Performance of Fe-Ni-W exchanged zeolite for NOx reduction with NH3 in a lab-scale circulating fluidized bed

Selective non-catalytic reduction of NOx (SNCR) with NH 3 is commonly used in industrial facilities like circulating fluidized bed (CFB) furnaces. However, the strongly temperature-dependent de-NOx feature confines its applications in a specific temperature range (900–1050 °C). Here, we report a new strategy on using Fe-Ni-W exchanged zeolite (0.5FNW-H) as a catalyst to extend the SNCR temperature window. In the CFB reactor, a significant NOx conversion improvement ranging from 14.1% to 80.9% was achieved at 700 to 850 °C by applying the developed catalyst. Catalyst dosage of 4500 h −1 (GHSV), a particle diameter of 0.1–0.3 mm, and NH 3 injection position at the dense-phase zone were found preferred for NOx reduction with the highest efficiency of ~85% at 700 °C. The physicochemical properties of the catalysts remained stable after the circulating reactions in the CFB reactor. The developed catalyst is particularly applicable for improving the SNCR performance when the thermal power plants are operated at low loads.