When stopping combustion in a cylinder under a situation in which the crankshaft of an internal combustion engine having an ignition device is rotating, a controller executes a fuel introduction process of injecting fuel from a fuel injection valve and introducing the fuel from inside the cylinder to the exhaust passage without burning the fuel. Also, the controller executes a storing process before starting the fuel introduction process. In the storing process, the controller stores oxygen in a three-way catalyst by executing a fuel cutoff process of stopping fuel injection of the fuel injection valve under a situation in which the crankshaft is rotating.

An engine exhaust device includes: a first catalyst; a second catalyst; a connection member and an exhaust gas outlet pipe. The first catalyst has a downstream end face and the second catalyst has an upstream end face. The downstream end face and the upstream end face form a predetermined dihedral angle. The upstream end face of the second catalyst and a side surface of the first catalyst closely face each other to form an overlap. A center axis of the exhaust gas outlet pipe is offset further toward the first catalyst than a center axis of the second catalyst is.

The present invention provides a catalyst diagnosis device that enables precisely grasping a variation of AFR and diagnosing a deteriorated condition of the catalyst based on the variation. A timer counts elapsed time Tosc until downstream AFU (AFRd) meets a predetermined threshold condition when the fuel injection quantity is corrected by increasing or decreasing it so that as to the AFRu, the transition from either of leanness or richness to the other is repeated with the stoichiometric area between the leanness and the richness. An OSA calculating section calculates an Oxygen Storage Amount (OSA) as a function of the AFR, Mfuel, Ne and Tosa. An OPA calculating section calculates an Oxygen Purge Amount (OPA) as a function of the AFR, Mfuel, Ne and Topa. A deterioration diagnosing section diagnoses a deteriorated condition of the catalyst C on the basis of at least one of the OSA and OPA.

Internal Combustion Engines, both Compression-Ignition (CI), mainly for Diesel oil, and Spark Ignition, for Gasoline, Compressed Natural Gas (CNG) or LPG emit pollutants during operation but particularly during cold startup in addition to nitrogen, carbon dioxide and water. The POLLUTANTS are: Carbon Monoxide (CO) Unburned Hydrocarbons (HC) and Nitrogen-Oxides (NOx) All cars today must be equipped with Catalytic Converters for oxidizing the CO to C02 and the HC to C02 and water and for the reduction of the NOx to N2 and water. These catalysts are inactive at temperatures below ca. 300 deg.c. and so when starting an engine from cold the emission of pollutants is high and not mitigated by the catalysts. Another problem is that a Reductant is required for the reduction of the NOx to N2 and water and the reductants in the exhaust gases namely CO and HC or Ammonia or Urea added to the flue gases are not efficient enough to fulfill the more stringent requirements for very low emission of NOx, There were many suggestions, in the literature and patents that propose the use of electrical heating of the catalysts monoliths, however the high burden on the batteries and also the long time needed for the heating made this approach virtually impractical. Another approach, for the DENOx and sometimes also for the cold startup was to manufacture hydrogen from water by electrolysis and first, store hydrogen and oxygen for injection into cold catalysts and ignite it prior to injection of the main fuel to the engine and secondly, during the run to produce hydrogen to be used as the reductant of NOx This approach also proved to be too difficult and costly and altogether impractical. In the present invention here an auxiliary small fuel system, preferably alcohol like Methanol, is installed. At cold startup the injection of the main fuel, such as Diesel Oil for CI engines or Gasoline for SI engines, is delayed for a few seconds and the compressed air from the engine flows into the after treatment main passage and mixes with injected Methanol and the mixture flows into the first catalyst section where at the inlet a metal net connected to an electrical source, such as a car battery, is heated igniting the mixture of air-methanol until the catalyst section is heated and then, in sequence, all catalyst sections, and in the case of a Diesel Engine also the DPF (DIESEL PARTICULATES FILTER), are heated up to the effective operating temperature. At that point all Methanol supply is cut off and a Methanol-Water mix is injected to a catalytic hydrogen production section (HPC) which is installed in parallel to the main exhaust passage and the Hydrogen rich stream is injected as the reda

A system of forcibly regenerating a gasoline particulate filter may include an exhaust pipe connected to the engine; a catalyst apparatus mounted on the exhaust pipe; first and second intake lines; first and second electric superchargers disposed on the first and second intake lines; a bypass line connecting a first point of the first supercharger and a second point of the second supercharger to each other; a first intake valve disposed at a downstream of the first point of the first intake line; a second intake valve disposed at an upstream of the second point of the second intake line; a bypass valve disposed on the bypass line; and a regeneration air line connecting the first intake line or the bypass line between the first electric supercharger, the first intake valve, and the bypass valve to the exhaust pipe between the catalyst apparatus and the gasoline particulate filter.

An improved catalytic converter includes a Coanda chamber assembly connected upstream of a catalytic reaction chamber, where the exhaust pipe is to be connected to the Coanda chamber assembly. The Coanda chamber assembly forms a Coanda chamber that has at least one narrower section and at least one wider section immediately downstream of the narrower section, with openings formed at the narrowest point of a narrower section. In operation, when engine exhaust gas is fed into the Coanda chamber, the gas pressure increases at the narrower section, and drops when the gas enters the wider section. As a result, air is sucked into the Coanda chamber via the openings and mixes with the exhaust gas. This lowers the exhaust temperature and enhances the efficiency of the catalytic reactions in the catalytic reaction chamber.

A catalytic reactor including: catalytic cassettes each including a catalyst part configured to reduce NOx in exhaust gas and an outer peripheral part made of a frame covering side surfaces of the catalyst part; and a lattice frame on which the catalytic cassettes are placed. The lattice frame includes a plurality of inflow holes through which exhaust gas flows into the catalyst parts and a plurality of frame parts which defines the respective plurality of inflow holes. The outer peripheral part of each of the catalytic cassettes is positioned so that the outer peripheral part is accommodated in a respective one of the frame parts.

An apparatus for reactivating a sulfur poisoned oxidation catalyst operating in the exhaust of a lean burn, methane source (as in natural gas) fueled combustion device as in an engine. The reactivation includes desulfation of the poisoned catalyst through the use of a CO supplementation apparatus in communication with the control unit that is adapted to supplement the CO content in the exhaust reaching the catalyst, while avoiding an overall rich exhaust atmosphere at the catalyst. An example includes the added supply of hydrocarbons to one or more, preferably less than all, of the lean burn engine's combustion chambers such as by an ECU controlled extra supply of NG (e.g., CNG) to some of the combustion chambers. Also featured is a method for desulfation of an oxidation catalyst of a lean burn CNG engine by supplying excess CO to the exhaust reaching the catalyst while retaining an overall lean state, and a method of assembling an apparatus for reactivating a sulfur deactivated lean burn NG engine catalyst by assembling a CO supplementation apparatus with a control unit.

The invention relates to an exhaust aftertreatment system for an internal combustion engine (10). The exhaust aftertreatment system comprises an exhaust system (20) having at least one three-way catalyst (22, 24) near the engine, wherein a particulate filter (28) is arranged downstream from the three-way catalyst, preferably in an underbody installation in a motor vehicle. A heated catalyst (26), which has at least one heating stage (62, 66, 68) that can be heated by means of an electric heating element (72, 74, 76, 78), is provided upstream from the at least one three-way catalyst (22, 24) and downstream from the particulate filter (28). It is provided that the at least one electrically heatable heating stage (62, 66, 68) is supplied with electric power directly from a generator (46) that is operatively connected to the internal combustion engine (10), so that heating of the heated catalyst (26) takes place essentially independently of the charge status of the vehicle battery (44). The invention also relates to a method for regeneration of a particulate filter (28) in the exhaust system (20) of an internal combustion engine (10) by means of such an exhaust aftertreatment system.

The invention relates to a method for exhaust gas aftertreatment in an internal combustion engine. For purposes of the exhaust gas aftertreatment in the internal combustion engine, an exhaust gas system is provided in which a first three-way catalytic converter is arranged, as seen in the direction in which the exhaust gas of the internal combustion engine flows through the exhaust gas system, while at least another three-way catalytic converter is arranged downstream from the first three-way catalytic converter. Here, at least one lambda probe is arranged in an exhaust gas channel of the exhaust gas system upstream from the appertaining three-way catalytic converters. In the proposed method, a component temperature of the three-way catalytic converters is determined and compared to a light-OFF temperature. In this process, the lambda control of the internal combustion engine is carried out by means of the lambda probe upstream from the last three-way catalytic converter that has reached its light-OFF temperature.

Moreover, according to the invention, an exhaust gas aftertreatment system for carrying out such a method is being proposed.