O_2/CO_2气氛下煤中汞的释放特性

Release characteristics of mercury in coal under O_2/CO_2 atmosphere

在立式管式炉实验装置上研究了O_2/CO_2气氛下煤中汞释放特性,考察了21%O_2/79%N_2和21%O_2/79%CO_2两种气氛下Hg^0(g)的释放特性、富氧气氛下O_2和CO_2浓度对Hg^0(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,O_2/N_2气氛中Hg^0(g)的释放浓度高于O_2/CO_2气氛;在400~600℃范围内,O_2/CO_2气氛中Hg^0(g)的释放浓度略高于O_2/N_2气氛;富氧气氛下O_2浓度越高,Hg^0(g)的释放浓度越低,O_2对Hg^0(g)的氧化具有促进作用;富氧气氛下CO_2浓度由0升至30%时,其浓度变化对Hg^0(g)氧化的影响不大,而由30%升至50%时,Hg^0(g)的释放浓度增加,高浓度的CO_2可能会抑制Hg^0(g)的氧化。

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%CO2atmospheres,different O2 and CO2 concentrations on the Hg^0（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. Hg^0（g） concentration under O2/N2 atmosphere is higher than that under O2/CO2 atmosphere at 250—400℃. Under O2/CO2 atmosphere,Hg^0（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 Hg^0（g） reduces,which indicates that O2 can enhance Hg^0（g） oxidation. Hg^0（g） concentration changes little when CO2 increases from 0 to 30%. However,Hg^0（g） release amount increases with the rise of CO2 from 30% to 50%. This may be because high CO2 concentration inhibits Hg^0（g） oxidation.