Environmental Sustainability Assessment of Molasses-based Bioethanol Fuel in Pakistan

Abstract

Bioethanol is promoted as a transportation fuel due to its perceived benefits; reducing greenhouse gas (GHG) emissions, substituting fossil fuels, enhancing energy security, and promoting the rural economy. This study aims to evaluate the availability potential, energy performance, and environmental sustainability of bioethanol from sugarcane molasses in Pakistan. It was found that the current potential of molasses-based bioethanol is enough to replace around 7% of total gasoline consumption in the country. The results indicated that the use of E10 (10% blend of bioethanol with gasoline) instead of gasoline would result in the reduction of GHG emissions by 8%, human carcinogenic toxicity by 3%, and fossil resource scarcity impacts by 9%. However, E10 has comparatively higher impacts than gasoline on acidification by 20% and on freshwater eutrophication by 43%. Further benefits of molasses-based bioethanol were evident in terms of high energy gains where each MJ of the total energy input provided about 2 MJ of energy output from bioethanol and each MJ of fossil-based energy input resulted in the production of around 6 MJ of energy output from bioethanol. Furthermore, considerable improvements in performance were indicated by contemplating different existing practices and plant arrangements.