Search Results

Since a NOx trap catalyst cyclically releases and reduces NOx with rich exhaust gas, generating of a rich spike becomes important for application to diesel engines, which always operate with overall lean combustion. In addition, a NOx trap catalyst is poisoned and degraded in performance by the presence of SO2 in the exhaust gas. When the NOx absorbing efficiency thus decreases, it is necessary to regenerate the catalyst by a sulfur purge (desulfation) process in order to remove SO2. It is apparent that there are many factors and effects to understand before one can apply this catalyst system to a diesel engine, therefore we have carried out an inquiry into a performance of the NOx catalyst used the model gas equipment with known gas mixtures. The rich spike was generated with diesel fuel (light oil), resulting in a transient equivalence ratio spike > 1, to simulate diesel exhaust gas.