Analyzing the impact of an increased bioethanol share in the fuel blend for the Brazilian lightweight fleet transportation sector

Brazil has a successful record of using sugarcane bioethanol as fuel for the lightweight fleet transportation sector through the so-called flex-fuel internal combustion engines (ICE), which equip over 80 % of Brazil's current fleet. Therefore, and motivated by environmental concerns, i.e., the reduced emissions associated with the use of bioethanol in comparison with gasoline in ICE, this study aims to answer the following question: is it possible to fully power Brazil's lightweight fleet with bioethanol instead of gasoline? To answer this research question, detailed homemade technical and environmental models were developed aiming to determine the actual bioethanol demand and the respective emissions under two main premises: (i) constant energy content and (ii) fixed distance driven. In the former, the volume of bioethanol needed is determined through the low heating value of the blend, while the latter used the fuel economy. The developed models account for the fleet size, bioethanol production per area, gasoline/bioethanol blend fraction and the conversion of sugar into bioethanol. The results indicate that, if the entire lightweight fleet is powered by bioethanol, its demand would increase by over 400 %, and emissions would drop by roughly 70 %. The conversion of sugar can increase bioethanol production by 86.7 %. By increasing the average productivity to about 100 tonsugarcane/ha, as already reported, an E100-powered fleet would require doubling the current sugarcane farmed area, which represents an increase from 12.5 % to 37.9 % of Brazil's farmable area. Considering sugar conversion, the area increase is only 10.8 %.