Integrated production of furfural and levulinic acid from corncob in a one-pot batch reaction incorporating distillation using step temperature profiling

Furfural and levulinic acid (LA) are potential major renewable platform chemicals for producing biochemicals and biofuels. In this study, integrated conversion of corncob to furfural and LA was carried out in a one-pot system using p-toluenesulfonic acid (p-TsOH) and step temperature profiling. A batch reaction incorporating distillation (BRD) resulted in a good furfural production yield of 61.6% based on the corncob xylan content for the hydrolysis conditions tested. Distillation not only reduced furfural loss due to side reactions to humins, but also resulted in a fairly pure and concentrated furfural solution. At the end of the first distillation step, the reaction temperature was increased to convert hexoses into LA with a maximal production yield of 61.3 ± 7.8% based on corncob glucan content. LA was extracted with good yield as LA–ester using low-cost alcohols and then phase separated to recycle alcohols and p-TsOH. Good recyclability and reusability of p-TsOH and alcohols were demonstrated.