Comparative techno-economic assessment of sugarcane biorefineries producing glutamic acid, levulinic acid and xylitol from sugarcane

Abstract

In this study, six alternative biorefinery scenarios for the production of levulinic acid (LA), glutamic acid (GA) and/or xylitol- or a combination of these chemicals- annexed to an existing sugar mill in 1G-only (molasses feedstock) or integrated 1G2G (molasses and sugar cane lignocellulose feedstock) configurations were simulated in AspenPlus®. Then, mass and energy balances obtained from the simulations were used for the subsequent equipment sizing and costing and to perform the economic performance assessments of the scenarios. All the investigated scenarios were identified as profitable scenarios with the internal rates of return (IRRs) ranging from 21.3%−59.8%. Generally, GA scenarios showed better economic outcomes compared to LA counterparts, attributed to the factors such as higher market prices, higher product throughput and less complicated processing technology which lowers the cost of production. Considering the market size and economic outcome, the 1G GA scenario producing 11.1 t/h GA showed the best economic performance with 59.8% IRR and a minimum product selling price (MSP) of $1687/t. However, a multiproduct facility (1G2G GA-xylitol) can result in more robust economic performance, as a result of implementing xylitol mature technology. Although all investigated scenarios showed profitability potential, life cycle analysis (LCA), social impact assessment and market analysis are required to find out the most sustainable biorefinery option.