ministry of Culture and Science of North Rhine-Westphalia within the framework of the NRW Strategieprojekt BioSC [grant number 313/323-400-00213]; and the German Research Foundation under Germany´s Excellence Strategy [EXC-2070-390732324-PhenoRob].

Western diets are associated with multiple environmental impacts and risks to human health. European countries are gradually taking action towards the Farm to Fork Strategy, embracing a Life Cycle Assessment (LCA) perspective to promote the sustainability of food production and consumption. Although LCA enables the comprehensive assessment of environmental impacts, diet-related human health and animal welfare impacts are often underrepresented. This study proposes integrating additional indicators into LCA to evaluate the sustainability of diets under the One Health (OH) approach, which holistically considers interlinked complex health issues between humans, animals and the environment. Human health loss is estimated according to risk factors for non-communicable diseases; while animal welfare is measured as animal life years suffered, loss of animal lives and loss of morally-adjusted animal lives. The extended LCA framework is applied to men and women's reference diets in the German federal state of North Rhine-Westphalia (NRW); compared to three optimized dietary scenarios under nutritional constraints: 1) the national dietary guidelines, 2) a vegan diet (VD) and 3) a Mediterranean diet (MD). Men's reference diet causes greater impacts than women's across OH dimensions due to the higher food consumption, especially of ready-to-eat meals, sausages, meat, and sweetened and alcoholic beverages. Both reference diets are associated with risk factors for cardiovascular diseases, diabetes, stroke and neoplasms. Besides meat, consumption of honey, fish and seafood has the greatest impact on animal welfare, because of the high number of individuals involved. Alternative diets improve the sustainability of food consumption in NRW, although trade-offs arise: MD worsens animal suffering due to the higher fish intake; water use increases in both VD and MD due the higher intake of nuts and vegetables. Results highlight the importance of including animal welfare and human health indicators in LCA to better elucidate the potential impacts of diets characterized by the high intake of animal products, from a OH perspective.

Expanding the production of fuels and fibres based on traditional food crops can put additional pressures on ecosystems and natural resources, with potential spillover effects through induced land use change (iLUC). Computable General Equilibrium (CGE) modelling provides a systematic framework for ex-ante sustainability analysis, capturing the complex interactions between land uses, agri-food markets, and international trade. This study applies an integrated CGE framework that considers loss of natural vegetation to derive quantitative indicators on the sustainability of manufacturing bioplastics from arable crops in five major producing regions (Brazil, China, the European Union, United States and Thailand). The approach consists of increasing bioplastics production at the cost of conventional plastics in each of these regions separately by means of a production subsidy, simulating bioplastic production targets. In order to assess the uncertainty in sustainability metrics, different levels of market penetration are considered, as well as variability in key model parameters. Increasing bioplastics production in Thailand is in general associated with more favourable metrics, although this is related to the relatively small size of the sector, which triggers minor market-mediated effects. When iLUC is included, increased bioplastics production in China is, on average, associated with the largest land footprint (16.93 ha t–1); whereas the highest CO2 emission intensity is estimated for bioplastics produced in the European Union (10.41 t CO2-eq. t–1). Emissions from iLUC outweigh potential greenhouse gas (GHG) savings from fossil fuel substitution, except for Thailand, where increasing bioplastics production from sugarcane and cassava saves on average 2.0 kg CO2-eq. t–1. This translates into decades of carbon payback time and high abatement costs even for Thailand, while trade-offs arise among the metrics proposed. Other impacts besides deforestation and GHG emissions should ideally be considered to examine further interactions within the Water-Food-Energy nexus, though this may require combining global with regionalized approaches, with the associated challenges.

Industries across the world are making a transition from fossil resources to renewable biological feedstock for the production of chemicals, fuels, and materials, as a strategy to promote sustainable development and economic growth. However, limited biomass availability can halt the expansion of bio-based sectors, unless alternative raw materials are employed and cascading uses are implemented on a large scale. Key Enabling Technologies (KETs) can contribute to feedstock diversification and improved biomass conversion efficiencies along supply chains, although concerns arise about their actual viability and competitiveness. A systematic review of Life Cycle Assessments (LCAs) and related process-based approaches is carried out to evaluate the sustainability of advanced bio-based technologies, defined as those that use either non-food feedstock or circularity principles –or both– for delivering diverse products. A classification scheme is proposed to categorise KETs based on the feedstock employed (plant residues and perennials, designer crops, algae, or biological waste) or the underlying technological configuration (enzyme/microbial assisted processing or biorefineries). Results show that producing biofuels and biochemicals from perennial plants, lignocellulosic residues and algae has advantages in terms of greenhouse gas emissions relative to their fossil counterparts, while trade-offs occur with other environmental impacts and sustainability dimensions. Cradle-to-cradle systems can deliver additional sustainability gains, but their implementation poses technical and socio-political challenges. Further harmonisation of LCA methodologies is desirable to compare KETs in different sectoral, geographical and policy contexts. In spite of the diversity of outcomes and approaches, this review provides an overview of advanced bio-based technologies, while shedding light on the often overestimated sustainability benefits of the bioeconomy.

Biochemicals constitute a key sector in the bioeconomy, but their future expansion depends on biomass availability. This study employs an integrated global Computable General Equilibrium (CGE) modeling approach to quantify the impacts on land-use change, greenhouse gas (GHG) emissions and socioeconomic indicators, when reducing biomass conversion costs for global biochemical production by 1.5% annually until 2050. Global demand for crop- and forest-based feedstock by the chemical industry increases sharply in 2050, e.g. by 327% for wheat; driving up agro-food prices, e.g. by 3.5% for oilseeds and 3.9% for sugarcane in Brazil. Chemical output decreases in countries that rely on imported biomass for biochemical production, such as Germany, France or the United States; while it increases, for instance, in Brazil and Australia, which draw mainly on domestic feedstock. Increased biomass demand entails significant natural forest cover loss across South America and Asia, and, to a lesser extent, in North America. Associated GHG from global carbon stock losses outweigh those from fossil fuel savings, increasing GHG emissions globally by 107 Mt in 2050, relative to the baseline. Results suggest that R&D investments in bio-based sectors should be complemented with coherent policies to prevent deforestation and negative impacts on the Sustainable Development Goals.

Power-to-Fuel (PtF) systems use carbon dioxide and hydrogen as feedstock together for renewable fuel production and can hence contribute to climate change mitigation. This study assesses the environmental performance, from cradle to gate, of an innovative PtF system for synthetic methanol production, which integrates a biogas plant based on manure and straw residues as well as a combined heat and power unit. Under this concept, the residual carbon dioxide from biogas production is used for the synthesis of methanol, whereas hydrogen is obtained via wind-based electrolysis. A life cycle assessment (LCA) is carried out here for 1 kg of methanol produced with the integrated system proposed, operated on a small scale. In view of the multi-functionality of the process, the uncertainty in LCA outcomes is assessed by considering different assumptions on co-product credits for both the electricity from cogeneration and the digestate from the anaerobic digestion of organic raw materials. Additionally, a sensitivity analysis is performed to examine the influence of variability in life cycle inventory data on the results. All the analysed scenarios show significant improvements compared with conventional methanol production from fossil resources (with only a few exceptions for acidification and eutrophication). The sensitivity analysis shows that parameters determining the overall energy requirements as well as methane losses from anaerobic digestion in the PtF system greatly influence its environmental performance, and should be carefully considered in process design and upscaling. In spite of the uncertainty inherent in LCA, the system is presented as an interesting option to produce renewable methanol while contributing towards a circular economy, provided that the economic performance is also beneficial relative to the fossil alternative.

Reliable estimates of carbon and other environmental footprints of agricultural commodities require capturing a large diversity of conditions along global supply chains. Life Cycle Assessment (LCA) faces limitations when it comes to addressing spatial and temporal variability in production, transportation and manufacturing systems. We present a bottom-up approach for quantifying the greenhouse gas (GHG) emissions embedded in the production and trade of agricultural products with a high spatial resolution, by means of the integration of LCA principles with enhanced physical trade flow analysis. Our approach estimates the carbon footprint (as tonnes of carbon dioxide equivalents per tonne of product) of Brazilian soy exports over the period 2010–2015 based on ~90,000 individual traded flows of beans, oil and protein cake identified from the municipality of origin through international markets. Soy is the most traded agricultural commodity in the world and the main agricultural export crop in Brazil, where it is associated with significant environmental impacts. We detect an extremely large spatial variability in carbon emissions across sourcing areas, countries of import, and sub-stages throughout the supply chain. The largest carbon footprints are associated with municipalities across the MATOPIBA states and Para, where soy is directly linked to natural vegetation loss. Importing soy from the aforementioned states entailed up to six times greater emissions per unit of product than the Brazilian average (0.69 t t−1). The European Union (EU) had the largest carbon footprint (0.77 t t−1) due to a larger share of emissions from embodied deforestation than for instance in China (0.67 t t−1), the largest soy importer. Total GHG emissions from Brazilian soy exports in 2010–2015 are estimated at 223.46 Mt, of which more than half were imported by China although the EU imported greater emissions from deforestation in absolute terms. Our approach contributes data for enhanced environmental stewardship across supply chains at the local, regional, national and international scales, while informing the debate on global responsibility for the impacts of agricultural production and trade.

Bioplastic production is a small but fast growing sector in the global bioeconomy that may benefit from future public support measures as governments seek to promote more sustainable consumption patterns. Here we assess the potential net economy-wide impacts of a 5% bioplastic target relative to current plastic consumption in leading producing regions. We compare two alternative policy strategies to achieve the target in a general equilibrium framework that allows for substitution between conventional and bio-based plastics: a subsidy on bioplastics vs. a tax on fossil-based plastic consumption. Our study is the first to quantify global greenhouse gas (GHG) emissions from an increased demand for bioplastics produced from conventional crops, considering both direct and indirect land use change (LUC). The tax generates a contraction of all sectors that employ plastics and hence to a 0.07% drop in global real GDP, whereas the subsidy has no significant effect on the global economy. Both policy scenarios lead to a reduction in the worldwide demand for petroleum products, by 0.08% and 0.40% respectively, although a substantial increase in the demand for sugar- and starch-based feedstock is observed, driven by the bioplastic industry. Due to direct and indirect LUC that occur at global scale, GHG emissions increase rather than decrease, by 0.96% with the subsidy and 5.01% with the tax. Trade mediated effects also generate land and GHG spillovers in countries that do not enforce the target. Results show that promoting bioplastic consumption is not effective for climate change mitigation if based on conventional biomass feedstock when emissions from LUC are taken into account, although it can contribute to oil security in the main plastic producing regions. A biomass resource base does not guarantee the sustainability of bioplastics vis-a-vis fossil-based polymers, although further assessment of potential environmental gains associated with biodegradability and recyclability is desirable.

[EN] This study assesses possible biodiesel pathways for the Spanish transport sector, representing the current situation. Life Cycle Assessment was carried out for two scenarios: Scenario 1, where 1 MJ of soybean biodiesel was imported from Argentina, and Scenario 2, where 1 MJ of biodiesel from used cooking oil (UCO) was manufactured in Spain. System expansion was performed to include the marginal products involved and additional functions were considered under a consequential approach. Scenario 1 included the production of palm oil in Malaysia (+25.27 g), as the marginal supplier in the global market. This also implied a decrease in the production of soybean meal in Brazil (-3.44 g). In Scenario 2, interactions in the global oil market led to changes in the opposite direction: the production of palm oil decreases in Malaysia (-2631 g), whereas the production of soybean meal increases in Brazil (+3.58 g). Without considering emissions from Land Use Change (LUC), UCO biodiesel produced in Spain performed better than imported biodiesel from Argentina in all the analyzed impact categories but Global Warming (GW), which was 138.9% lower in Scenario 1, mainly due to the carbon uptake by soybeans in Argentina and palm trees in Malaysia. Since these results could be misleading, GHG emissions from LUC in each country were included. Indirect functions of the expanded systems appeared to have a great contribution in the overall GW impact, especially in Scenario 2. Results show that there are clear environmental benefits arising from the use of UCO biodiesel in Spain to meet the European targets, as compared to the use of imported soybean biodiesel from Argentina. The Monte Carlo simulation for both scenarios also reinforces confidence in the comparative assessment. (C) 2014 Elsevier Ltd. All rights reserved., N. Escobar gratefully acknowledges a research contract from Generalitat Valenciana (ACIF/2010/200). The authors sincerely thank Dr. Luis Panichelli who collaborated intensely in the LCI phase by providing the data on biodiesel production in Argentina, and also helped with the interpretation of the results. They also thank Bio-norte for providing them with the data on UCO transesterification.

[EN] Right after the enforcement of the Directive (EU) 2015/1513, amending the Renewable Energy Directive of the European Union, the situation of the biodiesel sector in Spain is particularly uncertain. Although domestic biodiesel production has significantly increased since 2013, many plants are still idle, leading to an excess of capacity. This paper aims to provide an operational framework that combines Life Cycle Assessment (LCA) with economic optimization to determine the feedstock combination for domestic biodiesel production in Spain in compliance with this Directive, and quantify the associated impacts. A multi-sector, mathematical programming model is proposed in a Partial Equilibrium setting, implementing an LCA module. The optimal oil mix for the sector is highly dependent on assumptions regarding land use change in crude vegetable oil exporting countries. Increasing greenhouse gas savings thresholds enhance the use of waste oils and domestic oilseeds, while preventing deforestation of carbon-rich ecosystems; the only exception is the Brazilian Cerrado savanna. A double-counting scheme for waste oil biodiesel is necessary to make plants with second-generation technology work at full capacity, delivering further environmental benefits. Although there is room for further improvement, the model can provide very good insights for biodiesel policy analysis in the context of Spain., Authors would like to acknowledge all the farmers, agricultural cooperatives and biodiesel companies that provided economic data to build the model, as well as Generalitat Valenciana for Neus Escobar's research contract (ACIF/2010/200). The research has partially been financed by the Ministerio de Ciencia y Tecnologia of Spain and FEDER (Grant ECO2014-59067-P) and by Generalitat Valenciana (project PrometeoII/2014/005).

[EN] An LCA of the cultivation of switchgrass in the Mediterranean region of Spain is carried out, based on 2010-2013 inventory data from experimental plots of two sites, Moncofar and Orihuela. Thus, a 4-year cycle is evaluated, considering different sources of variability. The functional unit is 1 t of switchgrass (dry basis) for electricity generation. Besides typical impact categories, blue and green water consumption impacts are also addressed by using watershed-specific characterization factors. In 2010, the production in Orihuela is more input-intensive than it is in Moncofar, while the biomass yield is lower. This causes greater climate change as CO2-eq. (709.1 vs. 65.0 kg t(-1)) and greater metal depletion as Fe-eq. (8.1 vs. 1.5 kg t(-1)). In the subsequent years, the yields are higher in Orihuela, and Moncofar performs worse for some specific impact categories, mainly the toxicity-related ones, and also metal depletion as Fe-eq., but only in 2011 (2.0 vs. 1.2 kg t(-1)). Due to larger irrigation doses, the blue water impact as ecosystem-eq. water is always higher in Orihuela (e.g. in 2010, 2020 vs. 390 m(3) t(-1)). On the contrary, the green water impact, also as ecosystem-eq. water, is greater in Moncofar, except for the first year (86.8 vs. 15.2 m(3) t(-1)). Switchgrass from the two locations could be eligible for bioelectricity production in the European Union in accordance with the sustainability requirements for greenhouse gas savings. Ad hoc decisions on crop management are, however, critical to the environmental impacts, evidencing the importance of taking a multi-year approach., The research has been partially funded by the body Generalitat Valenciana through Fundacion Agroalimed, under the coordination of the Instituto Valenciano de Investigaciones Agrarias (IVIA). The authors would like to acknowledge the cooperatives Sociedad exportacion de agrios No 2 Coop. V. and Surinver for the guidance on the crop management.

Purpose This study aims to develop a model with which to build diets taking into account nutritional, climate change and economic aspects. A case study is used to test the proposed model, consisting of finding the optimal menus for school children in Spain from combinations of 20 starters, 20 main dishes and 7 desserts for a 20-day planning period. Methods An optimizing technique, specifically integer goal programming, is used as a means of designing diets which take into account the aforementioned aspects. Goal programming (GP) is used to design those menus that meet, or nearly meet, all the requirements with respect to caloric content, caloric share among macronutrients, nutrients to encourage and nutrients to limit, while reducing the carbon footprint (CFP) and the lunch budget. In order to have real, acceptable dishes, a school catering company provided information about the typical dishes they serve. The CFP of each dish was assessed, based on literature about life cycle assessment and CFP studies on food products. The nutritional value of each dish was obtained from databases, whereas prices were gathered from a wholesaler. Results and discussion After solving the goal programming model for several CFP and budget goals, the results show reductions with respect to the average CFP of between −13 and −24 %, and reductions with respect to the average budget between −10 and −15 % while maintaining the nutritional aspects similar to the average of the proposed menus. The results show that a wide range of budget is available, maintaining an almost constant CFP and meeting nutritional requirements to a similar degree; therefore, it is possible to avoid trade-offs between the CFP and the budget. The analysis of the dishes selected shows how the optimization model, in general, avoids the dishes which have a high CFP and high price and which are low in iron content, but high in protein and cholesterol. Conclusions Goal programming constitutes a suitable tool for designing diets which are economically, environmentally and nutritionally sustainable. Its flexibility enables specific issues to be studied, such as the existence of possible trade-offs between budget and CFP, attained by changing the budget and the CFP goals. By means of an iterative process, new dishes could be introduced or the existing ones could be improved, thus providing catering companies with useful information., The authors gratefully acknowledge the financial support from the Spanish Ministerio de Ciencia e Innovacion, Project CTM2010-18118.

[EN] In the last decade, there has been an increase in demand for biofuels, fostered by public policies. In the European Union, Directive 2009/28/EC (RED) establishes a 10% target for renewable energy use in the transport sector by 2020, in order to reduce overall greenhouse gas (GHG) emissions. In view of the land use change (LUC) that has recently occurred on a global scale as a consequence of bioenergy expansion, environmental considerations are more frequently incorporated into biofuel policies in order to promote only those biofuels delivering substantial GHG savings. The aim of the present thesis has been to analyze the environmental effects of the introduction of biodiesel for transport in the context of Spain, by applying different methodologies under a life cycle perspective, in order to address controversial issues, such as indirect LUC. First of all, the environmental and economic benefits brought about by an integrated process for waste management have been analyzed; biodiesel is obtained from the treatment of used cooking oil (UCO). The evaluation of the environmental performance has been carried out by means of the Life Cycle Assessment (LCA) methodology, while the financial assessment has been performed by applying a Life Cycle Costing (LCC). Both methodologies are based on a holistic approach and are crucial for a more thorough understanding of the sustainability of the proposed system. The combined study shows that the process has the potential to cause significant environmental benefits (subject to methodological assumptions), but this comes at the expense of the profits generated when the analysis is carried out from a municipal point of view. LCA has been subsequently applied to different systems for biodiesel production under a consequential approach, as the only way to measure indirect effects. There are different methodologies to carry out a consequential LCA, and all of them require the application of economic concepts. The first one consists of performing system expansion in order to include the additional functions provided by the co-products, since indirect effects arise from co-product interactions with other life cycles in the international market. This has allowed for the biodiesel domestically produced from UCO to be compared with the soybean biodiesel imported from Argentina. Furthermore, a mathematical programming model has been proposed based on the biodiesel sector's nameplate capacity in Spain. Its aim is to determine the optimal feedstock mix according to economic criteria, in order to meet the target demand for 2020; the biodiesel resulting from the mix must also fulfill the environmental requirements in the RED. The model allows for an LCA to be simultaneously carried out, in order to calculate the emissions associated with each production pathway. Indirect emissions from LUC in the Spanish agriculture can also be estimated. Finally, a general equilibrium model has been used to analyze the global environmental consequences, in terms of GHG emissions and LUC, of increasing the demand for biodiesel in the EU to meet the RED targets, in combination with recent anti-dumping measures on biodiesel imports from some specific countries. The outcomes from these studies have allowed for emission factors to be determined for different biodiesel production pathways in the Spanish market. Not only global warming has been taken into account but also other impact categories, which may be equally critical. In addition, pros and cons of the methodologies applied have been identified, depending on the goal and scope of the study; they should be applied in a complementary manner for a better understanding of the global phenomenon of bioenergy, increasing the confidence in GHG emission results. Reducing uncertainty in LUC estimates is crucial to enhance the applicability of future biofuel policies., [ES] La demanda de biocombustibles ha aumentado progresivamente en los últimos años, fomentada por políticas públicas. En la Unión Europea, la Directiva 2009/28/EC (RED) establece un objetivo del 10% para el uso de energías renovables en el sector del transporte en 2020, con tal de reducir los gases de efecto invernadero (GEI). Ante la evidencia del cambio en el uso del suelo (CUS) a escala global a consecuencia del auge de los biocombustibles, se han incorporado consideraciones ambientales para promover únicamente aquellos biocarburantes que causen un ahorro sustancial de GEI. El objetivo de la presente tesis ha sido analizar los efectos ambientales de la introducción de biodiesel en el contexto español, aplicando distintas metodologías bajo una perspectiva del ciclo de vida, con el fin de abordar cuestiones controvertidas como el CUS indirecto. En primer lugar, se han evaluado los beneficios ambientales y económicos derivados de un proceso integrado de tratamiento de residuos donde se produce biodiesel a partir de aceite de cocina usado (ACU). La evaluación ambiental se ha realizado mediante la metodología de Análisis de Ciclo de Vida (ACV), mientras que la evaluación financiera se ha llevado a cabo mediante el cálculo del Coste del Ciclo de Vida. Ambas metodologías comparten el mismo enfoque holístico y son esenciales para una comprensión más completa de la sostenibilidad del sistema propuesto. El análisis combinado revela que, si bien éste presenta el potencial de generar importantes beneficios ambientales (sujeto a supuestos metodológicos), esto ocurre a costa del beneficio económico cuando el análisis se hace desde el punto de vista municipal. A continuación, se ha aplicado el ACV a distintos sistemas de producción de biodiesel bajo un enfoque consecuencial, como la única forma de estimar el CUS indirecto. Existen diferentes metodologías para la realización de un ACV consecuencial y todas ellas requieren la aplicación de conceptos económicos. La primera consiste en aplicar la expansión del sistema para incluir las funciones adicionales desempeñadas por los coproductos, ya que los efectos indirectos surgen de las interacciones de éstos con otros ciclos de vida en el mercado internacional. Ello ha permitido comparar la producción de biodiesel de ACU frente a la importación de biodiesel de soja de Argentina. Se ha propuesto también un modelo de programación matemática basado en la capacidad nominal del sector del biodiesel en España. Su objetivo es determinar la combinación de materias primas óptima, desde el punto de vista económico, para cumplir con de la demanda proyectada para 2020 pero que cumpla a su vez con las exigencias ambientales de la RED. El modelo incorpora un módulo para realizar un ACV de forma simultánea, que permite estimar las emisiones asociadas a las distintas vías de obtención de materias primas. Se pueden calcular incluso las emisiones indirectas por CUS en la agricultura española. Finalmente, se ha aplicado un modelo de equilibrio general para el análisis de las consecuencias ambientales globales (en términos de emisiones de GEI y CUS) de un aumento en la demanda de biodiesel en la UE según la RED, en combinación con las recientes medidas arancelarias sobre las importaciones de determinados países. Todo ello ha permitido calcular factores de emisión para diferentes alternativas de producción de biodiesel destinado al mercado español, no sólo en relación al calentamiento global sino también a otras categorías de impacto que pueden ser igualmente críticas. Además, se han identificado ventajas e inconvenientes de las metodologías aplicadas, dependiendo del objetivo y el alcance de estudio; lo ideal es aplicarlas de forma complementaria para una mayor comprensión del fenómeno global de la bioenergía, contribuyendo a una mayor solidez en los resultados de GEI. Reducir la incertidumbre en las estimaciones de CUS es fundamental para asegurar la a, [CAT] La demanda de biocombustibles ha augmentat progressivament els darrers anys, fomentada per polítiques públiques. En la Unió Europea, la Directiva 2009/28/EC (RED) estableix un objectiu del 10% per a l'ús d'energies renovables en el sector del transport en 2020, amb l'objectiu de reduir els gasos d'efecte hivernacle (GEH). Davant l'evidència del canvi en l'ús del sòl (CUS) a escala global a conseqüència de l'auge dels biocombustibles, s'han incorporat consideracions ambientals per promoure únicament aquells biocarburants que causen un estalvi substancial de GEH. L'objectiu de la present tesi ha estat analitzar els efectes ambientals de la introducció de biodièsel en el context espanyol, mitjançant l'aplicació de diferents metodologies sota una perspectiva del cicle de vida, amb la finalitat d'abordar qüestions tan controvertides com el CUS indirecte. En primer lloc, s'han avaluat els beneficis ambientals i econòmics derivats d'un procés integrat de tractament de residus on es produeix biodièsel a partir d'oli de cuina usat (OCU). L'avaluació ambiental s'ha realitzat mitjançant la metodologia d'Anàlisi de Cicle de Vida (ACV), mentre que l'avaluació financera s'ha dut a terme mitjançant el càlcul del Cost del Cicle de Vida. Ambdues metodologies comparteixen el mateix enfocament holístic i són essencials per a una comprensió més completa de la sostenibilitat del sistema proposat. L'anàlisi combinada revela que, si bé aquest presenta el potencial de generar importants beneficis ambientals (subjecte a supòsits metodològics), això ocorre a costa del benefici econòmic quan l'anàlisi es fa des del punt de vista municipal. A continuació, s'ha aplicat l'ACV a diferents sistemes de producció de biodièsel sota un enfocament conseqüencial, com l'única forma d'estimar el CUS indirecte. Existeixen diferents metodologies per a la realització d'un ACV conseqüencial i totes elles requereixen l'aplicació de conceptes econòmics. La primera consisteix a aplicar l'expansió del sistema per incloure les funcions addicionals exercides pels coproductes, ja que els efectes indirectes sorgeixen de les interaccions d'aquests amb altres cicles de vida al mercat internacional. Això ha permès comparar la producció de biodièsel d'OCU amb la importació de biodièsel de soia de l'Argentina. S'ha proposat també un model de programació matemàtica basat en la capacitat nominal del sector del biodièsel a Espanya. El seu objectiu és determinar la combinació òptima de matèries primeres, des del punt de vista econòmic, per complir amb de la demanda projectada per 2020 però que complisca al seu torn amb les exigències ambientals de la RED. El model incorpora un mòdul per realitzar un ACV de forma simultània, el qual permet estimar les emissions associades a les diferents vies d'obtenció de matèries primeres. Es poden calcular fins i tot les emissions indirectes per CUS en l'agricultura espanyola. Finalment, s'ha aplicat un model d'equilibri general per a l'anàlisi de les conseqüències ambientals globals (en termes d'emissions de GEH i CUS) d'un augment en la demanda de biodièsel en la UE segons la RED, en combinació amb les mesures aranzelàries recents sobre les importacions des de determinats països. Tot això ha permès calcular factors d'emissió per a diferents alternatives de producció de biodièsel destinat al mercat espanyol, no només en relació a l'escalfament global sinó també a altres categories d'impacte que poden ser igualment crítiques. A més, s'han identificat avantatges i inconvenients de les metodologies aplicades, depenent de l'objectiu i l'abast d'estudi; l'ideal és aplicar-les de forma complementària per a una major comprensió del fenomen global de la bioenergia, per contribuir a una major solidesa en els resultats de GEH. Reduir la incertesa en les estimacions de CUS és fonamental per assegurar l'aplicabilitat de les polítiques de biocombustibles en el futur., Escobar Lanzuela, N. (2015). Contribution to the environmental impact assessment of biodiesel in the context of Spain [Tesis doctoral]. Editorial Universitat Politècnica de València. doi:10.4995/Thesis/10251/52027., TESIS

[EN] The goal of this study is to analyze the economic performance of an alternative system for waste management proposed by the European Integral-b project. Its aim is to treat both used cooking oil (UCO) and solid organic waste (SOW) from the hospitality sector by biodiesel production and anaerobic digestion, respectively. A cogeneration engine adapted to use glycerol as a fuel is implemented. These results complement others from a previous life cycle assessment (LCA). The system proposed (scenario A) is compared to a system consisting of average waste management options (scenario B) by means of life cycle costing (LCC). The functional unit (FU) is the amount of UCO and SOW from hospitality produced per person and year in Spain. The profits generated by the FU under the two scenarios are calculated from a financial point of view. It is assumed that co-products from both scenarios translate into revenues for waste managers. Scenario analysis assesses different rates for the electricity output, subject to market regulations, and different levels of UCO availability. Monte Carlo simulations are carried out to analyze parameter and price uncertainty. The profits in all the scenarios are negative, and those of scenario A are lower than those of scenario B under all the scenario formulations. Scenario A generates greater income than scenario B but also higher expenses, mainly due to SOW collection. The new electricity rates are detrimental for the financial performance of the Integral-b since the overall profits mostly depend on the sale of electricity. Readier UCO availability benefits both scenarios to a similar extent. The uncertainty analysis reinforces the comparative results, although there is some likelihood scenario A will generate greater profits. The sensitivity analysis allows for the key parameters to be identified in order to optimize the process further. Possible trade-offs between the LCC and LCA results have been evaluated. Results from the financial analysis show that the Integral-b process delivers greater losses as compared to a reference scenario. Both generate net costs, meaning that stakeholders have to finance the functions provided. Uncertainty in the electricity regulations constitutes an obstacle for such projects as these to be implemented. As in LCA, the definition of the system boundaries and FU is critical in LCC., The authors acknowledge all the Integral-b partners and also the Generalitat Valenciana for providing the funds for N. Escobar's research contract (ACIF/2010/200) and for the financial support under the project PrometeoII/2014/005.

[EN] Purpose The goal of this study is to analyze the environmental improvement brought about by an alternative system for waste management proposed by the Integral-b project, funded by the European Union (EU). Its aim is to treat both used cooking oil (UCO) and organic waste from the restaurant and catering sector in Spain, by biodiesel production and anaerobic digestion, respectively. A cogeneration engine adapted to use glycerin as a fuel is implemented. Methods The functional unit (FU) is the management of the UCO and organic waste from restaurants and catering produced per person and year in Spain. The system proposed (scenario A) is compared to a system consisting of the prevailing management options for the same kind of waste (scenario B). Apart from including biodiesel production from the UCO, this reference scenario assumes that the organic waste is allocated to different streams, according to Spanish statistics. The systems under study generate different coproducts and as such are complex; therefore, system expansion is performed. Different scenario formulations are set to analyze the influence of assumptions regarding co-product credits in the results. Finally, Monte Carlo simulations are carried out to analyze parameter uncertainty. Results and discussion The environmental benefits caused by scenario A are conditional on the choices regarding coproduct credits. Scenario A causes a reduction of the impact (43-655 %) in most of the scenario formulations when the current levels of UCO collection are considered. However, when higher levels of UCO collection are taken into account for the definition of the FU, scenario B performs better for half of the scenario formulations, due to the increase in the environmental credits from glycerin production. The only impact categories for which scenario A performs unconditionally better than scenarioBare global warming and photochemical ozone creation. Parameter uncertainty appears to influence the comparative results to a lesser extent, mainly caused by the parameters involved in avoided processes. Conclusions Although system expansion appears as an option for dealing with the multifunctionality of waste management processes, uncertainty caused by choices must be assessed. Under our scenario assumptions, re-using the glycerol in the system proposed by Integral-b can be detrimental, and the reference scenario results in higher avoided burdens in some scenario formulations. Including glycerin valorization in scenario B should be considered if the biodiesel production keeps increasing in Spain. Analyzing parameter uncertainty helps to provide reliable results., The authors would like to acknowledge the Generalitat Valenciana for the finantial support (PrometeoII/2014/005), and for providing the funds for N. Escobar's research contract (ACIF/2010/200). They would also like to thank all the Integral-b partners for cooperating closely and making this study possible.