Method for heating solid ammonia to release gaseous ammonia in exhaust aftertreatment system

Abstract

A method for heating solid ammonia (NH 3 ) in a main unit ( 12 ) to deliver gaseous ammonia into the exhaust gas (EG) downstream of an engine ( 16 ) includes the steps of diverting at least a portion of the exhaust gas from the exhaust gas passageway ( 14 ), fluidly communicating the exhaust gas on a delivery line ( 28 ) from the exhaust gas passageway to the main unit, heating the solid ammonia with the exhaust gas, and fluidly communicating the exhaust gas on a return line ( 30 ) from the main unit to the exhaust gas passageway.

1 ) A method for heating solid ammonia (NH 3 ) in a main unit to deliver gaseous ammonia into exhaust gas downstream of an engine, the method comprising:
 providing engine coolant that is dedicated only to heating the solid ammonia;   heating the dedicated engine coolant at a heater;   fluidly communicating the engine coolant on a delivery line from the heater to the main unit;   heating the solid ammonia with the heated engine coolant; and   fluidly communicating the engine coolant on a return line from the main unit to the heater.   
     
     
         2 ) The method of  claim 1  wherein the heated engine coolant heats the solid ammonia to a temperature of at least about 150-degrees Celsius for the eighth molecule of gaseous ammonia to be released from the solid ammonia. 
     
     
         3 ) The method of  claim 1  wherein the heater is a thermo-electric heater that uses the Peltier effect to heat the engine coolant. 
     
     
         4 ) The method of  claim 1  wherein the heater is an electric heater. 
     
     
         5 ) The method of  claim 1  further comprising storing the solid ammonia inside an NH3 cartridge that is disposed inside of the main unit. 
     
     
         6 ) The method of  claim 1  further comprising controlling the temperature of the engine coolant with a control unit. 
     
     
         7 ) The method of  claim 1  further comprising sensing the temperature of the engine coolant with a sensor. 
     
     
         8 ) A method for heating solid ammonia (NH 3 ) in a main unit to deliver gaseous ammonia into exhaust gas in an exhaust gas passageway downstream of an engine, the method comprising:
 diverting at least a portion of the exhaust gas from the exhaust gas passageway;   fluidly communicating the exhaust gas on a delivery line from the exhaust gas passageway to the main unit;   heating the solid ammonia with the exhaust gas; and   fluidly communicating the exhaust gas on a return line from the main unit to the exhaust gas passageway.   
     
     
         9 ) The method of  claim 8  wherein the heated exhaust gas heats the solid ammonia to a temperature of at least about 150-degrees Celsius for the eighth molecule of gaseous ammonia to be released from the solid ammonia. 
     
     
         10 ) The method of  claim 8  further comprising the step of diverting the exhaust gas downstream of an aftertreatment device. 
     
     
         11 ) The method of  claim 10  further comprising the step of returning the exhaust gas downstream of the aftertreatment device. 
     
     
         12 ) The method of  claim 8  further comprising storing the solid ammonia inside an NH3 cartridge that is disposed inside of the main unit. 
     
     
         13 ) A method for heating solid ammonia (NH 3 ) in a main unit to deliver gaseous ammonia into exhaust gas downstream of an engine, the method comprising:
 providing at least one of engine oil and transmission oil;   fluidly communicating the oil on a delivery line from the at least one of the engine and the transmission to the main unit;   heating the solid ammonia with the heated oil; and   fluidly communicating the oil on a return line from the main unit to the at least one of the engine and the transmission.   
     
     
         14 ) The method of  claim 13  further comprising storing the solid ammonia inside an NH3 cartridge that is disposed inside of the main unit. 
     
     
         15 ) The method of  claim 13  further comprising controlling the temperature of the oil with a control unit. 
     
     
         16 ) The method of  claim 13  further comprising sensing the temperature of the oil with a sensor. 
     
     
         17 ) A method for heating solid ammonia (NH 3 ) to deliver gaseous ammonia into exhaust gas downstream of an engine, the method comprising:
 embedding an electric coil into the solid ammonia;   heating the electric coil with an electrical heater; and   attaching the electric coil to the electric heater with at least one wire.   
     
     
         18 ) The method of  claim 17  further comprising embedding the electric coil inside of an NH 3  cartridge. 
     
     
         19 ) The method of  claim 17  further comprising controlling the temperature of the embedded coil with a control unit. 
     
     
         20 ) The method of  claim 17  further comprising sensing the temperature of the solid ammonia with a sensor.