Production of Bioethanol from Pretreated Rape Straw: Focus on Low Energy Input in Distillation Process

Abstract

For ethanol production, distillation is a necessary process, but it is a high energy-consuming process. In the distillation process, a low initial ethanol concentration requires a high energy input. In this work, pretreated rape straw was used to produce bioethanol after enzymatic hydrolysis. In order to improve the initial concentration of bioethanol, a high solids content was used both in enzymatic hydrolysis and the fermentation process. The results showed that the glucose and bioethanol concentration reached 76.2 and 46.0 g/L, respectively, after enzymatic hydrolysis and fermentation when the solids content was fixed at 25 % (w/w). Compared to the solids content at 10 % (w/w), the glucose and bioethanol concentration increased 124 and 105 %, respectively. In addition, the time series analysis method was used to estimate the bioethanol yield of a city in southwest China.