A one-pot method for the enhanced production of xylitol directly from hemicellulose (corncob xylan)

Abstract

An efficient one-pot reaction system for converting hemicellulose (corncob xylan) into xylitol was developed by using a heterogeneous catalyst and water as solvent, without the presence of any acids. A xylitol yield of 46.3% was achieved after 45 min of reaction using Ru/CNT as catalyst, which showed excellent stability after repeated use. Since the conversion of hemicellulose consists of xylan hydrolysis to xylose followed by the subsequent hydrogenation to xylitol, the two steps were then evaluated separately. The effect of the presence of cellulose on the conversion of xylan and distribution of products was also studied and the yield of xylitol was increased up to around 60% in less than 1 h of reaction. Furthermore, a yield of sorbitol over 80% could also be attained in just 2 h of reaction. Being this result one of the best ever reported for the direct conversion of cellulose and hemicellulose using an environmentally friendly approach, the proposed method shows great potential for the optimization of the catalytic production of xylitol and sorbitol.