Strategies to reduce the negative impact of inhibitors in biorefineries: A combined techno-economic and life cycle assessment

Abstract

Production of 2G ethanol in biorefineries can contribute to a low-carbon bioeconomy, but bioreactor low yields remain a limitation. In this work, technical-economic-environmental biorefinery assessment was performed, with integration of biomass washing and soybean protein addition to mitigate the negative effects of inhibitors on biochemical reactions. It was possible to reduce the overall CO2 emissions of integrated first (1G) and second generation (2G) sugarcane biorefineries, with up to 15% lower global warming potential (GWP10), enabling high commercialization of decarbonization credits (CBios) and significantly increasing net present value (NPV). The most profitable scenario was using biomass washing (NPV ∼ US$ 1.50E+8), but most life cycle categories (except GWP100 and photochemical oxidation) presented greater environmental impacts (2–18%) than conventional 1G2G. The lowest life cycle scores were obtained with protein addition, while the combined mitigation strategies resulted in economic feasibility (due to high CBios prices and low soybean protein costs).Therefore, decisions to favor the bioeconomy should not be based exclusively on the carbon footprint indicator.