基于铁基载氧体煤焦化学链气化性能研究

Chemical looping gasification of coal char using iron-based oxygen carrier

用溶胶-凝胶法制备铁基载氧体,以500℃热解得到的半焦为固体原料,利用固定床反应器对制备的铁基载氧体煤焦化学链气化性能进行研究。实验结果表明:当氧碳比为1∶1,水蒸气流量为0.03 mL/min,气化温度为900℃时,煤焦化学链气化反应获得较高的碳转化率和合成气选择性,分别为93.42%和85.48%;水蒸气及载氧体的增多,可以提高煤焦的碳转化率,但同时会消耗合成气,导致合成气选择性降低;气化温度的提高能够促进煤焦气化反应的进行,提高CO和H_(2)的产率,但高温下载氧体易出现烧结问题。此外,煤焦、载氧体与水蒸气三者间的相互作用会随着煤焦气化反应的进行而有所变化。

The performance of coal char chemical-looping gasification was evaluated by fixed bed experiment,during which Fe_(2)O_(3) oxygen carrier was prepared by sol-gel method,and char was obtained by pyrolysis of coal at 500℃.The experimental results show that the coal char chemical-looping gasification reaction obtains higher carbon conversion and synthesis gas selectivity,respectively 93.42%and 85.48%under the conditions of oxygen to carbon ratio 1∶1,steam flow rate 0.03 mL/min,and 900℃.The increase in steam and oxygen carrier content could promote the carbon conversion rate of coal char.However,it consumed synthesis gas at the same time,resulting in the reduction of synthesis gas selectivity.Improving the gasification temperature could promote the degree of coal char gasification reaction,in which increased CO and H_(2) yield.However,the high temperature might cause the sintering problem of the oxygen carrier.Furthermore,the interaction between coal char,oxygen carrier and steam changed with the progress of gasification reaction.