某垃圾焚烧发电机组脱硝催化剂失活原因分析OA

For the honeycomb denitrification catalyst used in a waste incineration generating unit,it was periodically tested at a cycle of 4000 h. The catalysts were characterised by a physical absorption and desorption analyser and an X-ray fluorescence spectrometer. The chemical composition,physical properties and catalytic performance of the new catalyst and deactivated catalyst were analysed,characterised and evaluated using a physical adsorption and desorption analyser,an X-ray fluorescence spectrometry analyser,and a full-size performance evaluation device for denitrification catalysts,respectively. The results showed that after 4000 h of catalyst operation,the contents of sodium,potassium and calcium on the surface increased,and the contents of vanadium and tungsten oxides decreased,which was caused by the enrichment of sodium,potassium and calcium oxides on the catalyst surface covering part of vanadium and tungsten;after 16000 h of catalyst operation,the specific surface area and pore volume on the catalyst surface decreased by 43.06％ and 33.33％,respectively,and the average pore diameter increased by After 16000 h of operation,the specific surface area and pore volume of the catalyst surface decreased by 43.06％ and 33.33％,respectively,and the average pore size increased by 80.99％,due to the enrichment of alkali and alkaline earth metal elements in the flue gas on the surface of the catalyst,which resulted in the loss of the microporous structure of part of the catalyst and the decrease in the number of active sites,thus affecting the performance of the catalyst. After testing,the activity of the first and second layer catalysts decreased to 41.4％ and 57.1％ of the initial activity respectively,and the second layer catalyst was less affected. The two catalyst layers in series can meet the requirement of 65％ denitrification rate of the unit,and the ammonia escape concentration is 3.87 mg/m3,which exceeds the requirement of relevant national standards.