PROPERTIES OF GAS AND CHAR FROM MICROWAVE PYROLYSIS OF PINE SAWDUST
In this paper, pyrolysis of pine sawdust was carried out respectively using microwave and conventional electrical heating at different temperatures in order to understand the properties of pyrolytic products from microwave pyrolysis of biomass. Because the pyrolytic chars can absorb microwave radiation dramatically, the local temperature of biomass particles was higher than the surroundings, which facilitated the biomass pyrolysis process. Therefore, compared to conventional heating method, fewer chars were obtained by microwave pyrolysis at the same temperature. While comparing the components of the pyrolytic gases, analyzed by a gas chromatograph, it was revealed that the microwave pyrolysis gas usually had higher H2, CO contents and lower CH4, CO2 content than those obtained by conventional pyrolysis at the same temperature. The textural properties of the microwave pyrolysis chars were determined by SEM and BET methods, the results showed that the chars would melt and the pores would shrink at high temperatures, and hence, the specific surface areas of the chars decreased with increasing temperature. Which similarly caused that the reactivity of the char, determined by char-CO2 gasification rate on a thermal balance at 1000℃, was remarkably reduced when the microwave pyrolysis temperature exceeded 600℃. Furthermore, the chars produced from microwave pyrolysis were likely to have lower reactivity than that for conventional pyrolysis. In addition, the GC/MS analysis result of the pyrolytic tar from microwave pyrolysis of pine sawdust indicated that the quality of the liquid product from biomass pyrolysis could be improved via microwave heating.
Microwave pyrolysis Pine sawdust Char
Xian-hua WANG Han-ping CHEN Hai-ping YANG Shi-hong ZHANG
State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China
国际会议
广州
英文
1173-1181
2008-12-03（万方平台首次上网日期，不代表论文的发表时间）