The objective of this dissertation is to analyze the economic impact of newly operational ethanol biorefineries on rural counties in the U.S. Midwest region for the period 2001 to 2015 using a quasi-experimental approach. Rapid growth in the ethanol industry expanded the number of ethanol plants located in the U.S. Midwest from 54 in 2001 to 173 in 2015. Out of the counties with 119 new ethanol biorefineries, 97 counties met the general treatment criteria defined in this dissertation, but only 56 of those counties qualified for the rural treatment criteria. Counties with ethanol biorefineries that qualified for treatment were organized into a treated group based on county level data. Six counterfactual control groups (or control counties without ethanol biorefineries) were contemporaneously matched to the treated counties based on the Mahalanobis distance metric evaluated on a set of 29 selection variables. Matching occurred on two levels. In the first level, matching was performed both for the in-state level and over the entire Midwest region. In the second level, three criteria were used to select the final control groups: Mahalanobis distance metric best match, population best match, and rural-urban continuum codes (RUCC) best match. Economic impact is evaluated based on the growth rate in real per capita earnings for the treated group over a period from one to five years after treatment relative to the control group. A difference-in-differences (DID) model is used to assess the significance of results where the dependent variable is the natural log of real per capita earnings and a set of control variables is used to capture state fixed effects, time fixed effects and spillover effects. Empirical results evaluated against a representative Midwest control group and over six regression models adjusting for various fixed effects produced, on average, one-sided significant results for average treatment on the treated (ATOT) with a (min, max) range of growth rates as (5.53%-7.63%), (10.0%-12.0%), (14.7%-19.6%), (14.5%-18.3%), and (13.3%-18.9%) from one to five years after treatment, respectively. The minimum value of these estimates can be represented as an uncorrected average annual growth rate as 2.75%, 3.33%, 3.68%, 2.90%, and 2.22% over the respective period from one to five years after treatment. Employment levels for the treated group increased on average by 211 at the county level five years after treatment. A comparative Midwest control group lost, on average, 169 jobs over the five year period after treatment. A treated county employment multiplier calculated using the direct, indirect and induced employment impacts varied from 1.46 during the year of treatment to 7.6 five years after treatment relative to the control group. Five years after treatment, the treated group employment rate gradually increased, on average, by 2.2% which was better than either of the two counterfactual control groups used in this comparison. Overall, the analysis presented in this dissertation does show statistically significant positive economic impacts, on average, for rural U.S. Midwest counties with newly operational ethanol biorefineries relative to control counties without an ethanol biorefinery. These results demonstrate that the Renewable Fuel Standard (RFS) contributed to positive rural economic development impacts in treated counties with the possibility of spillover effects positively affecting contiguous counties.

Na atualidade, a geração de eletricidade e a produção de etanol de segunda geração a partir de materiais lignocelulósicos se apresentam como uma alternativa de desenvolvimento tecnológico no setor sucroenergético. Não obstante, a introdução de novos processos produtivos representa um verdadeiro desafio devido à complexidade e diversidade das rotas tecnológicas alternativas que podem ser avaliadas. Além disso, existem fatores econômicos e ambientais, que devem ser considerados durante o desenvolvimento e consolidação destas novas configurações. Nesse sentido, o presente trabalho tem como objetivo desenvolver uma metodologia para realizar a hierarquização exergética e exergo-ambiental de processos para obtenção de etanol e eletricidade a partir da cana-de-açúcar em distintas configurações de biorrefinarias. Para este fim, dados técnicos de operação foram adotados nas rotas tecnológicas envolvidas, bem como os aspectos ambientais da utilização destes sistemas. Os modelos propostos avaliaram as rotas Convencional (Caso 1), Bioquímica (Caso 2) e Termoquímica (Caso 3), utilizando programas de simulação e ferramentas matemáticas para simular estes processos. Ainda, a integração dos processos e diferentes usos para o bagaço excedente foram estudados, junto com diversos métodos de pré-tratamento visando à otimização e hierarquização destas rotas. O resultado final indicou configurações ótimas que permitiram a hierarquização em termos do índice exergético de renovabilidade dos processos de produção das rotas analisadas. Desse modo a rota convencional otimizada apresentou a máxima eficiência exergética dos processos e, por tanto, o menor custo exergético unitário médio das plataformas avaliadas. Ao passo que a rota bioquímica foi o sistema que promoveu um incremento de 28,58 % e 82,87 % na produção de etanol, quando comparado com o Caso 1 e o Caso 3, respectivamente. Além disso, a rota termoquímica apresentou a configuração com a maior taxa de geração de eletricidade excedente (214,98 kWh/TC). Em relação aos resultados do impacto ambiental das rotas tecnológicas, encontrou-se que a configuração mais sustentável foi a plataforma bioquímica, apresentando as menores taxas de emissões globais de CO2 (131,45 gCO2/MJ produtos). / Currently, electricity generation and second-generation bioethanol production from lignocellulosic materials represent technological alternatives in the sugar-energy sector. Nevertheless, the introduction of new production processes represents a real challenge due to the complexity and diversity of the technological routes that can be evaluated. In addition, there are economic and environmental factors that must be considered during the development and consolidation of these new configurations. Accordingly, this project aims to develop a methodology to perform the exergy and exergo-environmental analysis, evaluation and ranking of processes in order to obtain ethanol and electricity from sugarcane in different biorefinery configurations. Hence, operating technical data of each technological route were adopted as well as the environmental aspects of using these systems. The proposed models assessed the Conventional (Case 1), Biochemical (Case 2) and Thermochemical (Case 3) routes using simulation programs and mathematical tools to simulate the ethanol production and electricity generation. Furthermore, the process integration and different uses for the excess bagasse were studied with various pretreatment methods aiming the optimizing and ranking of routes. The results indicated optimal settings that allowed the ranking in terms of the environmental exergy indicator \"renewability\" of the production processes for analyzed routes. In this way, the optimized conventional route presented the maximum exergy efficiency of the processes, therefore the lowest exergetic cost average of the evaluated platforms. While the biochemical route was the system that promoted an increase of 28.58 % and 82.87% in the ethanol production, when compared to Case 1 and Case 3, respectively. In addition, the thermochemical route presented the configuration with the highest power generation rate exceeding (214.98 kWh/TC). Concerning, the environmental impact results, it was found that the most sustainable configuration was the biochemical platform, which presented the lowest overall CO2 emissions rates (131.45 gCO2/MJ products).

Renewability and the carbonaceous basis of biomass provide potential for both energy and chemical production in biorefineries in a fashion similar to crude oil refineries. Biorefineries are envisaged as having a key role in the transition to a more sustainable industry, especially as a means to mitigate greenhouse gas (GHG) emissions. A biorefinery is a concept for the flexible, efficient, cost-effective and sustainable conversion of biomass through a combination of process technologies into multiple products. This implies that biorefineries must be integrated through designs that exploit the interactions between material and energy streams. The wide range of possibilities for biomass feedstock, processes and products poses a challenge to biorefinery design. Integrating biorefineries within evolving economic and environmental policy contexts requires careful analysis of the configurations to be deployed from early in the design stage. This research therefore focuses on the application and development of methodologies for biorefinery design encompassing process integration tools, economic and environmental sustainability analyses together. The research is presented in the form of papers published or submitted to relevant peer-reviewed journals, with a preamble for each paper and a final synthesis of the work as a whole. In a first stage, mass pinch analysis was adapted into a method for integration ofbiorefineries producing bioethanol as a final product and also utilising bioethanol asa working fluid within the biorefinery. The tool allows targeting minimum bioethanol utilisation and assessing network modifications to diminish revenue losses. This new application could stimulate the emergence of similar approaches for the design of integrated biorefineries. The thesis then moves to combine feedstock production models, process simulations in Aspen Plus® and process integration with LCA, to improve energy efficiency and reduce GHG emissions of biorefineries. This work, presented via two publications covering wheat to bioethanol and Jatropha to biodiesel or green diesel, provided evidence of the benefits of biorefinery integrationfor energy saving and climate change adaptation. The multilevel modelling approach is then further integrated into a methodologydeveloped for the combined evaluation of the economic potential and GHG emissions saving of a biorefinery from the marginal performances of biorefineryproducts. The tool allows assessing process integration pathways and targeting forpolicy compliance. The tool is presented via two further publications, the first drawing analogies between value analysis and environmental impact analysis inorder to create the combined Economic Value and Environmental Impact (EVEI)analysis methodology, the second extending this to demonstrate how the tool canguide judicious movement of environmental burdens to meet policy targets. The research embodied in this thesis forms a systematic basis for the analysis andgeneration of biorefinery process designs for enhanced sustainability. The toolspresented will facilitate both the implementation of integrated biorefinery designsand the cultivation of a community of biorefinery engineers for whom suchintegrated thinking is their distinctive and defining attribute.