Research On SCR Flue Gas Denitration Technology

Nitrogen oxides has always been one of the main sources of air pollution.Having effected the survival of humanity seriously,there is an urgent need to control the nitrogen oxides.The mainstream of current NOx control measures is post-combustion flue gas denitrification technology,among of which,selective catalytic reduction(SCR,Selective Catalytic Reduction)is the most widespread application.Aiming at the increasingly serious problem of atmospheric nitrogen oxide pollution,this paper has systematacially studied SCR DeNOx Technology.Specific work and conclusions are as follows:Firstly,we have designed and built a laboratory simulation platform and industrial flue gas denitrification pilot experiment platform.The former was used for the test of denitration experiments of ecommercial catalyst and powder catalyst we made by ourself,and the latter was used for denitration test of a honeycomb catalyst we made by ourself.Secondly,the commodity crushed catalyst milled in a simulated flue gas denitration catalyst platform for the optimum conditions of the test.The process conditions included flue gas temperature,ammonia ratio,airspeed,the initial concentration of oxygen and nitrogen oxides.The experimental results obtained the optimum conditions:the reaction temperature of 320℃,ammonia ratio of 1.05,a space velocity of 10000h-1,an oxygen content of 4.0%,the initial concentration of nitrogen oxides of 1280 mg/m3.Thirdly,we obtained the SCR DeNOx catalyst powder of different V-W-Ti ratio.In a simulated flue gas denitrification platform,we used the measured product catalyst optimum denitrification process conditions to test the denitrification efficiency to filter the ratio of the three components.And we characterized the catalyst which has the highest ratio of denitrification with SEM and the specific surface area.The optimal ratio of the three components is V：W：Ti = 1:6:100(mass ratio).Finally,based on the best V-W-Ti proportion we have obtained,we added in forming agent A and B to obtain the honeycomb SCR denitration catalysts.Putting forming effect as the standard,we obtained the optimum ratio of A and B is Ti:W:V:A：B = 100:6:1:6:1.5(mass ratio).On this basis,we verified the denitration efficiency of honeycomb catalyst we made by ourself in the industrial platform.As a result,on conditions of the reaction temperature of 350 ℃ ammonia ratio of 1.05,a space velocity of 9000h-1,the oxygen content of 4%,the initial concentration of 900 mg/m3,the denitrification rate reached 88%,which basically met industrial requirements.