Microwave-mediated noncatalytic synthesis of ethyl levulinate: A green process for fuel additive production

This study developed a new catalyst-free process for producing ethyl levulinate, a biofuel additive. Noncatalytic levulinic acid esterification with ethanol using microwave irradiation (MW) was compared with that using traditional heating (TH) under different reaction conditions. The results demonstrated that the esterification process using MW was more effective than that using TH. A reaction conversion of 90.38% was obtained for the esterification using MW at 473 K and reaction time of 3 hours. Moreover, this study established a model for depicting the kinetics of levulinic acid esterification using MW and TH. A good fit to the data (R-2 of >.9999) was achieved, indicating the validity of the developed model. The rate constants and pre-exponential factor obtained for the esterification using MW were greater than those obtained using TH. Consequently, the microwave-assisted noncatalytic synthesis is a green and promising method for preparing ethyl levulinate.