Study On Heavy Metal Poisoning And Its Regeneration Technology Of DeNO_x Catalyst

Selective Catalytic Reduction(SCR)is the most mature and effective method to remove nitrogen oxides from flue gas.As the core of SCR denitrification system,the performance of catalyst is directly related to the overall denitration efficiency.However,the use of catalyst for a long time will cause the catalyst plugging and catalyst poisoning,etc.,in these effects,heavy metal poisoning is also an important factor can not be ignored.This paper focuses on heavy metal lead and arsenic poisoning and its regeneration technology.The lead poisoning and its regeneration in denitrification catalyst were as follows: the deactivated part was immersed in the fresh catalyst in different concentrations of lead acetate as the precursor solution to simulate the poisoning of the catalyst in the power plant,and through the experimental device of the catalyst evaluation device,Ratio,loading,lead / vanadium molar ratio on denitrification performance.The optimal experimental conditions and the lead / vanadium molar ratio of denitrification were investigated.The results showed that the denitrification performance of the catalyst was better than that of the pure water.The results show that the regeneration of lead-poisoned catalyst is an essential method;the acetic acid has obvious effect in pickling;the selectivities of diethylenetriamine and triethylenetetramine in the selected complexes are obvious,And the relative triethylenetetramine was better.The cleaning method of mixed water,acetic acid and triethylenetetramine was the best,and the denitration efficiency could reach 94.05% of the original fresh catalyst.The arsenic poisoning and regeneration of denitrification catalyst are as follows: Inactivation part,different concentration arsenic standard solution is immersed in the fresh catalyst to simulate the poisoning of the catalyst in the power plant,and the test device of the catalyst evaluation device is built.,Ammonia-nitrogen ratio,loading,arsenic / vanadium molar ratio on denitrification performance.The optimum experimental conditions and the arsenic / vanadium molar ratio of denitrification were studied.The results show that the denitrification rate is higher than that of arsenic / vanadium.The results show that: in the regeneration of arsenic poisoning catalyst,water washing is an indispensable method;pickling acetic acid has a more obvious effect;selected several basic compounds in sodium nitrate and sodium carbonate regeneration effect is obvious,the relative carbonic acid Sodium,sodium acetate and sodium carbonate were the best.The denitrification efficiency was almost 93.13% of that of the original catalyst.