Patent ID: 7036489

Claim:
A method for operating an exhaust system, comprising: determining a stream temperature of an exhaust stream; desulfating the NOx adsorber, wherein desulfating comprises determining an amount of oxygen needed to increase an initial temperature of a NOx adsorber to a desulfation temperature of greater than or equal to about 600° C.; producing reformate comprising hydrogen and carbon monoxide in an on-board reformer; introducing the amount of oxygen to the NOx adsorber; and introducing a sufficient amount of reformate to the NOx adsorber to attain an air to fuel ratio that is less than a combustion stoichiometric ratio; wherein the oxygen and reformate react, creating an exotherm and increasing the temperature of the NOx adsorber to the desulfation temperature, and wherein, at the desulfation temperature, a sulfur material in the NOx adsorber is released and reacts with the reformate.