Absorption Plus Selective Catalytic Reduction

Monsanto Enviro-Chem offers NOx abatement technology that is licensed from Rhodia of France. It includes a High Efficiency Absorption (HEA) section for extended absorption and a catalytic reduction section (SCR) for Catalytic Destruction ofNOx (i.e., the DCN technology)99. 

The HEA technology is based on the enhanced oxidation of the nitrous acid (HN02) intermediate in the liquid phase. Conventional absorption technology is based upon the partial oxidation of the HN02 intermediate, which evolves nitrogen monoxide (NO) gas. This must be reoxidized to nitrogen dioxide (N02) in a relatively slow gas phase reaction99. 

With Rhodia s high activity catalyst in the DCN process, efficient catalytic reduction ofNOx to nitrogen and water is possible at temperatures as low as 180°C without measurable ammonia in the tail gas. This catalyst has operated for over 10 years in some installations . 

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