Environmental sustainability of biobased products : new assessment methods and case studies

Certain environmental issues, as climate change and the depletion of fossil fuels, gave support to the renaissance of a biobased economy, where products are to be produced mainly from biomass (so-called biobased products). However, biobased products do not automatically mean environmentally sustainable products. In this sense, a proper evaluation of the environmental impacts of biobased products has to be done, through environmental assessment methodologies that consider the life-cycle perspective. In Chapter 1 several environmental assessment methodologies were discussed. Among them, life cycle assessment (LCA) appeared to be the most predominant, but it still has some scientific gaps, as lack of spatial-differentiation and proper evaluation of land use impacts. Other environmental assessment methodologies, so-called resource accounting methodologies (RAM), which are based on the life-cycle perspective and focused on accounting for the cumulative resource used/consumed, appeared to be promising. Nevertheless, they also have specific scientific gaps, as land resource accounting. In Chapter 2 we introduced a new method to account for land resources through exergy in life cycle assessment. It partitioned the resource accounting methodology in two approaches. For natural systems it was based on the chemical exergy content of the biomass extracted. For human-made systems, it was based on the exergy value of the potential natural net primary production deprived due to human land use. For the latter, spatial-differentiated characterization factors were created. In Chapter 3, the results from Chapter 2 were coupled with a traditional RAM (CEENE), and a new indicator for natural resource balance of terrestrial biomass was created (ΔEP). This indicator was compared to traditional resource balance indicators (e.g. net energy value) through agricultural case studies and presented better results regarding completeness in resources accounting. In Chapter 4 and 5 the environmental sustainability of bioethanol-based PVC was assessed, through attributional and consequential LCA, respectively. The results of Chapter 4 showed that bioethanol-based PVC has better results than its fossil reference for specific environmental impact categories (climate change and non-renewable resources) and as a single score result (through the LCIA methodology 'Recipe Endpoint H/A‘). In Chapter 5 we included the effects on indirect land use change (iLUC) in the environmental assessment. The results showed that bioethanol-based PVC can still have better results, as long as the iLUC is limited to a certain value, for instance less than 5.7% of the area of sugarcane cultivation. In Chapter 6 we analyzed the environmental sustainability of two possible uses for the Brazilian ethanol, i.e., as fuel for transportation or as feedstock for the chemical industry (ethylene). The latter appeared to cause more environmental gains for climate change and fossil energy consumption, as long as the ethanol-to-ethylene yield was 100%. The results of this PhD were able to give contributions to the scientific community in two issues. First, through the creation of new methods and indicators, it was able to fill some scientific gaps of environmental assessment methodologies, mainly regarding spatial-differentiation and land resource accounting. Second, it was able to give information of the environmental sustainability of specific biobased products through LCA. Nevertheless, these results left opportunities for future challenges, discussed in chapter 7

Avaliação de métodos de AICV: um estudo de caso de quatro cenários de ração para frangos de corte

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Ambiental, Florianópolis, 2010A metodologia de avaliação do ciclo de vida (ACV), cujo uso vem crescendo bastante nos últimos anos, inclui uma etapa de avaliação de impacto do ciclo de vida (AICV). Existem diversos métodos de AICV já desenvolvidos, entre eles os holandeses Eco-indicator 99 e CML. Além destes, há alguns métodos mais emergentes, como a Pegada Ecológica e a Pegada de Carbono. A primeira, desenvolvida por Wackernaegel e Rees na década de 1990, foi inicialmente criada para avaliar países, regiões e pessoas, e nos últimos anos vem crescendo seu uso em produtos. A quantificação de emissão de gases de efeito estufa (GEE) em organizações e países já existe há algum tempo e nos últimos anos a Pegada de Carbono vem sendo usada para esse fim em produtos. O objetivo deste estudo é comparar os quatro métodos de AICV citados, qualitativa e quantitativamente. A primeira modalidade de comparação foi feita baseada em seis critérios e a partir de leitura das bibliografias base desses métodos. A comparação quantitativa foi feita realizando a ACV de quatro cenários de produção de ração para frangos de corte. Com as duas análises foi possível observar que o Eco-indicator 99 é vantajoso ao utilizar um grande número de categorias de impacto ambiental, porém apresenta maior subjetividade e unidades de difícil compreensão ao público-alvo. O CML possui a mesma vantagem do método anterior, porém não apresenta procedimentos de agregação, dificultando a decisão entre sistemas. A Pegada Ecológica tem a vantagem de ser um método mais auto-explicativo, no entanto, assim como a Pegada de Carbono, apresenta a desvantagem de usar poucas categorias de impacto ambiental. Pôde-se concluir por este trabalho que métodos de AICV diferentes podem levar a resultados de ACV distintos. Deste modo, ressalta-se a importância de se conhecer a fundo o método antes de utilizá-lo, inicialmente para escolher aquele que atenda as necessidades do estudo, mas também para poder justificar alguns resultados discrepantes e estimar impactos negligenciados. Uma proposta interessante seria realizar estudos de ACV com mais de um método de AICV, auxiliando numa tomada de decisão mais confiável.The life cycle assessment (LCA) methodology, whose use has grown greatly in recent years, includes a life cycle impact assessment (LCIA) stage. There are several LCIA methods already developed, including the Dutch Eco-indicator 99 and CML. Besides these, there are some other promising methods, such as the Ecological Footprint and Carbon Footprint. The first, created by Wackernaegel and Rees in the 1990s, was initially developed to assess countries, regions and people, and in recent years its use in products has been increased. The quantification of greenhouse gases (GHG) emissions by countries and organizations existed for some time and in the last years Carbon Footprint has been used for this on product assessment. The objective of this study is to compare these four LCIA methods, qualitatively and quantitatively. The first type of comparison was carried out based on six criteria and from reading these methods# base literatures. A quantitative comparison was made by performing the LCA of four scenarios for the production of chicken feed. In both comparisons it was observed that the Eco-indicator 99 is advantageous because it uses a large number of environmental impact categories, but it has more subjectivity and its units are difficult to understand for the target audience. The CML has the same advantage of the previous method, but has no aggregation procedure, making the decision between systems difficult. Ecological Footprint has the advantage of being a more self-explanatory method, however, as Carbon Footprint, it has the disadvantage of using few environmental impact categories. It was concluded by this work that using different LCIA methods lead to different LCA results. Thus, it emphasizes the importance of knowing the strengths and weaknesses of the method before using it, initially to choose one that meets the needs of the study, but also to justify some conflicting results and estimate neglected impacts. An interesting proposal would be to perform LCA studies with more than one LCIA method, as it is already being done by several authors

Toward a systematized framework for resource efficiency indicators

The transition toward resource efficient production and consumption patterns is currently one of the main challenges in engineering, environmental science and especially in governmental policies. This transition has led to a proliferation of meanings related to the resource efficiency concept, resulting in a wide variety of indicators. In this paper, we propose a systematized framework in which resource efficiency indicators can be structured and comprehensively positioned. The aim is to provide a proper understanding of the scope and limitations of particular existing resource efficiency indicators in order to assist policy makers and the scientific community in the application and further development of indicators. This framework covers all different resource use-related aspects evaluated in existing approaches, including simple accounting of resource extraction and use; environmental impact assessment due to resource extraction and use; accounting and environmental impact assessment of specific processes and of full supply chains; analyses at micro-scale and macro-scale; and analysis of both natural resources versus waste-as-resources. To illustrate the potential application of the framework, a set of currently used indicators was selected, whereupon these indicators were structured and evaluated within the framework

Classifying resource efficiency indicators based on LCA practices

Our whole society depends on the use of natural resources. Despite the fact that most natural resources are limited, they are not always used in a sustainable way. To monitor the transition towards a more resource efficient society, a wide variety of indicators has been developed over the years, both within a policy context and an industrial context. However, these indicators are not univocally defined, which generates confusion about the real meaning of resource efficiency. Indeed, the term resource efficiency is interpreted in different ways: from the simple accounting of resource extraction to environmental impact assessment related to resource availability and provision of resources ; from the micro-level of products and companies to the macro-level of regions and countries ; from a gate-to-gate perspective to a life cycle perspective or from a national perspective1 to a global perspective . Also the considered resource range (which natural resource types are taken into account) and the used quantification metric (monetary or physical) can vary from indicator to indicator. Another issue is the provenience of resources: in some studies is referred to natural resources, while in others waste is also considered to be a potential resource . This paper tries to bring order into these different visions by proposing a systematized framework for resource efficiency indicators based on LCA practices. The proposed framework is subdivided in multiple levels based on the interpretations summarized above. The use of the framework is illustrated by structuring several resource efficiency indicators in practice today, e.g. the GDP over DMC (Gross Domestic Product over Domestic Material Consumption), used within a policy context, or process-efficiency, used within an industrial context. Within this framework, resource efficiency indicators can be classified and critically evaluated, identifying possibilities for further development and improvement

Abiotic resource use in life cycle impact assessment : part II : Linking perspectives and modelling concepts

Starting from a lack of consensus on how to consistently assess abiotic resource use in life cycle assessment, a structured approach was developed to enable a classification of perspectives on resource use, based on the socalled role of resources. Using this classification, this paper focusses on analysing links between perspectives and modelling concepts, i.e. the conceptual implementation. To analyse the modelling concepts for a selection of existing LCIA methods and other modelling approaches, the concept of the system model is introduced. It defines the relevant inventory flows to be assessed by the LCIA method, and, at the same time, to be considered in the characterization model, and how the flows and stocks of resources used to calculate the characterization factors are positioned in relation to environment (nature) and economy (technosphere). For consistency, they should be aligned with the position of inventory flows and, at the same time, reflect the perspective on resources taken by the method. Using this concept, we critically review a selection of methods and other modelling approaches for consistency with the perspectives on resource use, as well as for their internal consistency. As a result of the analysis, we highlight inconsistencies and discuss ways to improve links between perspectives and modelling concepts. To achieve this, the new framework can be used for the development or improvement of LCIA methods on resource use

Abiotic resource use in life cycle impact assessment : part I : towards a common perspective

At the beginning of the SUPRIM project, there was no global consensus on the assessment of impacts from the use of abiotic resources (minerals and metals), in life cycle impact assessment (LCIA). Unlike with other impact categories such as global warming, there is not just one single, explicitly agreed-upon problem arising from the use of abiotic resources. The topic is complex and new methods are still being developed, all with different perspectives and views on resource use. For this reason, the SUPRIM project initiated a consensus process together with members from the research and mining communities, with the aim to obtain an understanding of different stakeholders’ views and concerns regarding potential issues resulting from the use of resources. This paper reports on this consensus process and its outcomes. Insights from this process are twofold: First, the outcome of the process is a clear definition of the perspectives on abiotic resources which form the starting point to further refine or develop LCIA methods on abiotic resource use. Second, the process itself has been a challenging but valuable exercise, which can inspire the evolution of other complex issues in life cycle impact assessment, where research communities face similar issues as experienced with abiotic resources (e.g. water and land use, social LCA, etc.)

Evaluation of characterization models for the photochemical smog impact category focused on the Brazilian reality = Avaliação de modelos de caracterização para a categoria de impacto smog fotoquímico voltada à realidade brasileira = Evaluación de modelos de caracterización para la categoría de impacto smog fotoquímico enfocado en la realidad brasileña

The Life Cycle Impact Assessment (LCIA) is composed of characterization models, and in Brazil, the methodological and scientific LCIA framework is still under development. The research’s aim was to evaluate the literature available characterization models to photochemical smog category. Thus, the contribution of work is recommending one of these models to be used in Brazilian LCA studies, standardizing the studies in Brazil. The methodology consisted of searching the literature and selecting, describing and analyzing the characterization models as well as elaborating a table of criteria for better comparison. Aiming to visualize the differences in the results of each selected model, a case study was applied to analyze the photochemical smog formation potential to the transport of one ton of sugar using two transportation modes (road and railroad). Five characterization models related to smog category were selected, described and compared. Herewith, it was observed that the models present significant differences, that is, each model presents Characterization Factors (CF) for different categories within the environmental impact chain of the photochemical smog (midpoint and/or endpoint), differences in modeling, scale of the model (regional, continental or global), quantity and quality of elementary flows, etc. Those factors have influence in the CF’s calculation and, consequently, the LCA’s results, in the same case study. The criteria table’s results suggested that the model of Van Zelm et al. (2016) – World (midpoint and endpoint), is the best interim option to be used in studies of LCA in Brazil, because it was the model that resulted in the highest grade referring to the established criteria and it presents results on a Global scale. However, the results do not rule out the need for regionalization studies, which would develop a model that presents results and studies directed to the Brazilian reality or adjust the model of Van Zelm et al. (2016) - Brazil.La Evaluación de Impacto del Ciclo de Vida (EICV) se compone de modelos de caracterización, y en Brasil, la estructura metodológica y científica de la EICV está en desarrollo. El objetivo de esta investigación fue evaluar los modelos de caracterización para la categoría de impacto smog fotoquímico presentes en la literatura. Por lo tanto, la contribución del trabajo es recomendar uno de estos modelos para ser utilizado en estudios brasileños de ECV, estandarizando estudios en Brasil. La metodología consistió en la investigación en la literatura y selección, descripción y análisis de los modelos de caracterización, así como en la elaboración de una tabla de criterios para una mejor comparación. Con el objetivo de visualizar las diferencias en los resultados de cada modelo seleccionado, se usó un estudio de caso para analizar el potencial de formación de smog fotoquímico del transporte de una tonelada de azúcar usando dos modales de transporte (carretera y ferrocarril). Después de la investigación, cinco modelos de caracterización relacionados con la categoría de impacto smog fueron seleccionados, descritos y comparados. Con ello, se observó que los modelos difieren significativamente, o sea, cada modelo presenta Factores de Caracterización (FC) para diferentes categorías dentro de la cadena de impacto ambiental del smog fotoquímico (punto medio y/o punto final), diferencias en el modelado, en la escala del modelo (regional, continental o global), en la cantidad y calidad de los flujos elementales, etc. Estos factores influyen en el cálculo del FC y, consecuentemente, en los resultados de una ECV, para un mismo estudio de caso. Los resultados de la tabla de criterios sugieren el modelo de Van Zelm et al. (2016) - Global (punto medio y/o punto final), como una buena opción provisional para ser utilizado en los estudios de ECV en Brasil, pues éste fue el modelo que resultó en la mayor nota referente a los criterios establecidos, presentando resultados en escala global. Sin embargo, los resultados no descartan la necesidad de estudios de regionalización, volcados a la realidad brasileña. Otra posibilidad apuntada es la ampliación y ajuste del modelo de Van Zelm et al. (2016) - Brasil.A Avaliação de Impacto do Ciclo de Vida (AICV) é composta por modelos de caracterização e, no Brasil, a estrutura metodológica e científica da AICV está em desenvolvimento. O objetivo desta pesquisa foi avaliar os modelos de caracterização para a categoria de impacto smogfotoquímico presentes na literatura. Assim, a contribuição do trabalho é recomendar um destes modelos para ser utilizado em estudos brasileiros de ACV, padronizando os estudos no Brasil. A metodologia consistiu de pesquisa na literatura e na seleção, descrição e análise dos modelos de caracterização, como também na elaboração de uma tabela de critérios para melhor comparação. Com o objetivo de visualizar as diferenças nos resultados de cada modelo selecionado, um estudo de caso foi aplicado para analisar o potencial de formação de smog fotoquímico do transporte de uma tonelada de açúcar usando dois modais de transporte (rodoviário e ferroviário). Após a pesquisa, cinco modelos de caracterização relacionados a categoria de impacto smog foram selecionados, descritos e comparados. Com isso, observou-se que os modelos apresentam diferenças significativas, ou seja, cada modelo apresenta Fatores de Caracterização (FC) para diferentes categorias dentro da cadeia de impacto ambiental do smog fotoquímico (ponto médio e/ou ponto final), diferenças na modelagem, na escala do modelo (regional, continental ou global), na quantidade e qualidade dos fluxos elementares, etc. Esses fatores influenciam no cálculo do FC e, consequentemente, nos resultados de uma ACV, para um mesmo estudo de caso. Os resultados da tabela de critérios sugerem o modelo de Van Zelm et al. (2016) -Global (ponto médio e ponto final), como uma boa opção provisória a ser utilizado em estudos de ACV no Brasil, pois este foi o modelo que resultou na maior nota referente aos critérios estabelecidos, sendo que apresenta resultados em escala Global. Entretanto, os resultados não descartam a necessidade de estudos de regionalização, voltados à realidade brasileira. Outra possibilidade apontada é a ampliação e ajuste do modelo de Van Zelm et al. (2016) -Brasil.Palavras-chave: Avaliação do Ciclo de Vida.Avaliação de Impacto do Ciclo de Vida.Métodos de AICV.Ozônio troposférico.Fatores de Caracterização.Regionalização de modelos