O2/CO2气氛下煤中汞的释放特性

摘要

Experimental studies on the mercury release characteristics under O2/CO2 atmosphere were carried out in a vertical tube furnace device. The effects of 21%O2/79%N2 and 21%O2/79%CO2 atmospheres,different O2 and CO2 concentrations on the Hg0(g) release were investigated. The experimental results show that the mercury mass balance ratio is 83.75%—114.1%,verifying the accuracy of the experimental results. Hg0(g) concentration under O2/N2atmosphere is higher than that under O2/CO2 atmosphere at 250—400℃. Under O2/CO2 atmosphere,Hg0(g) release amount is slightly higher than that under O2/N2 atmosphere at 400—600℃. With the O2 concentration increasing,the release amount of the Hg0(g) reduces,which indicates that O2 can enhance Hg0(g) oxidation. Hg0(g) concentration changes little when CO2 increases from 0 to 30%. However,Hg0(g) release amount increases with the rise of CO2 from 30% to 50%. This may be because high CO2 concentration inhibits Hg0(g) oxidation.%在立式管式炉实验装置上研究了O2/CO2气氛下煤中汞释放特性，考察了21%O2/79%N2和21%O2/79%CO2两种气氛下Hg0(g)的释放特性、富氧气氛下O2和CO2浓度对Hg0(g)释放特性的影响。结果表明：汞质量平衡率为83.75%～114.1%，验证了实验结果的准确性。在250～400℃之间，O2/N2气氛中 Hg0(g)的释放浓度高于O2/CO2气氛；在400～600℃范围内，O2/CO2气氛中Hg0(g)的释放浓度略高于O2/N2气氛；富氧气氛下O2浓度越高，Hg0(g)的释放浓度越低，O2对Hg0(g)的氧化具有促进作用；富氧气氛下CO2浓度由0升至30%时，其浓度变化对Hg0(g)氧化的影响不大，而由30%升至50%时，Hg0(g)的释放浓度增加，高浓度的CO2可能会抑制Hg0(g)的氧化。