生物质半焦与煤混合气化协同作用的动力学研究

在热重分析仪上进行了稻秆半焦和神府煤与CO₂非等温混合气化实验,升温速率20℃/min,终温1200℃。实验结果表明,两种燃料在热解阶段符合加权计算规律,但是在超过800℃的高温气化阶段具有显著的协同作用。与不考虑协同作用的计算结果相比,添加稻秆半焦的煤焦气化反应速率提高,气化反应结束温度降低26℃,最大失重速率提高22%。协同作用的主要原因是稻秆半焦中碱金属具有催化作用,通过动力学分析表明混合气化活化能比煤焦单独气化要低。

Investigation into synergy in co-gasification of coal and char of biomass by thermogravimetric analysis

It is a feasible way for large-scale use of biomass by co-gasification of its char with coal. And the alkali metal salts contained in the biomass can act as the catalyst during gasification. Several co-gasification experiments between coal and straw char were carried out by thermal gravimetric analysis in non-isothermal mode under CO₂ atmosphere at the heating rate 20℃/min and the final temperature 1 200℃. The results show that there is no synergy between the two fuels during the pyrolysis stage, however, an obvious synergy effect is found in gasification stage when the temperature is greater than 800℃. Compared with the results calculated without considering the synergy, the coal gasification reaction is promoted when some straw chars are added. As a result, the final gasification temperature is lowered by 26℃ and the maximum weight loss rate is increased by 22%. The synergy is mainly due to the catalysis of the alkali metal in rice straw. The kinetic analysis shows that the gasification activation energy of the blend fuel is lower than that of coal alone.