Life cycle assessment and techno-economic analysis of fuel ethanol production via bio-oil fermentation based on a centralized-distribution model

Abstract

Fuel ethanol from biomass resources has been gaining attention. Fuel ethanol production via a regional bio-oil production and a central bio-oil direct or indirect fermentation appears interesting and innovative. Techno-economic-environmental analysis is used to evaluate the economic feasibility and environmental impacts of this production process at the industrial scale. The rigorous process models for the fuel ethanol production via bio-oil fermentation are developed using R software. The internal rates of return and the minimum selling price are estimated based on techno-economic analysis; global warming potential 100a, cumulative energy demand, and eco-indicator 99 methods are used using three allocation methods based on life cycle assessment. A sensitivity analysis and an uncertain analysis of the techno-economic-environmental indicators are also conducted. For the direct and indirect fermentation pathway, the internal rates of return is separately 25.6% and 41.5%, and the minimum selling price is $218/metric ton ethanol ($0.98/gge) and $264/metric ton ethanol ($1.19/gge), respectively. According to economic value-based allocation methods, the life cycle assessment indicates the global warming potential (GWP100a) of the production of 1 kg of ethanol via the bio-oil direct fermentation pathway and the bio-oil indirect fermentation pathway is 0.729 kg CO2-eq/kg ethanol and 0.718 CO2-eq/kg ethanol, respectively. The calculation and analysis results show that fuel ethanol production by the indirect bio-oil fermentation pathway is more economically feasible and environmentally friendly and could be attractive to capital markets.