Sustainability and life cycle analyzes of different biofuel from municipal solid waste processes: an effective environmental guidance

Abstract

Abstract The refining of biowaste into biofuels, particularly focusing on the organic fraction-municipal solid waste (OF-MSW), remains nascent and is influenced by factors such as energy requirements, microbial effectiveness, and structural design. This article presents a sustainable and thorough framework for evaluating the environmental behavior associated with diverse biofuel from OF-MSW conversion methodologies. The evaluation considers three different pre-treatment methods (acetone organosolv, hot water, and acidic pre-treatment), several fermentation techniques (including ethanol fermentation and ABE-F (acetone/butanol/ethanol fermentation)), and acidic or enzymatic hydrolysis approaches. Furthermore, the environmental analysis utilizes the life cycle analysis (LCA) approach. Within this framework, a consequential LCA is implemented, which includes process development to address the issue of multi-functionality and the use of marginal processes for designing foundational processes. The biofuels produced, ethanol and butanol, are analyzed for their environmental impact. To discern the varying and combined effects, methodologies for sensitivity analysis and single score evaluations have been established. Research outcomes suggest that the acetone–ethanol–butanol fermentation scenario does not provide an optimal environmental outcome due to its inability to offset the environmental impacts through the benefits derived from the byproducts. Among the scenarios examined, Scenario SC-IV emerged as the most environmentally beneficial, showing significant net environmental savings including decrements of −854.55 PDF m−2 (potentially disappeared fraction, annually), −253.74 kg CO2.eq per 1000 kg of OF-MSW, and − 3290 MJ per 1000 kg of OF-MSW treated.