Abstract: In an exhaust aftertreatment system comprising a NOx adsorber-catalyst followed by an SCR catalyst, means are provided for preventing the SCR catalyst from becoming heated to near the same peak temperatures as the NOx adsorber-catalyst during desulfation. In one embodiment, the means is a thermal mass between the NOx adsorber-catalyst and the SCR catalyst. In another embodiment, the means is a valve configured to selectively divert exhaust leaving the NOx adsorber-catalyst from the SCR catalyst. In a method of the invention, the NOx adsorber-catalyst temperature is cycled during desulfation. The peaks of the cycles are within an appropriate temperature range for desulfating the NOx adsorber-catalyst, but the average temperature is below the temperature range at which the SCR catalyst is damaged. The temperature peaks are damped as they travel from the NOx adsorber-catalyst to the SCR, whereby the SCR experiences much lower peak temperatures than the NOx adsorber-catalyst.

Abstract: An emission reduction apparatus includes first and second exhaust paths carrying respective first and second Nox traps. One trap has a smaller capacity than the other and is operative while the larger trap regenerates, allowing symmetric operation.

Abstract: A method of reducing exhaust emission from a catalytic converter apparatus of a vehicle, the apparatus including at least one catalytic converter, each of the at least one catalytic converter having a catalyst brick positioned within a predefined length of the vehicle. The method includes directing exhaust to pass more than once through the predefined length through at least one of the at least one catalyst brick. The converter apparatus can accelerate catalyst conversion reactions and thus accelerate converter system light-off.

Abstract: A particulate trap has a housing and a plurality of filters disposed within the housing. The particulate trap also has a plurality of dividers fluidly isolating one or more of the plurality of filters into filter divisions. The particulate trap has at least one inlet and at least one outlet individually associated with each filter division, and a valve assembly configured to selectively block a flow of exhaust air through each of the inlets.

Abstract: An exhaust gas system of a vehicular internal combustion engine comprises a plurality of exhaust gas catalytic converters having different working temperature ranges. Depending on the temperature of the exhaust gas the latter is directed to the one or those converters into whose working temperature range the exhaust gas temperature falls.

Abstract: A filter system includes a plurality of filter sections, each of the plurality of filter sections receiving a portion of flow. Each filter section includes a first filter, a second filter, an absorbing material disposed between the first and second filter, and at least one dispersion mechanism disposed between the first and second filter. The at least one dispersion mechanism assists in providing a fluid to the filter system.

Abstract: A particulate filter regenerating device is configured to regenerate a particulate filter that collects particulate from engine exhaust gas. The particulate filter regenerating device is configured to prevent the temperature of the particulate filter from exceeding an allowable temperature during regeneration when the quantity of accumulated particulate is estimated to be lower than it actually is due to variation of the estimate. When the amount of temperature rise per unit time of the particulate filter is larger than a prescribed value during regeneration, it is determined that the temperature of the particulate filter will soon exceed the allowable temperature and the temperature rise amount ?Texh of the exhaust gas is reduced (?Texh1 is the normal temperature rise amount). The larger the temperature rise per unit time is, the more the temperature rise amount of the exhaust gas is reduced.

Abstract: Various systems and methods are disclosed for carrying out combustion in a fuel-cut operation in some or all of the engine cylinders of a vehicle. Further, various subsystems are considered, such as fuel vapor purging, air-fuel ratio control, engine torque control, catalyst design, and exhaust system design.

Abstract: An exhaust system (1) is provided with an exhaust passage that allows exhaust gas discharged from an internal combustion engine to pass therethrough, an exhaust emission control unit including a catalyst (2,3) such as a three-way catalyst (27) to purify the exhaust gas, and an exhaust heat collecting unit that converts thermal energy of the exhaust gas into electric energy. The exhaust passage (25) is formed in the center of the exhaust system provided with the exhaust emission control unit. By-pass passages (26) are formed at both sides of the exhaust passage (25) through which the exhaust gas flows without passing through the exhaust emission control unit. The exhaust heat collecting unit (29) is provided on the outer side of each of the by-pass passages (26).

Abstract: The invention relates to systems for removing NOx from exhaust. In one aspect of the invention, after adsorption, an NOx adsorber is isolated from the main exhaust flow and desorption induced by raising the temperature. The desorbed NOx is combined with a reductant and reduced over a catalyst. Preferably, the reductant is syn gas produced in an on-board reformer. The catalyst need never be exposed to the main exhaust flow, which is particularly advantageous for catalysts sensitive to water, oxygen, or sulfur. In another aspect of the invention, a recirculating flow is induced through an NOx adsorber during a regeneration cycle. Recirculation can induce greater desorption at a given temperature, provide a source of heat for the adsorber, and allow a higher conversion rate with a fixed amount of catalyst. A further aspect of the invention relates to a vehicle-mounted adsorbers with provisions for heating.

Abstract: The present invention provides for an NOx adsorber aftertreatment system for internal combustion engines which utilizes a parallel arrangement of an adsorber catalyst and a bypass. The exhaust flow from the engine is routed through the adsorber during lean operation. At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that contains the adsorber catalyst to be regenerated (e.g., 20% through the catalyst leg, 80% of the flow to the bypass leg). A quantity of hydrocarbon is injected into the reduced-flow catalyst leg in order to make the mixture rich. Since the flow has been reduced in this leg, only a small fraction of the amount of hydrocarbon that would have been required to make the mixture rich during full flow is required. This will result in a substantial reduction in the fuel penalty incurred for regeneration of the adsorber catalyst.

Abstract: A cost-effective solution to remove particulates from diesel, especially light-duty diesel engines incorporates an oxidation catalyst (2) effective to convert NO in the exhaust from the engine to NO2 and a particulate trap (4) which traps no more than 85% by weight of the particulate, optionally by permitting gas to by-pass the trap.

Abstract: A variable flow regulator assembly includes a first stationary exhaust pipe, a second stationary exhaust pipe concentrically disposed within the first stationary exhaust pipe, and a movable exhaust pipe concentrically disposed between the first and second stationary exhaust pipes. The first stationary exhaust pipe includes one or more interference tabs concentrically and circumferentially fitted about its interior surface. The movable exhaust pipe includes one or more interference tabs concentrically and circumferentially fitted about its exterior surface. The interference tabs complimentarily interact and restrict the movement of the variable flow regulator so that the flow maldistribution of the exhaust gas stream entering the catalytic converter can be variably controlled.

Abstract: A vehicular atmosphere cleansing system utilizes a regenerative wheel having flow channels extending through the wheel coated with an adsorbant. An atmosphere stream passes through a first position dependent portion of the wheel where VOC's including HC's are adsorbed while a heated atmosphere stream passes through a second position dependent regenerative portion of the wheel whereat VOC's are desorbed. The adsorbant is activated carbon having particles of micropore size adhered to the substrate by a silicone binder producing high adsorption efficiencies while withstanding relatively high regenerative heat temperatures resulting from exhaust gas sensible heat. A hydrocarbon senses HC in the desorbed heated atmosphere stream to rotatively and sequentially index pie shaped, segmented portions of the wheel into the wheel's regenerative region while also functioning as the main component of an OBD device for the system.

Abstract: A system to supply hydrogen-rich fuel to an internal combustion engine, whereby a hydrogen-rich gas is produced from a liquid raw fuel by a hydrogen generator. The exhaust line of the internal combustion engine contains an exhaust purification system, such as a DeNOx catalytic converter, which is at least temporarily supplied with hydrogen-rich gas through a bypass line. In addition, the exhaust line is in thermal contact with the hydrogen generator in order to recover thermal energy.

Abstract: An exhaust gas purification apparatus for purifying exhaust gas exhausted from a diesel internal combustion engine and containing therein harmful substances including particulates, NOx, HC and CO, at least, comprises a removal part for trapping and removing particulates in the exhaust gas, a purification part for purifying NOx, HC and CO through contact, and a heat transfer part for transferring heat generated in the removal part to the purification part.

Abstract: A method for operating an internal combustion engine includes the step of measuring emission values of at least two pollutant components of an exhaust gas of an internal combustion engine. A value of at least one operating parameter of the internal combustion engine is changed in order to decrease an emission value of a first pollutant component if the emission value of the first pollutant component exceeds a given maximum threshold value. An emission value of a second pollutant component is monitored in order to determine whether the emission value of the second pollutant component remains below a maximum value for the second pollutant component and whether an increase in the emission value to the maximum value for the second pollutant component is permitted.

Abstract: An exhaust valve downstream of a diesel engine splits exhaust gasses between two catalysts. In one position, most of the exhaust gasses go to a first catalyst, and the remaining exhaust gasses, along with injected reductant go to a second catalyst. In a second position, most of the exhaust gasses go to the second catalyst, and the remaining exhaust gasses, along with injected reductant go to the first catalyst. In this way, a reduced cost system is achieved.

Abstract: A induction exhaust system, for an internal combustion engine, capable of the multi step processes of 1) scavenging the chamber of exhaust gases and free radicals, 2) breaking the scavenge vacuum wave behind each energetic exhaust pulse, releasing said free radicals and the overscavenged air fuel vacuumed from the intake manifold during valve overlap, and 3) induction of such free radicals, unburned fuel, and fresh matter including atmospheric air.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine is provided for switching a switching valve at an optimal timing in accordance with an actual activated state of a catalyzer and a heated state of an adsorbent to achieve an optimal exhaust gas characteristic. The exhaust gas purifying apparatus comprises a catalyzer disposed in an exhaust system of the internal combustion engine, an adsorbent filled in a second passage circumventing a first passage in the exhaust system for adsorbing hydrocarbons within exhaust gases, a switching valve operable to switch between an open position for opening the first passage and a close position for closing the first passage, an ECU for detecting an atmospheric pressure state, and a switching valve driver for driving the switching valve to the close position upon start of the internal combustion engine, and driving the switching valve to the open position in accordance with the detected atmospheric pressure state.

Abstract: Exhaust emission control apparatus and method for an internal combustion engine maintain a small amount of sulfur components contained in exhaust gas flowing out of a sulfur component retainer agent even if the amount of sulfur components retained by the agent becomes great. The exhaust emission control apparatus includes a NOx retainer agent and the sulfur component retainer agent. The apparatus performs a NOx releasing process of adjusting the air-fuel ratio of exhaust gas flowing into the sulfur component retainer agent so that the air-fuel ratio of exhaust gas flowing into the NOx retainer agent becomes substantially stoichiometric or rich of stoichiometry if NOx retained by the NOx retainer agent is to be released. The apparatus prohibits the air-fuel ratio of exhaust gas flowing into the sulfur component retainer agent from becoming substantially stoichiometric or rich of stoichiometry if the amount of the sulfur components retained by the agent is at least a first predetermined amount.

Abstract: A cost-effective solution to removing particulates from diesel, especially light-duty diesel engines incorporates an oxidation catalyst (2) effective to convert NO in the exhaust from the engine to NO2 and a particulate trap (4) which traps no more than 85% by weight of the particulate, optionally by permitting gas to by-pass the trap.

Abstract: An emission treatment system for a vehicle is provided that includes a plasma reactor is disposed in a main exhaust pipe and configured to reduce noxious emissions of an engine. A bypass pipe is connected to the main exhaust pipe both before and after the plasma reactor such that exhaust emissions can be caused to bypass the plasma reactor. A control valve is disposed at a position where the main exhaust pipe and the bypass pipe intersect, and is configured to selectively open and close the main exhaust pipe and the bypass pipe. A power supply unit supplies power to the plasma reactor and the control unit is coupled to the power supply unit and the control valve controlling a voltage of power supplied to the plasma reactor and an operation of the control valve.

Abstract: An apparatus, a system, and a method for treating exhaust gases from an internal combustion engine. The system and method employing the use of a catalytic device coaxial-arranged dual leg apparatus comprising a housing having a first flow path and a second flow path having coaxially arranged portions, a device for selectively directing the exhaust gases between the first flow path and the second flow path, and a first NOx adsorbing catalyst contained in the first flow path.

Abstract: An internal combustion engine emission control apparatus includes split passages that divide exhaust gas discharged from an internal combustion engine into a plurality of streams. Emission control catalysts are provided that individually divide the exhaust gas in the split passages, and remove a component present in the exhaust gas at a high removal rate if a temperature of exhaust gas that inflows via the split passages satisfies a predetermined temperature condition. A controller changes proportions of the amounts of flow of the exhaust gas into the split passages so that the predetermined temperature condition is satisfied in at least one split passage of the split passages. Therefore, the emission control can be performed in a broad range of changing temperatures of the exhaust gas.

Abstract: An exhaust emission control system for an internal combustion engine includes an exhaust passage that branches into a first exhaust branch passage and a second exhaust branch passage, which join at downstream ends thereof into a common exhaust passage, a NOx catalyst disposed in each of the exhaust branch passages, a particulate filter disposed in the common exhaust passage and located downstream of a joining point of the exhaust branch passages, and flow control valves that control the amounts of exhaust gas flowing through the respective exhaust branch passages.

Abstract: A device for purifying the exhaust gas of an internal combustion engine, which includes separate devices for purifying the particulates in the exhaust gas and a device for purifying NOx in the exhaust gas located integrally or separately in the exhaust system, is provided. At least two reducing material supply devices for supplying the reducing material to the device for purifying the particulates and the device for purifying NOx are arranged in the exhaust system. When the device for purifying the particulates or the device for purifying NOx requires a small amount of reducing material, one of the two reducing material supply devices supplies the required amount of reducing material to the exhaust system. When the device for purifying the particulates or the device for purifying NOx requires a large amount of reducing material, both of the two reducing material supply devices supply the required amount of reducing material to the exhaust system.

Abstract: An emissions control system is used with a compression ignition engine capable of producing an exhaust gas stream to be treated by a reduction agent which is mixed with the exhaust gas stream to convert the exhaust gas stream prior to being directed into an SCR catalyst capable of reducing NOx in the exhaust gas stream. An exhaust gas recirculation valve is associated with the compression ignition engine for directing the exhaust gas stream back into the compression ignition engine. An electronic control unit and sensors determine whether the temperature of the exhaust gas stream is at a predetermined temperature, and if so control operation of the valve to allow a portion of the exhaust gas stream to be directed into the SCR catalyst. A bypass valve may also be provided to prevent the exhaust gas stream from entering into the SCR catalyst.

Abstract: A diesel engine exhaust gas purifying device includes a first continuous regeneration type diesel particulate filter in the exhaust gas passage, a by-path by-passing a portion of the exhaust gas passage upstream of the first continuous regeneration type diesel particulate filter, a second continuous regeneration type diesel particulate filter in the by-path, a change-over valve in the exhaust gas passage between the ends of by-path, an exhaust gas temperature-elevating mechanism, an exhaust gas temperature region detecting mechanism, and a control mechanism for controlling the exhaust gas temperature-elevating mechanism and the change-over valve based on the exhaust gas temperature region.

Abstract: A method and a device for operating an internal combustion engine, in particular of a motor vehicle, which allow detecting a function of at least one actuating element in an exhaust branch without an additional sensory system. The internal combustion engine includes exhaust-gas recirculation via which exhaust gas is conveyed from the exhaust branch to an intake manifold in an activated state. The internal combustion engine includes at least one actuating element in the exhaust branch. In at least one operating state of the internal combustion engine, given activated exhaust-gas recirculation, a first intake-manifold pressure is ascertained in a first position of the at least one actuating element in the exhaust branch, and a second intake-manifold pressure in a second position of the at least one actuating element in the exhaust branch. The function of the at least one actuating element in the exhaust branch is monitored as a function of a difference between the first and the second intake-manifold pressures.

Abstract: An emission abatement assembly includes a pair of NOx traps arranged in a parallel arrangement. A fuel reformer generates a reductant fluid in the form of a reformate gas which is selectively supplied one of the traps during regeneration thereof. During regeneration of the trap, engine exhaust gas is directed through the other trap. A catalyzed soot filter is positioned downstream of the NOx traps. A method of operating an emission abatement assembly is also disclosed.

Abstract: A device for purifying the exhaust gas of an internal combustion engine includes a particulate filter carrying an active-oxygen releasing agent that can cause the sulfur poisoning, a SOx trap unit arranged upstream of the particulate filter, and a bypass section for making the exhaust gas mainly bypass said particulate filter when SOx is released from the SOx trap unit. Further, an exhaust choke valve for an exhaust brake is arranged between the SOx trap unit and the exhaust gas branch portion of the bypass section.

Abstract: An exhaust gas purification device having a NOx absorbent includes a by-pass passage for by-passing the NOx absorbent, an exhaust gas flow rate control portion for regulating both a flow rate of exhaust gas flowing to the NOx absorbent and the flow rate of the exhaust gas bypassing the NOx absorbent, and a reductant addition portion for adding reductant into an exhaust passage upstream of the NOx absorbent. In this device, when it is necessary to discharge sulfur components from the NOx absorbent, a temperature rise control is executed such that a temperature of the NOx absorbent becomes higher than a predetermined temperature. Next, a rich condition control is executed such that an air-fuel ratio of the exhaust gas flowing to the NOx absorbent becomes one of a substantially stoichiometric condition and a rich condition. The flow rate of the exhaust gas to the NOx absorbent during the temperature rise control is controlled so as to be higher than that during the rich condition control.

Abstract: A first exhaust emission purification device first and a second exhaust emission purification device, each have a continuously regenerating type DPF and an SCR catalyst to constitute exhaust emission purification system for a diesel engine. When the exhaust gas temperature is within a low-temperature region lower than a predetermined temperature region, the exhaust gas temperature is raised.

Abstract: An exhaust gas purification apparatus, for an engine having a combustion chamber, comprising an exhaust passage, a particulate filter arranged in the exhaust passage for removing particulate in exhaust gas exhausted from the combustion chamber by oxidation, and a device for controlling the characteristics of the exhaust gas flowing into the particulate filter, wherein, when the judging means judges that the particulate filter will be deteriorated by heat, the controlling device changes the characteristics of the exhaust gas flowing into the particulate filter to prevent the particulate filter from being deteriorated by heat.

Abstract: A process for operating an exhaust gas system comprises: producing an exhaust gas flow, introducing the exhaust gas flow to a system comprising a restricting device in fluid communication with an exhaust emission control device, and an exhaust conduit comprising an exhaust throttle device, restricting the flow of the exhaust gas stream to the restricting device, and discharging the exhaust gas stream from the restricting device into the exhaust emission control device. The flow is sufficiently restricted such that the exhaust gas stream discharged into the exhaust emission control device has a temperature perform a desired function selected from the group consisting of regeneration and light-off.

Abstract: The present invention provides for adsorber catalysts arranged in parallel. The exhaust flow from the engine is divided in a predetermined ratio between the two catalysts during lean operation (e.g. 50-50). At a predetermined regeneration time (for example, when the adsorber catalyst is 20% full), the exhaust gas flow is reduced through the parallel leg that is to be regenerated (e.g. 20-80). A quantity of hydrocarbon is injected into the reduced-flow leg in order to make the mixture rich. Once the leg has been regenerated, the flow distribution between the parallel legs is reversed, and the other catalyst leg is regenerated while the other side (which is now clean) receives the majority of the exhaust flow. Once both catalyst legs have been regenerated, the exhaust flow is adjusted back to normal (e.g. 50-50) until the catalysts are again ready for regeneration and reduction. A catalytic soot filter is positioned downstream from the adsorber.

Abstract: An exhaust aftertreatment system for use with an internal combustion engine includes at least one leg having a multi-stage NOx adsorber, with each NOx adsorber stage corresponding to a different temperature range of NOx adsorption. In a multi-pass aftertreatment system, a manifold has at least one inlet and a plurality of outlets. A plurality of legs are connected with a respective manifold outlet. Each leg has a NOx adsorber therein. At least one valve is positioned in association with at least one leg for at least partially opening and closing the at least one leg.

Abstract: An exhaust emission control system for an internal combustion engine has an exhaust passage switching device for switching an exhaust gas flow path, an HC adsorbent material disposed within the main exhaust passage for adsorbing and releasing unburned constituents in exhaust gases, and a control device for controlling the switching device such that the exhaust gas flow path is switched to the main exhaust passage when the unburned constituents is adsorbed by the HC adsorbent material, that the exhaust gas flow path is switched to the bypass exhaust passage when the unburned constituents adsorbed by the HC adsorbent material is released from the HC adsorbent material, and that the exhaust gas flow path is switched to the main exhaust passage when the release of the unburned constituents from the HC adsorbent material is completed.

Abstract: An exhaust gas purifying apparatus has a particulate filter, an oxidation catalyst, a front oxidation catalyst, a bypass path, and a passage switching device, in an exhaust gas path. The front oxidation catalyst is disposed further upstream than the oxidation catalyst. The bypass path bypasses the upstream side and the downstream side of the front oxidation catalyst. The passage switching device switches the flow of exhaust gas to the front oxidation catalyst side or the bypass path side. When the filter is forcibly recovered, the temperature of the exhaust gas is raised, and is made to pass through the front oxidation catalyst. After the oxidation catalyst is activated, the flow of the exhaust gas is switched by the passage switching device, and the exhaust gas is made to pass through the bypass path.

Abstract: An internal combustion engine of a motor vehicle has an adsorption catalyst which may be loaded with nitrogen oxides and unloaded. During the unloading, the exhaust-gas stream through the adsorption catalyst may be decreased by a control unit or an add-on device, using a valve. During the unloading, a fuel/air mixture may be added to the exhaust-gas stream reaching the adsorption catalyst, by the control unit or the add-on device, using an atomizer. Upon switching over from the unloading to the loading of the adsorption catalyst, the addition of the fuel/air mixture to the exhaust-gas stream is initially stopped by the control unit or the add-on device. The decreasing of the exhaust-gas stream is then ended after a predefined flushing time.

Abstract: A combustion chamber graphic analyzer (CCGA) computer software application has been developed for analyzing the performance of individual combustion chambers in an operating gas turbine. The CCGA identifies combustion chambers that are sustaining abnormally hot or cold combustion temperatures. The identification of hot or cold combustion chambers is graphically displayed by the CCGA on a computer display, printed report or other computer output. Whether a combustion chamber is operating hot or cold is determined based on a circumferential profile of the temperatures of the exhaust gases from the gas turbine. This circumferential temperature profile is rotated using a swirl angle to correlate the exhaust gas temperature profile with the circular array of combustion chambers.

Abstract: A method of operating a combustion apparatus such as an internal combustion engine is described, in which the apparatus includes at least one combustion chamber with an inlet port for primary combustion air, an apparatus to introduce into the combustion chamber primary fuel for combustion with the primary air, an exhaust port for combustion products, and an exhaust system for exhausting the combustion products to atmosphere, the method including introducing into the exhaust system secondary air, mechanically acting upon the secondary air and products of combustion in the exhaust system in the presence of a catalyst, to produce a reformed fuel, introducing the reformed fuel into the combustion chamber for combustion with primary fuel and primary air.

Abstract: An exhaust gas valve device in an internal combustion engine, including a first bearing member mounted between a valve shaft and a valve body with one end of the valve shaft turnably fitted into the first bearing member, a second bearing member mounted between the valve shaft and the valve body with the other end of the valve shaft turnably passed through the second bearing member, and an actuator connected to the other end of the valve shaft protruding from the second bearing member. The valve body, the valve shaft and the first and second bearing members are formed of metal materials having equivalent thermal expansion coefficients; the first and second bearing members are press-fitted into said valve body; and a skin of a graphite-based solid lubricant is formed on a surface of the valve shaft in regions corresponding to the first and second bearing members.

Abstract: An exhaust-heat recovery system comprises a catalytic converter, an exhaust heat exchanger, an air conditioner and an engine controller. The catalytic converter is such that exhaust discharged from an engine is passed therethrough and combustible components in the exhaust are burned through catalysis therein. The exhaust heat exchanger induces heat exchange between the exhaust having passed through the catalytic converter and a coolant having passed through the engine. The air conditioner generates a heating wind by means of the heat exchange between the coolant having passed through the exhaust heat exchanger and an air conditioning wind. The engine controller controls incrementally the combustible components in the exhaust to be burned in the catalytic converter when the prescribed condition for heating is not satisfied.

Abstract: An exhaust gas purification system of an internal combustion engine supplies hydrocarbon by performing a post injection and the like in order to combust particulate matters accumulated in a diesel particulate filter (a DPF) having an oxidation catalyst. An electronic control unit (an ECU) senses temperature of exhaust gas upstream of the DPF with an exhaust gas temperature sensor and determines an upper limit value of permissible quantity of the hydrocarbon supplied to the DPF based on the sensed temperature. The ECU controls post injection quantity so that the quantity of the actually supplied hydrocarbon does not exceed the upper limit value. Thus, hydrocarbon poisoning can be precluded, since the quantity of the actually supplied hydrocarbon does not exceed the upper limit value.

Abstract: This system for helping to regenerate a catalyzed particulate filter arranged in a motor vehicle diesel engine exhaust line, said filter (4) being positioned downstream of an oxidation catalyzt (3) on the output side of the engine (1), is characterized in that it has a gas bypass circuit (5) parallel to the terminals of the catalyzer (3) and fitted with means (6) for controlling the circulation of gases therein and in the catalyzer, in order, at the point when the regeneration of the particulate filter (4) is triggered, to divert a proportion of the gases laden with unburned hydrocarbons into the particulate filter (4) without passing via the catalyzer (3), so as to speed up the regeneration of the particulate filter.

Abstract: An emissions control system is used with a compression ignition engine capable of producing an exhaust gas stream to be treated by a reduction agent which is mixed with the exhaust gas stream to convert the exhaust gas stream prior to being directed into an SCR catalyst capable of reducing NOx in the exhaust gas stream. An exhaust gas recirculation valve is associated with the compression ignition engine for directing the exhaust gas stream back into the compression ignition engine. An electronic control unit and sensors determine whether the temperature of the exhaust gas stream is at a predetermined temperature, and if so control operation of the valve to allow a portion of the exhaust gas stream to be directed into the SCR catalyst. A bypass valve may also be provided to prevent the exhaust gas stream from entering into the SCR catalyst.

Abstract: Exhaust flow from an internal combustion engine is divided in a predetermined ratio between two adsorber catalysts arranged in parallel during lean operation. A regeneration cycle time is predetermined and regeneration is accomplished by injecting hydrocarbons into a catalyst leg having a reduced exhaust flow. Upon regeneration of the catalyst, the exhaust gas flow distribution is reversed and the opposite catalyst is regenerated while the regenerated catalyst bears the brunt of the exhaust flow. The exhaust flow then reverts to a normal (e.g. 50—50) flow distribution until another regeneration cycle is warranted. A catalytic soot filter placed upstream of each adsorber is also regenerated by hydrocarbon injection. The addition of the catalytic soot filter provides more time and surface area for the hydrocarbon to react with the oxygen. Some of the diesel fuel is reformulated into hydrogen and carbon monoxide for superior regeneration.

Abstract: A device for purifying exhaust gas of a diesel engine includes a first continuous regeneration type diesel particulate filter (DPF) disposed in the exhaust gas passage of the engine, a second continuous regeneration type DPF having a capacity smaller than the capacity of the first continuous regeneration type DPF and disposed in the exhaust gas passage on the upstream side of the first continuous regeneration type DPF, a by-path surrounding the outer peripheral portion of the second continuous regeneration type DPF, a control valve for opening and closing the by-path, an exhaust gas temperature region-detector for detecting the exhaust gas temperature region of the engine, and a controller for controlling the control valve so as to close the by-path when the exhaust gas temperature region of the engine is in a low temperature region, lower than a predetermined temperature.