SCR & CO Catalyst Systems

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SCR & CO Catalyst Systems

Selective catalytic reduction converts nitrogen oxides (also referred to as NOx) with the aid of a catalyst into diatomic nitrogen and water. Typically, anhydrous ammonia, aqueous ammonia or urea is injected into the flue gas or exhaust gas, then absorbed onto the catalyst. If the catalyst is not kept clean and the ammonia injection system is not tuned, ammonia slip occurs. The combination of the contaminants in the fuel and the ammonia slip can lead to formation of ammonia salts downstream, where they plate out or deposit onto the gas side of the fin tubes, thus reducing heat transfer efficiency and promoting corrosion on the back end of the HRSG.

Catalyst prior to cleaning

Catalyst after cleaning

Minimizing Plugging & Deactivation of SCR Catalysts

In addition to the cleaning services for removing the fouling or ammonia deposits from the fin tubes, EAI also offers cleaning methods and services to clean the SCR, SCO and CO catalyst modules to aid in reducing back pressure and keep the reactive surfaces of the catalyst clean so that it can perform with rapid deactivation.

The rust, dust, and debris that are transported in the exhaust gas can plug the catalyst modules, causing significant increases in back pressure and reducing the capacity of the plant. Insulation failures upstream of the catalyst can also quickly cover the catalyst surface and choke off the flow through the HRSG. EAI can quickly and efficiently clean the catalyst walls to eliminate these performance-robbing conditions.