Techno-economic analysis of bioethanol preparation process via deep eutectic solvent pretreatment

This study conducted a techno-economic analysis of the biorefining process via deep eutectic solvent pretreatment. Rice straw was the feedstock to prepare main product bioethanol, and by-product lignin. The economic analysis model with sensitivity analysis based on Aspen Plus was applied to evaluate the commercial potential and the impact of critical parameters on the minimum ethanol selling price (MESP). Acidic DES showed better results in biomass refining. MESP based on choline chloride/urea pretreatment process was 3049.9 $/ton, while the choline chloride/lactic acid pretreatment was 2128.1 $/ton. The bioethanol yield was 0.21 t/t via choline chloride/lactic acid pretreatment process, which was higher than choline chloride/urea. In choline chloride/ lactic acid pretreatment, sensitivity analysis showed that due to the enzymatic hydrolysis of cellulose conversion rate, acetone price, and lactic acid price, MESP was fluctuated by 23.4 %, 6.25 %, and 5.31 %, respectively. Combined heat and power part could reduce MESP. High solid loading pretreatment had a positive impact on cost reduction.

Automated summary

This study analyzed the biorefining process using deep eutectic solvent pretreatment, showing that acidic DES had better results in biomass refining. The choline chloride/lactic acid pretreatment process had higher bioethanol yield and lower MESP. Sensitivity analysis indicated that factors like cellulose conversion rate, acetone price, and lactic acid price significantly affected the MESP fluctuation.