改性蒙脱石负载V2O5脱除气态Hg0的性能研究OACSTPCD

In order to solve the pollution problem of mercury emission from coal-fired flue gas,V2O5/MMT catalyst was prepared by loading V2O5 onto montmorillonite(MMT)modified by H2SO4 and used to remove mercury from coal-fired flue gas.The V2O5/MMT catalyst,which combined the catalytic oxidation activity of V2O5 and the adsorption performance of modified MMT,was expected to remove mercury cost-effectively.Its Hg0 removal capability in simulated flue gas and regeneration performance after Hg0 removal were studied.Meanwhile,the effects of H2SO4 modification,preparation condition,V2O5 loading amount,reaction temperature,flue gas components(O2,SO2,NO,H2O(g))and regeneration condition on Hg0 removal by V2O5/MMT were investigated.The V2O5/MMT catalysts before and after Hg0 removal were charac-terized by XRD,BET,SEM-EDS,XPS and TPD.The results indicate that V2O5/MMT cata-lyst has a good Hg0 removal capability,which is mainly due to the co-effect between catalytic oxi-dation activity of V2O5 and adsorption ability of modified MMT.Hg0 removal efficiency by 3％V2O5/MMT catalyst(3％V2O5 loading)is over 98％at 150℃ with a space velocity of 6000 h-1.O2 and NO have promoting effects on Hg0 removal by V2O5/MMT catalyst,SO2 has a slight promotion effect,while H2O has an inhibitory effect.The results of XRD and BET show that the specific surface area of MMT increases by H2SO4 modification,but the interlayer spacing decreases.SEM-EDS results indicate that the V2O5/MMT catalyst has a good pore structure,and the active component V2O5 distributes well on the surface of MMT support.The results of XPS and TPD confirme that Hg0 is oxidized to form HgO and HgSO4 on V2O5/MMT catalyst,which are then adsorbed on V2O5/MMT catalyst.V2O5/MMT catalyst has good regeneration performance after Hg0 removal.