Process integration and economics of gamma-valerolactone using a cellulose-derived ethyl levulinate intermediate and ethanol solvent

Abstract This study combines two catalytic conversion strategies, cellulose to ethyl levulinate and subsequently to gamma-valerolactone, into an integrated process. The effect of integrating the cellulose-to-ethyl levulinate and ethyl levulinate-to-gamma-valerolactone processes on a commercial scale is investigated to improve energy efficiency and economics by performing a process simulation study. The conversion strategies show a low energy efficiency of 6.8% using excess ethanol solvent to achieve high yields of ethyl levulinate and gamma-valerolactone; however, in the integrated process, 0.4% of the ethanol and 30.8% of the cellulose-to-ethyl levulinate heat requirements are supplied by the ethyl levulinate-to-gamma-valerolactone process. The minimum selling price for the integrated process is estimated to be $5.63/kggamma-valerolactone, which makes it an economically feasible option for gamma-valerolactone production. Finally, we conducted a sensitivity analysis of key parameters (cellulose price, steam price, and ethanol price) highly depending on the minimum selling price of gamma-valerolactone.