Technical Paper
Initial Evaluations of Injector Compatibility with an Alternative SCR Reductant Carrier - Guanidinium Formate
2014-04-01
2014-01-1532
The implementation of stringent nitrogen oxides (NOx) emissions reduction legislation in Europe and North America is driving the introduction of new exhaust aftertreatment systems, including those that treat NOx under the high-oxygen conditions typical of lean-burn engines. One increasingly common solution, referred to as Selective Catalytic Reduction (SCR), comprises a catalyst that facilitates the reactions of ammonia (NH3) with the exhaust nitrogen oxides (NOx) to produce nitrogen (N2) and water (H2O). It is customary with these systems to use a liquid aqueous urea solution, typically at a 32% concentration of urea (CO(NH2)2). The solution is referred to as AUS-32, and is also known under its commercial name of AdBlue® in Europe, and DEF - Diesel Exhaust Fluid - in the USA. The urea solution is injected into the exhaust and transformed to NH3 by various mechanisms for the SCR reactions.