# US 2014/0360186 A1 · Method and device for desulphurizing an exhaust-gas recirculation flow > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0360186 A1 - Document ID: US20140360186A1 - Status: Published application - Kind: A1 - Application number: 14/283,656 - Filed: 2014-05-21 - Published: 2014-12-11 - Earliest claimed: 2013-06-07 - Assignees: Man Truck & Bus AG - Applicants: MAN Truck & Bus AG - Inventors: Andreas DOERING - Web page: https://patentgrep.com/patent/US20140360186A1 ## CPC - F02M 26/15: in relation to engine exhaust purifying apparatus - F01N 3/2066: {Selective catalytic reduction [SCR]} - F02M 26/50: Arrangements or methods for preventing or reducing deposits, corrosion or wear caused by impurities (arrangement or layout of EGR passages with means for cleaning or treating the recirculated gases F02M26/35; protection of EGR valves from damage F02M26/74) - F01N 2610/02: the substance being ammonia or urea - F02B 29/0406: {Layout of the intake air cooling or coolant circuit} - F02B 37/18: by bypassing exhaust {from the inlet to the outlet of turbine or to the atmosphere} - F02M 26/05: High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor - F02M 26/06: Low pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust downstream of the turbocharger turbine and reintroduced into the intake system upstream of the compressor - F02M 26/07: Mixed pressure loops, i.e. wherein recirculated exhaust gas is either taken out upstream of the turbine and reintroduced upstream of the compressor, or is taken out downstream of the turbine and reintroduced downstream of the compressor - F02M 26/23: Layout, e.g. schematics - Y02T 10/12: Improving ICE efficiencies - F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF - 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) - F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G) - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract A method for desulphurizing an exhaust-gas recirculation flow of an internal combustion engine supplied to the internal combustion engine on the fresh-air side includes branching a partial exhaust-gas flow from the exhaust-gas flow of the internal combustion engine. At least one reactant is supplied to the partial exhaust-gas flow that splits to form ammonia, and the thus laden partial exhaust-gas flow is supplied partially, as an exhaust-gas recirculation flow, to the fresh-air side and partially, as an aftertreatment partial flow, to an exhaust-gas aftertreatment system. The flow rate of the exhaust-gas recirculation flow supplied to the fresh-air side and the flow rate of the aftertreatment partial flow supplied to the exhaust gas aftertreatment system are predefined and/or varied by a regulating device as a function of at least one operating parameter that defines the respective operating state of the internal combustion engine. ## Claims ### Claim 1 A method for desulphurizing an exhaust-gas recirculation flow of an intern& combustion engine, said exhaust-gas recirculation flow being supplied to a fresh-air side of the internal combustion engine, and ammonia being used for the desuiphurization, the method comprising the steps of: branching off a first partial exhaust-gas flow from the exhaust-gas flow of the internal combustion engine; supplying to the first partial exhaust-gas flow at least one reactant that splits to form ammonia to form a laden exhaust-gas flow; branching the laden exhaust gas flow into an exhaust-gas recirculation flow and an aftertreatment partial flow; supplying the exhaust-gas recirculation flow he fresh-air side of the internal combustion engine; supplying the aftertreatment partial flow to an exhaust-gas aftertreatment system; and predefining or varying flow rates of the exhaust-gas recirculation flow and the aftertreatment partial flow as a function of at least one operating parameter defining a respective operating state of the internal combustion engine. ### Claim 2 (depends on 1) The method of claim 1, wherein the internal combustion engine is supercharged by an exhaust-gas turbocharger, and wherein the first partial exhaust gas flow is branched off from the exhaust-gas flow of the internal combustion engine upstream of a turbine of the exhaust-gas turbocharger. ### Claim 3 (depends on 1) The method of claim 1, wherein the aftertreatment partial flow is conducted to an SCR catalytic converter. ### Claim 4 (depends on 3) The method of claim 3, further comprising: branching off a further exhaust-gas partial flow from the aftertreatment partial flow downstream of the SCR catalytic converter; feeding the further exhaust-gas partial flow to the fresh-air side of the internal combustion engine; and regulating a flow rate of the further exhaust-gas partial flow as a function of at least one of a flow rate of the exhaust-gas recirculation flow supplied to the fresh-air side, a flow rate of the aftertreatment partial flow through the SCR catalytic converter, and at least one operating parameter that defines a respective operating state of the internal combustion engine. ### Claim 5 (depends on 2) The method of claim 2, further comprising: branching off a further exhaust-gas partial flow upstream of the turbine of the turbocharger; feeding the further exhaust-gas partial flow to the fresh-air side of the internal combustion engine; and regulating a flow rate of the further exhaust-gas partial flow as a function of at least one of a flow rate of the exhaust-gas recirculation flow supplied to the fresh-air side, a flow rate of the aftertreatment partial flow supplied to an exhaust-gas aftertreatment system, and at least one operating parameter that defines a respective operating state of the internal combustion engine. ### Claim 6 (depends on 5) The method of claim 5, further comprising cooling the further exhaust-gas partial flow prior to said step of feeding the further exhaust-gas partial flow to the fresh-air side. ### Claim 7 (depends on 1) The method of claim 1, further comprising breaking down the at least one reactant in at least one catalytic converter through which the laden exhaust-gas flow is conducted. ### Claim 8 (depends on 7) The method of claim 7, wherein the catalytic converter comprises as active components at least one of the following compounds or elements, and oxide forms thereof: titanium, silicon, vanadium, tungsten, iron, aluminum, gold, and zeolites. ### Claim 9 (depends on 1) The method of claim 1, wherein the flow rates of the exhaust-gas recirculation flow to the fresh-air side and of the aftertreatment partial flow to an exhaust-gas aftertreatment system are each regulated by at least one throttle device. ### Claim 10 (depends on 2) The method of claim 2, wherein the laden exhaust-gas flow is supplied to the fresh-air side upstream of a compressor of the turbocharger. ### Claim 11 (depends on 2) The method of claim 2, wherein the laden exhaust-gas flow is supplied to the fresh-air side downstream of a compressor of the turbocharger. ### Claim 12 (depends on 2) The method of claim 2, wherein the laden exhaust-gas flow is supplied to the fresh-air side downstream of coolers installed in the fresh-air side. ### Claim 13 (depends on 1) The method of claim 1, wherein a supplied ammonia flow rate is regulated as a function of at least four of the following operating parameters: sulphur content of the fuel, air/fuel ratio, charge pressure, air humidity, recirculated exhaust-gas flow rate (EGR rate), untreated NOx emissions, setpoint NOx concentration, and temperature of an SCR catalytic converter. ### Claim 14 A device for desulphurizing an exhaust-gas recirculation flow supplied to a fresh-air side of the internal combustion engine, the device comprising: a first branch line that branches off from an exhaust line of the internal combustion engine that lead to an exhaust-gas aftertreatment system; a supply device coupled to the first branch line and supplying at least one reactant that splits to form ammonia, wherein the first branch line recirculates an ammonia laden exhaust-gas recirculation flow; a second branch line that branches off from the first branch line and recirculates a part of the laden exhaust-gas recirculation flow into the exhaust gas aftertreatment system; and a regulating device that at least one of predefines or varies a flow rate of the exhaust-gas recirculation flow supplied to the fresh air side and a flow rate of the aftertreatment partial flow supplied to the aftertreatment system as a function of at least one operating parameter that defines an operating state of the internal combustion engine. ### Claim 15 (depends on 14) The device of claim 14, wherein the internal combustion engine has a turbocharger, and the first branch line branches off of the exhaust line upstream of a turbine of the turbocharger. ### Claim 16 (depends on 15) The device of claim 15, further comprising a third branch line that branches off from the exhaust line and is connected to a fresh-air line of the internal combustion engine via a heat exchanger. ### Claim 17 (depends on 16) The device of claim 16, wherein a high-pressure side of a compressor of the turbocharger and the first branch line are connected to the fresh-air line. ### Claim 18 (depends on 14) The device of claim 14, further comprising a further branch line that branches off from the exhaust line downstream of the aftertreatment system and is supplied to the fresh-air side. ### Claim 19 (depends on 18) The device of claim 18, wherein the further branch line is supplied to the first branch line. ### Claim 20 (depends on 15) The device of claim 15, wherein the laden exhaust-gas flow is supplied to the fresh-air side upstream of a compressor of the turbocharger. ### Claim 21 (depends on 15) The device of claim 15, wherein the laden exhaust-gas flow is supplied to the fresh-air side downstream of a compressor of the turbocharger. ### Claim 22 (depends on 15) The device of claim 15, wherein the laden exhaust-gas flow is supplied to the fresh-air side downstream of coolers installed in the fresh-air side. ### Claim 23 (depends on 13) The device of claim 13, wherein the flow rates of the exhaust-gas recirculation flow to the fresh-air side and of the aftertreatment partial flow to an exhaust-gas aftertreatment system are each regulated by at least one throttle device.