微波放电对脱硫活性焦循环再生的影响

Effect of Microwave Discharge on the Regeneration of Desulfurization Activated Coke

在微波反应器中利用微波诱导脱硫活性焦放电再生,研究微波放电对脱硫活性焦再生产物及循环再生性能的影响。实验结果表明随着平均放电强度的增加,再生释放CO的量增大,SO2的得率减小,质量损失增大;再生后活性焦的孔隙结构被破坏,吸附SO2的活性位增多,含氧官能团减小,碱性增强。再生后1117cm-1处出现含硫S-C-O吸收振动峰,1053cm-1处出现很强的-S=O吸收振动峰,400W强放电再生后比表面积降到原样的20%,SO2的吸附容量降到原样的64%,活性焦表面化学性质对SO2吸附容量的影响更大;放电再生产生等离子体可能会与脱附的SO2分子高速碰撞,使SO2分子由基态变为激发态,促进C-SO2的还原反应。微波放电再生产物是S、CO、CO2和含硫化合物。

For studying the effect of microwave discharge intensity on the regenerated products and performances of activated coke after desulfurization, the regeneration of activated coke induced by microwave discharge in a microwave reactor was carried out. The experimental results show that the release amount of CO during regeneration increases with the increase of average discharge intensity,while the yield of SO2 decreases, and the mass loss increases.The pore structure of the regenerated activated coke is destroyed, the active sites for adsorbing SO2 increases, the amount of the oxygen-containing functional groups reduces,and the alkalinity enhances. The absorption vibration peak of S-C-O at 1117 cm-1 appears in the infrared spectra of the regenerated activated coke, and the absorption vibration peak of -S = O at 1053 cm-1 is found to be stronger. When microwave power is set at 400 W, the specific surface area decreases to the original 20%, and the adsorption capacity of SO2 decreases to the original 64%. The surface chemical properties of activated coke has much more influence on the adsorption capacity of SO2. Microwave discharge during regeneration could generate plasma, colliding with the desorbed SO2 molecule at high speed, and the change of the latter from the ground state to the excited state promotes the reduction reaction of C-SO2. The regenerated products are S,CO, CO2 and sulfur compounds.