Study On Regeneration Of SCR DeNOx Catalysts

The core of the SCR denitrification system is the denitrification catalyst,and its performance will directly affect the denitrification effect of the SCR system.At present,most of the catalysts in China rely on foreign technology.Their production cost and price are both high,and moreover,the operation cost of the denitrification system will also increase along with the deactivation of catalysts.Therefore,it is of great significance to study the regeneration method of the poisoned catalyst.The main idea of this work is to study the effect of the deionized water,dilute sulfuric acid and the active load on the commercial denitrification catalyst,and optimize the regeneration conditions.In addition,the strength regeneration of the catalyst is carried out by coating method.Then,after the selection of the binder and the optimization of coating process,the damaged catalyst is regenerated by strength.The main conclusions are as follows:(1)The process route obtained in this study is as follows:water washing,ultrasonic pickling(0.5mol/1 sulfuric acid,20min),active loading(V:26g/L,20min,ultrasonic)and roasting(3h,500?).This process can make the denitrification efficiency of the active load catalyst increase up to 90%.The denitrification efficiency of the catalyst wil be improved after ultrasonic cleaning.The ultrasonic assisted cleaning of 20min can clean up the dust in the catalyst hole and increase the denitrification efficiency from 82.1%to 89.5%.(2)By comparison with the specific surface area of catalyst samples,both acid pickling and vanadium load can increase the specific surface area of catalysts.The specific surface area can increase by 4.8%after acid pickling,and increase by 16.2%through vanadium load.The water washing and acid pickling process can both wash away part of the K and Na elements in the catalyst.The acid pickling effect is better than water washing.The mass fraction of K decreases by 24.3%,and the mass fraction of Na decreases by 29.9%.The compressive strength of the catalyst decreases with the increase of ultrasonic time and frequency and contact surface.(3)The additive A has a better load capacity of coating than additive K.When its dosage is 5%,the drying temperature is 80? and the drying time is 8h,the catalyst coating has the highest load capacity and the best bonding strength.