Design and techno–economic analysis of levulinic acid production process from biomass by using co-product formic acid as a catalyst with minimal waste generation

Abstract

Levulinic acid (LA) is an essential biomass-derived platform chemical that can be converted into value–added chemicals such as polymers, fertilisers, and pharmaceuticals. However, the high energy demand and cost required in the separation process are significant issues in the LA production process. Recently, formic acid (FA), the co–product in biomass–LA reaction, has been focused on as a catalyst for both biomass pretreatment and LA production. This study designed and numerically simulated a novel process for producing LA from wheat straw (feed rate: 100 kg/h) using an FA aqueous catalyst system (60, 70, and 80 wt%). The reaction data were referred to previous kinetics studies in order to evaluate the feasible reaction time from an economic perspective. The minimised waste generation process was designed by recovering the FA catalyst and using solid residues (lignin and humins) as heat sources. Another byproduct, furfural, was utilised as an extractant for purifying the LA and recovering unreacted products. The minimum selling price (MSP) of the LA and furfural was calculated with an internal rate of return of 6.1% for 20 years. The MSPs were calculated to be 9.59–12.8 USD/kg–products, which was higher than the market price and previous studies. However, the net required energy in this process was − 5.37 to − 32.1 MJ/kg–LA, indicating that the combustion of the solid residue can supply all of the energy required for the process. Our novel concept based on the byproduct utilisation for heat source and extractant can be an effective strategy for an implication of the biorefinery process that can circulate energy with minimum waste generation.