SCR (Selective Catalytic Reduction)
It is a system of removing flue gas included in NOx by using catalysts and reducing to high efficiency.
Through reduction reaction of NH3 and NOx of gas supplied through AIG (Ammonia Injection Grid) installed at the front of the catalyst layer, it is classified into N2 and H20.
By injecting and mixing in the flue gas the reductant (NH3 or Urea etc.) of NOx and by passing this mixed gas from the upper part of the reactor with temperatures of 200~400 degrees, it is passed through the catalyst player. NOx is reduced and nitrogen (N2) and water (H20) harmful to the human body is decomposed. The NOx control efficiency due to this process has a difference according to catalyst type, injected ammonia quantity, initial NOx concentration and catalyst life expectancy, but has 80~90% efficiency at optimized operating conditions.
It is usually applied to fixed sources such as incinerators, oil and coal, and there are no byproducts. As the composition of the equipment too is comparatively simple with reductant being injects after installing the catalyst layer reactor, it is appropriate for large capacity flue gas processing and it is generally used as gas denigration device of generation use boiler.
DE-NOx System
Processing Nitrogen Oxides of Flue Gas Emitted from Incinerator
| Generative Deterrent Technology |
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|---|---|
| Removal Technology |
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Differences between SCR and SNCR
| Classification | SCR(Selecive Catalytic Reduction) | SNCR(Selecive Non-Catalytic Reduction) |
|---|---|---|
| Dioxin | NH3, Urea Water, TiO2, V202 etc. | None |
| Operating Temperature | 200~400℃(280~350℃) | 900~1100℃(950~1000℃) |
| Efficiency | Approx. 80~90% | Approx. 40~50% |
| Installation/Maintenance Cost (Application Target) |
High Costs (Applied to facilities operated serially) | Low Cost (applied to small amount within 200MV) |
| Other | Dioxin can be removed according to the dioxin | |
| Reductant | NH3, CO, H2S |
