Experimental Analysis On Desulfurization And Denitrification Of Coke Oven Flue Gas

The new national coking industry emission standard,"Coking Chemical Industry Pollutant Discharge Standard"?GB 16171-2012?,specifies the emission limits for the first time for emission of atmospheric pollutants NO_x from the furnace stack,and SO₂ emission limits are also more stringent.Under the background of this research,this study carried out experiments on the desulfurization and denitration of coke oven flue gas.This article is based on the summary of domestic and foreign industrial typical desulfurization and denitrification process,based on the analysis of coking plant coke oven flue gas exhaust working conditions characteristics,proposed three kinds of coke oven flue gas desulfurization program,respectively:dry method Desulfurization,semi-dry two-fluid spray desulfurization,and semi-dry rotary atomization desulfurization;two kinds of coke oven flue exhaust gas denitrification schemes:CATCERA nano-ceramic bag-shaped cryogenic SCR denitration,V2O5-WO3/Ti O2 honeycomb cryogenic SCR method denitrification.The sodium base was first selected as the desulfurizer for the entire experimental study.The dry desulfurization test was conducted using NaHCO₃ desulphurizer,and the semi-dry desulphurization test was performed on Na2CO3 desulphurizer.The sodium-sulfur ratio,the temperature difference between the outlet and the adiabatic saturation temperature,the inlet flue gas temperature,and the flue gas in the absorption tower were mainly studied.The influence of operating parameters such as flow rate,particle size of desulfurizing agent droplets on desulfurization efficiency.Then the two kinds of SCR denitration methods were respectively tested for the exhaust gas denitration of the coke oven flue.The two methods used the high-purity20%-concentration ammonia water as the reducing agent for the denitrification reaction.The two types of denitration catalysts corresponding tests were the CATCERA nanometers.Ceramic bag-like cryogenic SCR denitration catalyst and V₂O₅-WO₃/TiO₂ honeycomb cryogenic SCR denitration catalyst.The effects of reaction parameters such as reaction temperature,space velocity,ammonia-nitrogen ratio,catalyst form,and NH₃ slip on the denitrification efficiency were studied.According to the analysis of the above tests,the two schemes of“half-dry Na₂CO₃ rotary spray desulphurization”and“V₂O₅-WO₃/TiO₂ honeycomb low-temperature SCR denitrification”are combined in special areas required by the new emission standards.The above-mentioned several types of desulfurization and denitrification scheme are the best solutions.For the general areas required in the new emission standards,the two schemes of“dry NaHCO₃ desulfurization”and“V₂O₅-WO₃/TiO₂ honeycomb cryogenic SCR method denitrification”are combined as the best solution in the above-mentioned several desulfurization and denitration schemes.