Nitrogen oxide (NOx) reduction by the selective catalytic reduction (SCR) system assisted by an oxidation precatalyst is modelled and analytically investigated. The Langmuir—Hinshelwood SCR kinetic scheme with vanadium-based catalyst and ammonia (NH3) reductant in conjunction with the NO—NO2 conversion reaction over a platinum-based catalyst is used. The effects of the ratio of the oxidation precatalyst to the SCR monolith volume, the gas temperature, the space velocity, and the NH3-to-NOx concentration ratio on the de-NOx performance are parametrically examined. The oxidation precatalyst promotes NOx conversion at low temperatures. At intermediate temperatures, the NOx reduction is either activated or deactivated with increase in the space velocity. A higher oxidation precatalyst-to-SCR monolith volume ratio tends to promote the NOx reduction of higher space velocities. At high temperatures, the de-NOx efficiency is very high and insensitive to the space velocity. The NOx conversion efficiency depends on the NH3-to-NOx ratio at low temperatures.
Modelling and parametric investigation of NOx reduction by oxidation precatalyst-assisted ammonia-selective catalytic reduction
2009-09-01
14 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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