Economic Aspects and Sustainability of Ethanol Production - A Systematic Literature Review

Meeting the increasing global energy demand in a sustainable way is a major challenge for humanity. One of the solutions in the transportation sector is ethanol, which is currently the only economically viable direct fuel substitute. In addition to the first-generation technology, which provides the vast majority of production, better results can be continuously realized by using advanced technologies. This study aims to investigate the economic aspects and sustainability issues of ethanol production with a systematic literature review. During the selection process, 64 studies from a total of 16,141 identified articles were analyzed in-depth. There is a consensus that first-generation production methods cannot result in a long-term solution. However, advanced technologies are currently immature, and ethanol production is more expensive with them. The use of wastes/residues and coproducts can improve both the economic outlook and sustainability of the advanced technologies. Overall, the newer generations of technological advancements are constantly improving the environmental performance, whereas the economic performance is deteriorating. Considering low oil prices (0.36 USD/L), none of the ethanol production methods can be competitive on a purely cost basis. This increases the importance of coproducts (further processing and more valuable coproducts). Regarding sustainability, a complex analysis is essential, which must cover at least the environmental, social, and economic aspects. At the methodology level, a complex life cycle analysis seems to be the best tool, as it can take into account these relevant aspects (environmental, economic, and social)