Hot Carbon Denitrification Reduction Technology Research

Nitrogen oxides is one of the major toxic gases in industrial emissions,and it's a great threat to human health and environment.Photochemical smog,acid rain,ozone depletion will appear when nitrogen oxides was let into the atmosphere too much,and then affect the human living environment.The emissions target of nitrogen oxides is getting stricter,and the removal of nitrogen oxides in industrial flue gas has attracted more and more attention,the effective treatment of nitrogen oxides has become the key to environmental protection.The selective catalytic reduction(SCR)flue gas denitrification technology is currently the mainstream denitration technology in our country,and is widely used in coal-fired power plants.With the environmental requirements increasingly strict,steel,cement,metallurgy,glass and other industries will also face serious denitrification problems.However,SCR denitration technology has some disadvantages as catalyst poisoning,the high cost and secondary pollution caused by ammonia leakage.Activated carbon has been successfully applied in the engineering of dry denitrification because of its good adsorption and catalytic performance,and there is no catalyst poisoning problem.Compared with other denitrification processes,activated carbon has a broader range of applications and a good development prospect.Denitrification performance under low temperature and carbon consumption with the presence of oxygen are two key points to hot carbon reduction denitrification technology.So this paper used coconut shell activated carbon as the reducing agent to explor the C-NO reaction.On this basis,activated carbon was modified by load metal elements to improve the low-temperature denitration performance and selectivity of C-NO reaction.The main contents and conclusions show as following:(1)High temperature is beneficial to the C-NO reaction,it means a higher NO reduction rate;NO reduction rate will decrease with the extension of time;The presence of oxygen can improve the low-temperature denitration performance,but lead to more carbon consumption,so the reduction rate of NO will decline in the latter stage.(2)The low-temperature denitration performance will be improved when the activated carbon modified by Co,Cu,Fe,Ni,K and Ca elements.Activated carbon modified by Co element has the best low-temperature denitration performance,and seven percent is the optimal.(3)The second element like Cu,Fe,Ni,K loaded on activated carbon with Co will improve the denitration performance,and K has the most obvious improvement.In addition,Ni and Ca can reduce the conversion of carbon,but Ca will decrease the denitrification activity at the same time.