Availability of NH3 adsorption in vanadium-based SCR for reducing NOx emission and NH3 slip

Abstract This study was carried out to analyze the amount of NH 3 adsorption by selective catalytic reduction using various methods for the development of an optimized urea injection control logic. The maximum adsorbable amount, available adsorption amount for NOx reduction, and maximum adsorption amount before NH 3 slip were separately measured. The results of the three types of adsorption amounts show that the optimum operating range for urea control gradually narrowed for high exhaust gas temperatures. Furthermore, it was found to be particularly challenging to completely remove NH 3 slip without ammonia oxidation catalyst in the transient operation of the engine.