碳酸钾和高铁酸钾催化热解中药渣固废的对比实验

Comparative experiments on the catalytic pyrolysis of herb residue by K2CO3 and K2FeO4

以中药渣为原料,通过浸渍法分别负载高铁酸钾(PF)和碳酸钾(PC)催化剂,利用热重分析仪、在线质谱和固定床反应器研究了PC和PF对中药渣催化热解过程的影响机制。结果表明,PC和PF均降低了中药渣的热解反应温度,强化了水蒸气重整反应,显著提升了热解气产率和H2含量。PC将药渣热解活化能由206.9 kJ/mol降至149.3 kJ/mol,PF的自身热分解反应,则小幅增加热解活化能至218.7 kJ/mol。300℃时,PC和PF有效促进了中药渣的低温热解反应,气体收率分别增加了83.3%和69.3%;500℃时,催化剂促进了H2的生成,将热解气的H2/CO比由0分别提升至1.29和1.92;700℃时,PC、PF能大幅降低液相收率,提高气体产物的H2/CO,PF效果更为明显,液相收率降低了30.9%,H2/CO提高了38.5%。但PF在热解过程中会分解释放氧气,使得NO排放量增加。

The effects of K2CO_(3)(PC)and K2FeO4(PF)on the catalytic pyrolysis of herb residue were investigated by using a thermogravimetric analyser,online mass spectrometry and a fixed-bed reactor,using herb residue as the raw material and loaded with PF and PC catalysts respectively by impregnation.The results showed that both PC and PF lowered the pyrolysis reaction temperature of the herb,enhanced the water vapour reforming reaction and significantly increased the pyrolysis gas yield and H2 content.At 500℃,the catalyst promoted the production of H2 and increased the H2/CO ratio of the pyrolysis gas from 0 to 1.29 and 1.92,respectively;at 700℃,PC and PF can significantly reduce the liquid-phase yield and increase the H2/CO of the gas product,with PF being more effective,reducing the liquid-phase yield by 30.9%and increasing the H2/CO increased by 38.5%.However,PF will decompose and release oxygen during the pyrolysis process,which makes NO emissions increase.