Patent ID: 6164064
Filing Date: 2000-12-26
Classification: B01D,F01N,F02B,F02D

Abstract:
A method for desulfurizing an NOx reservoir catalyst in the exhaust line of an internal combustion engine comprising the following steps:a) detecting a need for desulfurizing an NOx reservoir catalyst,b) initiating and carrying out an exhaust gas temperature-raising procedure whereby the NOx reservoir catalyst is heated to a temperature at least as high as a predetermined desulfurizing temperature and below a predetermined maximum NOx reservoir catalyst temperature;c) determining whether the ageing temperature of the NOx reservoir catalyst has been exceeded or the rate of temperature increase in the neighborhood of the ageing threshold is so high that a temperature increase above the ageing threshold can be anticipated and, if so, reducing the exhaust gas temperature-raising procedure;d) desulfurizing the NOx reservoir catalyst by rich operation of the engine; ande) restoring normal operation of the engine after completion of the desulfurizing step.