Consecutive Synthesis of Xylose,Porous Carbon and Silica by High-efficient Utilization of Rice Husk

Batch hydrolysis of hemicellulose in rice husk was conducted under various operating conditions,and orthogonal test design was adopted to achieve the highest xylose yield. The optimum hydrolysis temperature,sulfuric acid concentration( mass fraction),and hydrolysis time were determined to be 130 ℃,2% and6 h,respectively. Hydrolysis rate of 96. 81% was attained under the optimum conditions( the content of hemicellulose in rice husk was used as benchmark). Xylose yield of 62. 8% was reached after the impurities were removed from the xylose solution. Porous carbon with well-developed uniform pore structure was prepared by the residue of hydrolyzed rice husk. It had high adsorption capability for pigment in xylose solution,but low adsorption capability of xylose,making it a good adsorbent to purify xylose. Silica of high purity was also obtained during the preparation of porous carbon.