催化热解生物质制取富氢气体的研究

Aimed at producing hydrogen-rich gas, pyrolysis of rice straw and sawdust was carried out in a fixed-bed reactor at different temperatures with catalyst (Cr2O3, MnO, FeO, Al2O3, CaO, CuO and Na2CO3). The results show that at current operating conditions, total gas yield and hydrogen-rich gas yield are low. However, it could be improved by using catalysts. The addition of Cr2O3 at 750 ℃ leads to the increase of the total gas yield by 10% and the concentration of hydrogen-rich gas by 13%. High temperature favours the yield of total gas and the concentration of hydrogen-rich gas. When the temperature rises from 500 ℃ to 850 ℃, the yield of total gas and the concentration of hydrogen-rich gas, for rice straw pyrolysis, increase from 29.0% to 40.6%, and 41.2% to 48.2%, respectively; for sawdust pyrolysis from 35.0% to 46.5%, and 40.6% to 47.0%, respectively. The catalysts used exert positive effect on pyrolysis of rice straw and sawdust, however, Cr2O3 appears stronger catalytic role than other metal oxides. 30% catalysts (CaCO3, Na2CO3) is recommended because higher amount of catalyst almost does not improve catalytic activity again. The addition of CaCO3 or Na2CO3 increases the yields of total gas and also of hydrogen-rich gas. Catalytic performance of Na2CO3 shows a little bit better than that of CaCO3 in the case of rice straw pyrolysis.