Hybrid SNCR/SCR Systems for NOx reduction

In recent years, new NOx control hybrid systems, using a combination of SNCR and SCR technology, have been developed. These hybrid systems reduce the level of nitrogen oxides (NOx) in fossil fuel combustion flue gas with a selective non-catalytic reduction (SNCR) treatment stage followed by a selective catalytic reduction (SCR) treatment stage.

Why choose a hybrid SNCR/SCR system?

A hybrid system may be an interesting alternative versus installing a single SCR system. Hybrid systems help to find a balance between investment costs (CAPEX) and operating costs (OPEX). This is particularly useful for cases where:

• A significant reduction in NOx emissions is expected, yet flexibility of operation is needed.
• The installation space available for the catalyst is restricted.
• Increasing the pressure drop is critical or leads to higher operational costs and significant investments.

In such cases, the hybrid solution is the best choice: it reduces the size of the catalyst to be installed, thus reducing investment, and volume issues at the site.

If you have questions about SCR/SNCR hybrid systems, please contact our experts on NOx control.