Dual liquid–liquid extraction versus distillation for the production of bio-butanol from corn, sugarcane, and lignocellulose biomass: A techno-economic analysis using pinch technology

Abstract

n-Butanol has emerged as a potential biofuel and promising feedstock for organic chemicals. This study presents a techno-economic comparison of dual liquid–liquid extraction (LLE) with distillation for manufacturing 10,000 MT bio-butanol per annum from corn, sugarcane, and lignocellulose biomass using pinch technology. The energy consumption per kg of bio-butanol was lower in dual LLE than distillation. However, the dual LLE involves the complex recovery of extractants with high capital investment and utility consumption. The bio-butanol production cost was thus slightly higher for dual LLE than distillation. Despite the high capital investment, the bio-butanol production cost was much lower for lignocellulose biomass than corn and sugarcane due to cheaper feedstock and higher co-product credit. The production cost was, however, higher for corn compared to sugarcane due to higher feedstock cost, additional enzymatic hydrolysis step, and extra cost for enzymes and nutrients. The production cost per kg of bio-butanol from corn, sugarcane, and lignocellulose biomass was USD 1.50, USD 1.11, and USD 0.65 for distillation and USD 1.59, USD 1.19, and USD 0.74 for dual LLE, respectively. The feedstock contributed 53–70% of the production cost with ∼130%, ∼60%, and ∼40% contribution of co-product credit for lignocellulose biomass, sugarcane, and corn, respectively. The profitability analysis was further carried out to obtain the minimum bio-butanol selling price.