Estudo de viabilidade econômica e socioambiental do etanol super-hidratado como combustível para mobilidade e geração de energia

Abstract

Fossil fuels (gasoline and diesel) are largely used as primary energy source for mobility and stationary power generation. Meanwhile, their use has a negative impact on Greenhouse Gas (GHG) emission, and maintains the energy dependency of non-renewable and pollutant sources. In this context, biofuels (ethanol and biodiesel, for example) are feasible alternatives that provide benefits such as the natural resources preservation and GHG mitigation. In Brazil, ethanol (a blend of 94% ethanol and 6% water) is the main marketed biofuel, produced from sugarcane, because it has climate and technologies suitable for its cultivation. Distillation and dehydration are among the ethanol production steps, where the water is gradually removed from solution, increasing the final concentration of ethanol. Because of the physical conditions of the mixture, energy consumption for this production process increases drastically as long as more ethanol in water is deserved (above 80%). For this, ethanol production process become more onerous in comparison to the production of less noble ethanol-water mixtures, as 80% and 70% of ethanol. Therefore, based in this current disadvantage of the ethanol obtaining process, the present research explored the economic feasibility of more diluted ethanol-water mixtures, referred as super-hydrous ethanol, in order to reduce fuel production costs, improving its competitiveness in relation of fossil fuels, currently used for mobility and power generation. Through a bibliographical and documental research about the theme, data referred to super-hydrous ethanol production and transportation costs were analyzed. A survey was applied to ethanol experts, in order to rank the critical success factors in a viability of super-hydrous ethanol. Also, MCDA were used, specifically Fuzzy Analytic Hierarchy Process (FAHP), in order to evaluate the impact of higher water concentration in the super-hydrous ethanol chain, especially about the logistics in Brazilian territory. Using this MCDA, uncertainness is reduced about the analyzed criteria, hierarchizing them, in order to evaluate the viability of super-hydrous ethanol. As a result, it was concluded that technical and financial criteria were the most relevant to analyze the feasibility of super-hydrous ethanol.