Ammonia tungsten oxide systems

Selective Catalytic Reduction (SCR) process is very similar to SNCR with the exception that a catalyst is used to accelerate the reactions at lower temperatures allowing it to be applied to both full and partial-burn regenerators. An SCR system consists of a catalyst bed installed in the flue gas line of a combustion system. Ammonia is injected into the flue gas with air in the presence of a catalyst. The catalyst is typically oxide forms of vanadium and tungsten. The ammonia selectively reacts with NOx to form molecular nitrogen and water via an exothermic reaction that has achieved > 90% reduction in NO when applied to an FCCU. 

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