A vehicle exhaust gas reduction system positioned in an exhaust system of an engine includes: an electrically heated catalyst (EHC) of heating exhaust gas of the engine by electrically generating heat; a sub-gasoline particulate filter (Sub GPF) heated by operation of the EHC to combust a particulate number (PN) included in the exhaust gas; a main gasoline particulate filter (Main GPF) of purifying the exhaust gas discharged from the engine; and a controller configured for performing PN reduction control by operating the EHC to be On in a low-temperature condition, and increasing a temperature of the Sub GPF to a reference temperature at which soot combustion is possible, combusting the PN passing through the Sub GPF and soot collected in the Sub GPF.

Vehicle exhaust system uses delta pressure based estimation of accumulated soot within a diesel particulate filter. The exhaust system has a diesel oxidation catalyst and a diesel particulate filter. A fuel injector is connected upstream from the diesel oxidation catalyst and the diesel particulate filter. A delta pressure sensor measures difference in pressure at inlet and outlet of the diesel particulate filter. A controller determines when to regenerate the diesel particulate filter based on an estimated amount of soot. The controller, in a first regeneration mode, causes the fuel injector to inject fuel at a first rate into the exhaust stream, and to re-evaluate amount of soot accumulated within the diesel particulate filter under increased volumetric flow. The controller, in a second regeneration mode, causes the fuel injector to inject fuel at a second rate into the exhaust stream in order to combust soot trapped in the diesel particulate filter.

Methods and systems are provided for an aftertreatment system. In one example, a method comprises regenerating a NO.sub.x trap during an engine shut-down event. The method further comprises reversing a direction of flow of a gas through a HP-EGR passage during the regenerating.

Methods and systems are provided for regenerating and purging a particulate filter of an exhaust treatment system for a combustion engine. In one example, a method may include flowing exhaust gas in a reverse direction through the particulate filter to purge particulate matter to an intake manifold of the engine for combusting. The duration of purging may be based on a regeneration achieved during a previous regeneration of the particulate filter during a deceleration fuel shut-off event.

A vehicle includes a filter, a negative-pressure mechanism, and a first opening and closing mechanism. The filter is disposed in an exhaust passage coupled to an engine. The negative-pressure mechanism is configured to pressurize a portion of the exhaust passage upstream of the filter to a negative pressure less than an atmospheric pressure. The first opening and closing mechanism includes an opening disposed in the exhaust passage, and a valve configured to selectively open and close the opening. The valve is configured to, when the exhaust passage becomes negatively pressurized by the negative-pressure mechanism, open the opening.

The present invention generally relates to a process and apparatus for cleaning and removing particulate deposits in a particulate filter, in particular for the dry removal of ash deposits with a diesel particulate filter. Compared to the art known procedures, the method of the present invention is based on the provision of a two-stage process including a stage wherein the filter is exposed to a structural resonant frequency under pressure and a stage wherein the filter is exposed to a reverse flow. Combination of a structural resonance frequency with a reverse flow results in an efficient two-stage removal of the debris from the filter without causing any damage to the ceramic body of the filter.

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.

The present disclosure provides an exhaust gas purification apparatus for motor vehicles that has succeeded in suppressing peeling of a coat layer from an exhaust gas purification catalyst. Such exhaust gas purification apparatus for motor vehicles comprises: an exhaust gas purification catalyst comprising a substrate and a coat layer coated on the substrate comprising a microwave-absorbing material, a noble metal, and aluminum oxide (Al.sub.2O.sub.3); and a microwave-generating apparatus for heating the microwave-absorbing material located ahead of the exhaust gas purification catalyst with respect to an exhaust gas flow direction, wherein the microwave-absorbing material includes NiFe.sub.2O.sub.4, the noble metal includes at least one metal selected from the group consisting of platinum (Pt), palladium (Pd), and rhodium (Rh), and contents of zinc oxide (ZnO) and copper(II) oxide (CuO) in the coat layer are equivalent to or lower than the given levels.

A method of removing impurities from a gas including the steps of removing impurities from biogas comprising at least one adsorbents via a process vessel or reactor, directing the purified gas to an device to generate power and/or heat, regenerating the saturated adsorption media with the waste heat recovered from the engine exhaust and directing the regeneration gas (hot air or engine exhaust) to flare, engine exhaust stack, or atmosphere.

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.