Catalytic removal of N2O in model flue gases of a nitric acid plant using a promoted Fe zeolite

Three options for removal of N2O using a promoted Fe-ZSM-5 catalyst have be en explored under conditions representative for the off gases of a nitric a cid plant: catalytic decomposition and selective catalytic reduction (SCR) using propane or methane as a reductant. Catalytic decomposition of N2O tak es place at temperatures above 400 degreesC at a space velocity of 10,000 h (-1). The addition of propane lowers the temperature for N2O conversion wit h about 100 degreesC, In propane-assisted SCR of N2O, the emissions of unre acted hydrocarbons and of CO are low and also NOx reduction takes place. Me thane is more difficult to be activated by the catalyst, which causes lower N2O destruction efficiency and the output of unreacted methane. In all cas es, N2O conversion is higher at elevated pressure. (C) 2001 Elsevier Scienc e B,V. All rights reserved.