Experiment investigation of Rice husks Carbonization with Slow Heat rating
Rice husk is an important agricultural by-products in China. A great number of rice husk requires disposal with the development of the rice agricultural and thus poses an environmental problem. To produce activated carbons is important and economical method to disposal rice husk. This paper investigated the characteristics of the rice husk chars carbonized with a slow heat rating. The carbonization temperatures were from 350℃ to 850℃ and the heat rating was 6℃/min. And the analysis of nitrogen isotherms at respective boiling points was made to investigate the evaluation of the pore size distribution function of the chars at different carbonated temperature. Results showed that the higher the carbonated temperature the smaller the resulting solid yield and the larger the specific surface area of the chars. No micropore and mesopore is found in the char obtained at 350℃. The mesopore is begin found after 450℃ and the micropore will be obtained after 550℃. the surface area was above 200 m2/g for the chars obtained above 550℃, then low cost adsorbent would be prepared by simple carbonization process from the rice husks The ash of the char is 30％-50％ weight of the char. Removing the ash form the char may improve the characteristic of the char. Three chars in different carbonized temperature were impregnated in the NaOH solution (1.5mol/L) at 100℃ and the impregnation time was 3 hour. Results showed this treat can remove about 92 wt％ ash content and the low heat value and the specific surface area increased significantly. There may be a special inlay structure between the ash content and the carbon texture. Fractal analysis shown that the surface roughness of the chars obtained higher temperature is higher and alkali separation would change the surface roughness.
rice husk char carbonization the surface area alkali separation fractal analysis
Ying-quan Chen Han-ping Chen Hai-ping Yang Xian-hua Wang Shi-hong Zhang
State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan,430074,E R. China
国际会议
广州
英文
1336-1341
2008-12-03（万方平台首次上网日期，不代表论文的发表时间）