# US 11,898,483 B2 · Systems and methods for operating passive nitrogen oxide adsorbers in exhaust aftertreatment systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,898,483 B2 - Document ID: US11898483B2 - Status: Granted - Kind: B2 - Application number: 17/748,559 - Filed: 2022-05-19 - Published: 2022-09-01 - Granted: 2024-02-13 - Earliest claimed: 2019-11-21 - Assignees: Cummins Inc. - Applicants: Cummins Inc. - Inventors: Jinyong Luo; Xiaobo Song; Xing Jin; David Schmidt; Lu Qiu; Lisa A. Orth-Farrell; Ying Yuan; Manik Narula; Lars K. Henrichsen - Web page: https://patentgrep.com/patent/US11898483B2 ## CPC - F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts} - F01N 3/2892: {Exhaust flow directors or the like, e.g. upstream of catalytic device} - B01D 53/02: by adsorption, e.g. preparative gas chromatography {(solid sorbent compositions B01J20/00, preparation of inorganic compounds or elements C01)} - B01D 53/9418: {for removing nitrogen oxides by selective catalytic reduction [SCR] using a reducing agent in a lean exhaust gas} - B01D 53/9431: {Processes characterised by a specific device} - B01D 53/9481: {Catalyst preceded by an adsorption device without catalytic function for temporary storage of contaminants, e.g. during cold start} - B01D 53/9495: {Controlling the catalytic process} - F01N 3/0842: {Nitrogen oxides} - F01N 3/2066: {Selective catalytic reduction [SCR]} - F01N 3/2803: {characterised by structure, by material or by manufacturing of catalyst support} - 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 - F02D 29/06: peculiar to engines driving electric generators - B01D 53/9422: {for removing nitrogen oxides by NOx storage or reduction by cyclic switching between lean and rich exhaust gases (LNT, NSC, NSR)} - B01D 2251/2062: Ammonia - B01D 2251/2067: Urea - B01D 2253/108: Zeolites - B01D 2253/112: Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106 - B01D 2253/1124: Metal oxides - B01D 2255/1021: Platinum - B01D 2255/1023: Palladium - B01D 2255/104: Silver - B01D 2255/2065: Cerium - B01D 2255/50: Zeolites - B01D 2255/91: NOx-storage component incorporated in the catalyst - B01D 2257/404: Nitrogen oxides other than dinitrogen oxide - B01D 2259/4566: for use in transportation means - F01N 2370/04: Zeolitic material - F01N 2410/04: during regeneration period, e.g. of particle filter - F01N 2550/03: of sorbing activity of adsorbents or absorbents - F01N 2560/06: the means being a temperature sensor - F01N 2590/11: for hybrid vehicles - F01N 2900/10: said parameters being related to the vehicle or its components - F01N 2900/1602: Temperature of exhaust gas apparatus - F01N 2900/1621: Catalyst conversion efficiency - Y02C 20/10: of nitrous oxide (N2O) - 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) - F02D: CONTROLLING COMBUSTION ENGINES (vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed B60K31/00; conjoint control of vehicle sub-units of different type or different function, road vehicle drive control systems for purposes other than the control of a single sub-unit B60W) - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract A system includes a catalyst for receiving and treating exhaust gas generated by an engine, a passive NOx adsorber (PNA) positioned upstream of the catalyst, a bypass valve positioned upstream of the catalyst and the PNA, and a controller. The controller is configured to, determine that the catalyst is operating under cold start conditions, control the bypass valve to direct exhaust gas to the PNA, determine that the catalyst is no longer operating under cold start conditions and continue to control the bypass valve to direct exhaust gas to the PNA for a predetermined duration, and after the elapse of the predetermined duration, control the bypass valve to direct exhaust gas to the catalyst bypassing the PNA. The controller is also configured to detect a high transient torque demand while the exhaust gas is provided to the PNA, and split the torque demand between the engine and an electric motor. ## Claims ### Claim 1 A system, comprising: a catalyst for receiving and treating exhaust gas generated by an engine; a passive NOx adsorber (PNA) positioned upstream of the catalyst and fluidly coupled with the catalyst; a bypass valve positioned upstream of the catalyst and the PNA; and a controller configured to: determine that an effectiveness of the catalyst in reducing NOx is below a threshold level, in response to determining that the effectiveness of the catalyst in reducing NOx is below the threshold level, control the bypass valve to direct exhaust gas to the PNA, subsequent to controlling the bypass valve to direct exhaust gas to the PNA, determine that the effectiveness of the catalyst is no longer below the threshold level, and in response to determining that the effectiveness of the catalyst is no longer below the threshold level: continue to control the bypass valve to direct exhaust gas to the PNA for a predetermined duration and increase a load on the engine by mechanically engaging a generator with the engine, and utilize resulting electrical energy generated by the generator to charge a battery system; and after PNA regeneration conditions are met upon an elapse of the predetermined duration, control the bypass valve to direct exhaust gas to the catalyst bypassing the PNA. ### Claim 2 (depends on 1) The system of claim 1, wherein the effectiveness of the catalyst is determined to be below the threshold level based on a determination that a temperature of the catalyst is below a first threshold value. ### Claim 3 (depends on 1) The system of claim 1, wherein the effectiveness of the catalyst is determined to be below the threshold level based on a determination that NOx at the output of the catalyst is below a first threshold value. ### Claim 4 (depends on 1) The system of claim 1, wherein the PNA regeneration conditions are met upon a combination of the elapse of the predetermined duration for which exhaust gas is directed through the PNA and an indication of exhaust gas temperature. ### Claim 5 (depends on 1) The system of claim 1, wherein the controller is further configured to adjust the bypass valve such that exhaust gas received at an input port is proportionally output between a PNA conduit and a bypass conduit. ### Claim 6 (depends on 1) The system of claim 1, wherein the controller is further configured to adjust the bypass valve such that the exhaust gas received at an input port is output only to a PNA conduit and not a bypass circuit. ### Claim 7 (depends on 1) The system of claim 1, wherein the PNA comprises NOx adsorbing elements including at least one of palladium, platinum, sliver, zeolite, Al2O3, and CeO2-containing materials. ### Claim 8 A method for operating passive nitrogen oxide adsorbers (PNA) in an exhaust aftertreatment system, the method comprising: determining that an effectiveness of a catalyst in reducing NOx is below a threshold level, the catalyst for receiving and treating exhaust gas generated by an engine; in response to determining that the effectiveness of the catalyst in reducing NOx is below the threshold level, controlling a bypass valve to direct exhaust gas to the PNA, the PNA positioned upstream of the catalyst and fluidly coupled with the catalyst and the bypass valve positioned upstream of the catalyst and the PNA; subsequent to controlling the bypass valve to direct exhaust gas to the PNA, determining that the effectiveness of the catalyst is no longer below the threshold level; and in response to determining that the effectiveness of the catalyst is no longer below the threshold level: continuing to control the bypass valve to direct exhaust gas to the PNA; while continuing to control the bypass valve to direct exhaust gas to the PNA, increasing a load on the engine, wherein the load on the engine is increased by mechanically engaging a generator with the engine and utilizing resulting electrical energy generated by the generator to charge a battery system; and after PNA regeneration conditions are met, controlling the bypass valve to direct exhaust gas to the catalyst bypassing the PNA. ### Claim 9 (depends on 8) The method of claim 8, wherein the effectiveness of the catalyst is determined to be below the threshold level based on a determination that a temperature of the catalyst is below a first threshold value. ### Claim 10 (depends on 8) The method of claim 8, wherein the PNA regeneration conditions are met upon an elapse of a predetermined duration for which exhaust gas is directed through the PNA after determining that the effectiveness of the catalyst is no longer below the threshold level. ### Claim 11 (depends on 8) The method of claim 8, further comprising: while controlling the bypass valve to direct exhaust gas to the PNA, detecting a torque demand of the engine that is greater than a threshold value; responsive to detecting that the torque demand is greater than the threshold value, engaging a motor coupled with the battery system with a drive shaft of the system to meet at least a portion of the torque demand; and in response to the engagement of the motor with the drive shaft not meeting all of the torque demand, engaging the engine with the drive shaft to meet a remainder of the torque demand. ### Claim 12 (depends on 11) The method of claim 11, wherein the engine is engaged with the drive shaft in response to determining that the motor has reached its maximum torque capacity, but that the torque demand has not been met.