Abstract
Bioethanol production from woody biomass by enzymatic hydrolysis of cellulosic components and fermentation has attracted much attention. In this process, pretreatment is important to improve enzymatic degradability of cellulose. A milling process is one of the most effective methods for pretreatment, but its high cost has been a problem. Recently we have developed the economically-feasible wet-mechanochemical process as milling pretreatment, which can unravel cellulosic components into nanoscale fibers. Thus-obtained nanofibrous product showed a high enzymatic accessibility, while keeping the cellulose crystalline structure and the lignin content. This process is based on the understanding of the nanoscopic structural characteristics of wood and cellulose.