Integrated approach for extraction of xylose, cellulose, lignin and silica from rice straw

In this paper, a novel process for xylose production was developed and discovered with simultaneous extraction of other product like cellulose, silica, and lignin. The study explored the effect of chemicals on xylose yield, and the xylose production process was optimized as followings: After pre-impregnation with nitric acid at 140 °C for 15 min, rice straw was treated at 1 bar with 0.5% (v/v) nitric acid, followed by second hydrolysis by using 2.5%(w/v) sodium hydroxide with 2%(w/v) sodium hypochlorite at 121 °C for 1 h, decoloration and ionic impurities were removed by ion exchange. Using this process, 13.8 g of crystal xylose was produced from 100 g rice straw, simultaneously 26.01% (w/w) of cellulose, 10.11% (w/w) silica, and 6.21% (w/w) lignin were also extracted from rice straw respectively. All results indicated that this process is a more effective than the traditional method sulphuric acid hydrolysis process for lignocellulose biorefinery.