POST THERMAL CONTROL DEVICE FOR USE WITH A NOx SLIP CATALYST

An exhaust gas treatment system for use in reducing NOx in an exhaust gas stream of a diesel-engine vehicle, the system comprising:

• a diesel oxidation catalyst (DOC);
• a mixer fluidly coupled to the DOC;
• a diesel particulate filter (DPF) fluidly coupled to the mixer and DOC;
• a thermal control device (TCD) positioned after the DPF;
• a NOx slip catalyst (NSC) positioned downstream from the DPF;
• and,
• at least one temperature sensor (TS) positioned in conjunction with one of the TCD and NSC, wherein the TCD operates in conjunction with the at least one temperature sensor to reduce the temperature of the exhaust gas stream prior to entry into the NSC.

A method for reducing NOx in an exhaust gas stream in a diesel-engine vehicle after particulate filter regeneration, the method comprising:

• fluidly coupling components of an exhaust gas treatment system package to an engine exhaust gas system;
• applying superheated exhaust gas into the exhaust gas treatment system package for filter regeneration;
• injecting gaseous ammonia into the exhaust gas treatment system package for NOx reduction;
• incorporating a NOx slip catalyst (NSC) into the exhaust gas treatment system;
• reducing the temperature of the exhaust gas prior to entry into the NSC;
• and,
• further reducing the level of NOx to an acceptable level.