介质阻挡放电结合二氧化锰对空气中苯的降解

Degradation of benzene in air stream by dielectric barrier discharge combined with manganese dioxide

为了提高介质阻挡放电技术对空气中苯的降解效率、降低尾气中的残余的臭氧含量,采用水热法制备了二氧化锰催化剂,并结合等离子体对模拟空气中的苯进行了降解研究.通过气相色谱仪测定尾气中苯、二氧化碳和一氧化碳的含量,利用碘量滴定法测定尾气中臭氧的含量,分析了不同功率和不同气体流速对苯降解效率的影响.结果表明,催化剂与等离子体的结合能有效提高模拟空气中苯的降解率和二氧化碳选择比;苯的降解率和二氧化碳选择比随功率的增大而增加,但随气体流速的增大而减小.苯的降解率上升至70.9%,二氧化碳选择比提高至73.8%,同时尾气中臭氧降低为36 mg/kg.

To improve the dielectric barrier discharge technology on the degradation of benzene and reduce the residual ozone concentration in the tail gas, manganese dioxide catalyst was prepared by hydrothermal method, and used to degrade the benzene in the simulated air combined with plasma. The concentrations of residue benzene, carbon dioxide, carbon monoxide and ozone were analyzed by gas chromatography and iodometry. Meanwhile, the degradation efficiency of benzene was evaluated under different power and gas flow rates. The results indicate that the degradation ratio of benzene and the selectivity of carbon dioxide are improved when the plasma degradation and manganese dioxide catalytic degradation are simultaneously used; the degradation efficiency of benzene and the selectivity of carbon dioxide are both improved with the increasing of power, but decrease with the increasing of gas velocity. The degradation ratio of benzene increases to 70.9 % and the selectivity of carbon dioxide grows up to 73.8 %, meanwhile the concentration of ozone reduces to 36 mg/kg with the assist effect of manganese dioxide catalyst.