Physical based LNT regeneration strategy

A method of operating a power generation system, comprising:

• operating a diesel engine to produce a lean exhaust comprising NOX;
• passing the lean exhaust through an exhaust aftertreatment system comprising a lean NOX trap;
• operating the exhaust aftertreatment system in lean phases during which the lean NOX trap adsorbs a portion of the NOX from the exhaust;
• and
• selectively denitrating the lean NOX trap in rich phases based on both a first and a second criteria being met;
• wherein the first criteria is a threshold amount of NOX stored in the NOX trap, a threshold saturation of the NOX trap, or remaining a threshold NOX storage capacity remaining in the NOX trap;
• the second criteria is one or more measurements of NOX concentration in the exhaust showing that the lean NOX trap, or the lean NOX trap in combination with one or more other devices, has reached a threshold level for NOX removal efficiency or effectiveness at limiting NOX emissions;
• during the lean phase if only one criteria is met, the other criteria is recursively examined and the lean phase continued at least until the other criteria is also met;
• and
• the rich phases comprise providing an overall rich exhaust-reductant mixture to the lean NOX trap, whereby the lean NOX trap releases and reduces stored NOX.