Supplemental ammonia storage and delivery system

A supplemental NOx reduction device for use in an exhaust after-treatment system, the device comprising:

• a refillable canister having a supply of ammonia;
• a heating element coupled to the refillable canister;
• a flow control module connected to the refillable canister for regulating the discharge of
• ammonia from the refillable canister;
• tubing for fluidly connecting the refillable canister with a vehicle exhaust;
• an injection system connected to the tubing for injecting ammonia into the vehicle exhaust;
• a sensor system for determining relevant operating conditions and sending inputs representative of the conditions;
• and an electronic control module for receiving sensor inputs and activating the flow control module based on sensor inputs, wherein the device is coupled to a vehicle exhaust line upstream of a DPF.

A method for reducing NOx in an exhaust stream, the method comprising the steps of:

• determining a need for NOx reduction in an exhaust stream;
• determining temperature of exhaust stream;
• and
• injecting at least one of a primary reductant and a secondary reductant into the exhaust stream based on the determined temperature of the exhaust stream.