Introduction and Factors of Selective Catalytic Reduction (SCR) Catalysts

Selective catalytic reduction (SCR) catalysts utilize a reducing agent to selectively react with NOx in flue gas, producing non-toxic and pollution-free N2 and H2O, under the action of a catalyst.

Reaction temperature determines not only the reaction rate of the reactants but also the reactivity of the SCR catalyst. Generally, higher reaction temperatures result in faster reaction rates and higher catalyst activity, leading to a smaller reaction space and reactor volume per unit area. Considering reactant heating, system control, and the catalyst's suitable temperature range, SCR system temperatures are typically set between 320 and 420°C.

Space velocity is a key design parameter for selective catalytic reduction (SCR) catalysts. It measures the residence time of flue gas (wet flue gas under standard conditions) within the catalyst volume, and to some extent determines whether the reactants react completely. It also influences the scouring of the reactor catalyst framework and the friction loss of the flue gas.

The quality of the flue gas flow pattern determines the effectiveness of the catalyst. A suitable flue gas flow pattern not only maximizes catalyst utilization but also reduces friction loss. In engineering design, the flue gas flow field must be carefully considered. Ammonia injection points should have turbulent conditions to achieve optimal mixing with the flue gas and form a clearly defined homogeneous flow region.