title: A study on the consecutive preparation of d-xylose and pure superfine silica from rice husk.
abstract: Rice husk is an abundant agricultural byproduct. In the present paper, research on consecutive preparation of d-xylose and superfine silica from rice husk is carried out. The optimum hydrolysis conditions of xylan in rice husk to d-xylose are as follows: the concentration of H(2)SO(4) is 4% (wt.%), the temperature is 130 degrees C, the ratio of rice husk mass (g) to H(2)SO(4) solution volume (ml) is 1:4 and the time is 2 h. The hydrolysis degree of xylan reaches 96.22% (wt.%). High purity (98.5%, wt.%) d-xylose is obtained from acid hydrolysis solution with the purification yield of 71.63% (wt.%). At the same time, the metal oxides in rice husk are efficiently dissolved by H(2)SO(4). Residuals from H(2)SO(4) pre-treatment are incinerated under 750 degrees C in stationary air for 15 min. Silica is obtained with the purity of 99.87% (wt.%). The superfine silica powder is obtained after ground and ultrasonic dispersion, with the diameter of 30-200 nm and specific surface 287.86 m(2)/g.
authors.affiliation: College of Chemistry, Jilin University, No. 2699, Qianjin Street, Changchun 130012, PR China.
authors.forename: Hongxi
authors.initials: H
authors.lastname: Zhang
authors.forename: Xu
authors.initials: X
authors.lastname: Zhao
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Ding
authors.forename: Hong
authors.initials: H
authors.lastname: Lei
authors.forename: Xue
authors.initials: X
authors.lastname: Chen
authors.forename: Dongmin
authors.initials: D
authors.lastname: An
authors.forename: Yunling
authors.initials: Y
authors.lastname: Li
authors.forename: Zichen
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D006868:Hydrolysis; D008670:Metals / Q000737:chemistry; D012275:Oryza / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D016062:Porosity; D011208:Powders; D012822:Silicon Dioxide / Q000138:chemical synthesis*; D013464:Sulfuric Acids / Q000737:chemistry; D013696:Temperature; D013997:Time Factors; D014994:Xylose / Q000138:chemical synthesis*
chemical_list: D008670:Metals; D010087:Oxides; D011208:Powders; D013464:Sulfuric Acids; D012822:Silicon Dioxide; D014994:Xylose; C033158:sulfuric acid