Life cycle assessment of bioethanol production from banana, potato, and papaya waste

PurposeFood waste is considered a potential source for biofuel production, with gaps in the processes that need to be addressed and a necessity to evaluate the environmental, economic, and social impacts of these processes comprehensively to assess their sustainability fully. The aim was to conduct a life cycle assessment (LCA) of bioethanol derived from banana, potato, and papaya waste across three process stages (pretreatment, enzymatic hydrolysis, and fermentation).MethodsThe process was assessed in two additional stages: one considering energy consumption and the other excluding energy consumption of the equipment used, referred to as non-energy processes. This distinction was made because a laboratory-scale process was utilized, which does not accurately reflect energy costs on a large scale. The study employed Ecoinvent database 3.4 and the ReCiPe 2016 method (midpoint and endpoint) to evaluate impacts, along with Monte Carlo simulation in SimaPro 8.5.0.0 software for uncertainty analysis.ResultsThe LCA revealed that the fermentation stage accounted for the most significant number of impacts and environmental damages in all categories in the complete processes. In the non-energy processes, the pretreatment stage for waste from evaluated foods exhibited the highest impacts and damages. The most significant environmental impacts and damages across all scenarios were global warming potential (GWP) and resources, respectively.ConclusionsBanana waste has higher impact than potatoes and papaya. Optimizing processes, using renewable energy, sustainable pH adjustment, and enzyme reuse can enhance sustainability. No studies were found that conducted an LCA of bioethanol production from papaya waste.