# US 10,767,529 B2 · Automotive exhaust aftertreatment system having onboard ammonia reactor with heated doser > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,767,529 B2 - Document ID: US10767529B2 - Status: Granted - Kind: B2 - Application number: 16/184,534 - Filed: 2018-11-08 - Published: 2020-05-14 - Granted: 2020-09-08 - Earliest claimed: 2018-11-08 - Assignees: Faurecia Emissions Control Technologies, USA, LLC - Applicants: Faurecia Emissions Control Technologies, USA, LLC - Inventors: Edward Kinnaird; John Rohde - Web page: https://patentgrep.com/patent/US10767529B2 ## CPC - F01N 3/2066: {Selective catalytic reduction [SCR]} - B01D 53/9431: {Processes characterised by a specific device} - F01N 3/2006: {Periodically heating or cooling catalytic reactors, e.g. at cold starting or overheating (by electrically controlling the supply of combustible mixture or its constituents only F02D41/0235)} - F01N 3/208: {Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent} - F01N 3/2892: {Exhaust flow directors or the like, e.g. upstream of catalytic device} - F01N 9/00: Electrical control of exhaust gas treating apparatus (monitoring or diagnostic devices for exhaust-gas treatment apparatus F01N11/00; conjoint electrical control of two or more combustion engine functions F02D43/00) - F01N 11/00: Monitoring or diagnostic devices for exhaust-gas treatment apparatus - F01N 2240/16: an electric heater, i.e. a resistance heater - F01N 2240/20: a flow director or deflector - F01N 2240/25: an ammonia generator - F01N 2240/40: a hydrolysis catalyst - F01N 2590/08: for heavy duty applications, e.g. trucks, buses, tractors, locomotives - F01N 2610/02: the substance being ammonia or urea - F01N 2610/10: the substance being heated, e.g. by heating tank or supply line of the added substance - F01N 2610/105: Control thereof - F01N 2610/1406: Storage means for substances, e.g. tanks or reservoirs - F01N 2610/1453: Sprayers or atomisers; Arrangement thereof in the exhaust apparatus - F01N 2610/146: Control thereof, e.g. control of injectors or injection valves - Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters - Y02T 10/12: Improving ICE efficiencies - Y02T 10/40: Engine management systems - F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An automotive exhaust aftertreatment system includes an onboard ammonium carbamate reactor. The onboard ammonium carbamate reactor is coupled to a diesel emission fluid reservoir also included in the system and is configured to generate aqueous ammonium carbamate solution from diesel emission fluid. A doser configured to inject the generated aqueous ammonium carbamate solution has integrated heating. ## Claims ### Claim 1 An exhaust gas aftertreatment system for dosing reducing agent into an exhaust stream, the system comprising a diesel emission fluid reservoir, a reactor for generating an ammonia solution from diesel emission fluid in the diesel emission fluid reservoir, a doser configured to discharge controlled amounts of the ammonia solution into an exhaust stream moving through the exhaust gas aftertreatment system, a heating system configured to manage temperatures within the doser, the heating system including a passive doser heat exchanger configured to withdraw heat from exhaust gasses passing through the exhaust aftertreatment system and heat passageways through the doser, an active doser heating element configured to produce heat from electrical energy supplied to the heating system and heat passageways through the doser, and a heating system controller configured to selectively apply heat from the active doser heating element to manage the temperature of the ammonia solution moving in passageways through the doser, a sensor configured to detect a parameter associated with the amount of NOx carried in an exhaust stream entering the exhaust aftertreatment system, a doser controller configured to inject the ammonia solution at a predetermined reaction flow rate into the exhaust stream based at least in part on the amount of NOx detected, an ammonium carbamate reservoir configured to store aqueous ammonium carbamate generated by the ammonium carbamate reactor, and a reservoir level sensor configured to detect an amount of aqueous ammonium carbamate solution in the ammonium carbamate reservoir, wherein the doser controller is configured to inject aqueous ammonium carbamate solution at a relief flow rate into the exhaust stream greater than the predetermined reaction flow rate when the amount of aqueous ammonium carbamate solution in the ammonium carbamate reservoir is greater than a predetermined amount. ### Claim 2 (depends on 1) The system of claim 1, wherein the heating system controller is configured to selectively modulate heat from the passive doser heat exchanger to manage the temperature of aqueous ammonium carbamate solution moving in passageways through the doser. ### Claim 3 (depends on 2) The system of claim 2, wherein the heating system controller is configured to selectively apply heat from the active doser heating element and to selectively modulate heat from the passive doser heat exchanger so as to manage the temperature of the ammonia solution discharged from the doser above 60 degrees Celsius. ### Claim 4 (depends on 3) The system of claim 3, wherein the heating system controller is configured to selectively apply heat from the active doser heating element and to selectively modulate heat from the passive doser heat exchanger so as to manage the temperature of the ammonia solution discharged from the doser between about 60 degrees Celsius and about 200 degrees Celsius. ### Claim 5 (depends on 1) The system of claim 1, further comprising a catalyst mounted within the system, and wherein the passive doser heat exchanger withdraws heat from exhaust gasses downstream of the catalyst so as not to reduce exhaust gas temperatures before interaction with the catalyst. ### Claim 6 (depends on 5) The system of claim 5, wherein the heating system includes a passive reactor heat exchanger configured to withdraw heat from exhaust gasses passing through the exhaust aftertreatment system and heat contents of the reactor, an active reactor heating element configured to produce heat from electrical energy supplied to the heating system and heat contents of the reactor, and a heating system controller configured to selectively apply heat from the active reactor heating element to manage the temperature within the reactor. ### Claim 7 (depends on 6) The system of claim 6, wherein the passive reactor heat exchanger withdraws heat from exhaust gasses downstream of the catalyst so as not to reduce exhaust gas temperatures before interaction with the catalyst. ### Claim 8 An exhaust gas aftertreatment system for dosing reducing agent into an exhaust stream, the system comprising a diesel emission fluid reservoir, a reactor for generating an ammonia solution from diesel emission fluid in the diesel emission fluid reservoir, a doser configured to discharge controlled amounts of the ammonia solution into an exhaust stream moving through the exhaust gas aftertreatment system, and a heating system configured to manage temperatures within the doser, the heating system including a passive doser heat exchanger configured to withdraw heat from exhaust gasses passing through the exhaust aftertreatment system and heat passageways through the doser, an active doser heating element configured to produce heat from electrical energy supplied to the heating system and heat passageways through the doser, and a heating system controller configured to selectively apply heat from the active doser heating element to manage the temperature of the ammonia solution moving in passageways through the doser, wherein the heating system includes an active reservoir heating element configured to produce heat from electrical energy supplied to the heating system and heat contents of the ammonium carbamate reservoir, and wherein the heating system controller configured to selectively apply heat from the active reactor heating element to manage the temperature within the ammonium carbamate reservoir to maintain equilibrium of stored aqueous ammonium carbamate solution. ### Claim 9 (depends on 8) The system of claim 8, wherein the heating system includes a passive reservoir heat exchanger configured to withdraw heat from exhaust gasses passing through the exhaust aftertreatment system and heat contents of the ammonium carbamate reservoir, and wherein the heating system controller is configured to selectively modulate heat from the passive reservoir heat exchanger to control the temperature within the ammonium carbamate reservoir to maintain equilibrium of stored aqueous ammonium carbamate solution. ### Claim 10 A vehicle comprising a combustion engine configured to generate exhaust gases, and an exhaust aftertreatment system configured to treat the exhaust gases, the exhaust aftertreatment system including a diesel emission fluid reservoir, a reactor for generating an ammonia solution from diesel emission fluid in the diesel emission fluid reservoir, a doser configured to discharge controlled amounts of the ammonia solution into an exhaust stream moving through the exhaust gas aftertreatment system, and a heating system configured to manage temperatures within the doser, the heating system including a passive doser heat exchanger configured to withdraw heat from exhaust gasses passing through the exhaust aftertreatment system and heat passageways through the doser, an active doser heating element configured to produce heat from electrical energy supplied to the heating system and heat passageways through the doser, and a heating system controller configured to selectively apply heat from the active doser heating element to manage the temperature of the ammonia solution moving in passageways through the doser, wherein the reactor includes a relief valve in fluid communication with the diesel emission fluid reservoir and configured to allow the removal of diesel emission fluid from the reactor to the diesel emission fluid reservoir.