Experimental Study On Desulfurization, Denitrification And Mercury Removal By Activated Carbon

The simultaneous removal technology of SO₂,NO and Hg with carbon-based adsorbent has good application prospects.At present,desulfurization,denitration and mercury removal technologies with carbon-based adsorbent include activated coke adsorption,activated carbon particles（GAC）adsorption and adsorbent with metal oxides loaded,and activated carbon fiber removal technology is under research.Activated carbon is a kind of adsorbent,but also the carrier of catalyst and reactants.In order to improve the adsorptive and catalytic activity of activated carbon,it needs to be activated and modified.Activated carbon can be modified to change its surface structure and groups to enhance its adsorption performance.Activated carbon surface structure modification methods can be divided into three kinds:physical,chemical and physical chemistry Cross-linked.Surface modification methods include high temperature treatment,surface oxidation modification,reduction modification,loading of metal or oxide modification and addition of active agents.This article through the literature review and a large number of experiments,with various of modified reagents to improve desulfurization denitrification and mercury removal ability of activated carbon.It’s determined to modify coal activated carbon by urea and potassium hydroxide whose mass concentration both are 15%.The effects of adsorption temperature,concentration of O₂ and concentration of CO₂ on the performance of desulfurization,denitration and mercury removal was investigated by using a self-designed fixed-bed reactor.Activated carbon desulfurization,denitrification and mercury removal experiments found that as the temperature increases,the modified activated carbon desulfurization and denitrification efficiency increased,mercury removal efficiency decreased;The presence of O₂ promotes the desulfurization,denitration and mercury removal of modified activated carbon;NO promotes SO₂ removal,but SO₂ inhibits NO removal;NO and SO₂ promote mercury removal.Modified activated carbon desulfurization and denitrification experiments found that with the increase of O₂ content,the modified activated carbon desulfurization and denitrification efficiency increased;With the increase of CO₂ concentration,the desulfurization efficiency of modified activated carbon first increases,then decreases,while the denitrification efficiency is the opposite;The desulfurization efficiency of modified activated carbon increases with the increase of temperature,and the denitration efficiency of activated carbon decreases with the increase of temperature.According to the characteristics of activated carbon desulfurization and denitrification and mercury removal,based on the experiment,a new technology and device with high decontamination efficiency,simple regeneration process and product reclamation are proposed.