The Preparation Technology And Performance Evaluation Of Monolithic SCR Catalyst

In this paper, the preparation technology of monolithic SCR catalyst including high temperature co-blend honeycomb catalyst and low temperature coating honeycomb catalyst was investigated. In the molding process of high temperature co-blend honeycomb catalyst, liquid powder ratio, the addition and type of adhesive, lubricant and strengthening agent have a great influence on molding properties of the catalysts. The influence of molding process, drying process and calcination method on the mechanical strength and catalytic activity was discussed. After testing, the mechanical strength of catalyst was4MPa and the highest catalytic activity could reach83%. In the molding process of low temperature coating honeycomb catalyst, the influence of the catalyst particle size distribution, the slurry solid content, pH value, viscosity, adhesion agent, surface active agent on the performance of the catalyst slurry was investigated. The geometric surface area and water absorption of honeycomb ceramic have a great influence on the coating performance. Cordierite honeycomb ceramics after ultrasonic coating two times could prepare the low temperature coating honeycomb catalyst with good performance, whose coating rate was20%and off rate was only5%. The denitration efficiency of low temperature monolith catalyst reached73%under the condition:the molar ratio of ammonia to NOx is1, the temperature is150℃, SV is10000h-1.