The present disclosure encompasses methods and systems for decontaminating polluted gas using heated volcanic rock.

The present invention relates to a method for cleaning exhaust gas, and a correspondingly designed exhaust gas system. The present method, or the corresponding system, serves to avoid the formation of nitrous oxide as a secondary exhaust gas, which may primarily be created during the loading of specific catalyst types with NH.sub.3.

An overall exhaust gas purification function based on an NOx reduction function and an HC oxidation function in an NSR catalyst arranged in an exhaust passage of an internal combustion engine is improved. In the NSR catalyst, a portion of an NOx storage catalyst layer supported by a carrier, which extends from its upstream end to an X % (0<X≦75) of an overall length thereof along the flow of exhaust gas, forms an upstream side catalyst layer, and a portion of the NOx storage catalyst layer at the downward side of the upstream side catalyst layer along the flow of exhaust gas forms a downstream side catalyst layer. The upstream side catalyst layer does not contain potassium (K) as an NOx storage material, but the downstream side catalyst layer contains potassium (K) as an NOx storage material.

An emission control system includes an emission control device having a plurality of passages to facilitate emission control of an exhaust gas from a vehicle engine. An electromagnetic field generator responds to a control signal by generating an electromagnetic field via a coil to inductively to heat the emission control device, A controller, coupled to the electromagnetic field generator, generates a temperature signal indicating at least one temperature of the emission control device based on a change in impedance in the coil and generates the control signal based on the temperature signal and further based on a reference temperature to control the at least one temperature of the emission control device in accordance with the reference temperature.

An exhaust system includes at least one exhaust gas purification component, at least one exhaust line, at least one connecting device for connecting the exhaust system to an internal combustion engine of a motor vehicle and at least one fastening element for additionally fastening the exhaust system to the motor vehicle. The purification component can oscillate at a first resonance frequency range of less than 150 Hz in a fastened state. The purification component can oscillate due to vibrations of the engine at least when the engine is started or switched off. This, in particular, allows ash residues to be removed from a purification component during starting of the motor vehicle, so that maintenance expense for the purification component is reduced and effective operation thereof is possible over the long term. A motor vehicle having an exhaust system and a method for operating the motor vehicle are also provided.

An exhaust system includes at least one exhaust gas purification component, at least one exhaust line, at least one connecting device for connecting the exhaust system to an internal combustion engine of a motor vehicle and at least one fastening element for additionally fastening the exhaust system to the motor vehicle. The purification component can oscillate at a first resonance frequency range of less than 150 Hz in a fastened state. The purification component can oscillate due to vibrations of the engine at least when the engine is started or switched off. This, in particular, allows ash residues to be removed from a purification component during starting of the motor vehicle, so that maintenance expense for the purification component is reduced and effective operation thereof is possible over the long term. A motor vehicle having an exhaust system and a method for operating the motor vehicle are also provided.

A chemical heat storage device includes a reactor disposed around an oxidizing catalyst and containing MgCl.sub.2 which chemically reacts with NH.sub.3 to generate heat, a storage connected to the reactor through a pipe to store NH.sub.3, an on-off valve disposed in the pipe, a temperature sensor detecting the temperature of the exhaust gas passing through the oxidizing catalyst, and a controller controlling the on-off valve based on the detected value of the temperature sensor. The controller controls the on-off valve such that the on-off valve unconditionally opens if the temperature of the exhaust gas is greater than a heat generating start temperature T.sub.L and is equal to or less than a heat generating end guide temperature T.sub.Q, and the on-off valve unconditionally opens if the temperature of the exhaust gas is greater than a regenerating temperature T.sub.H.

The invention relates to a catalyst system for reducing nitrogen oxides, which comprises a nitrogen oxide storage catalyst and an SCR catalyst, wherein the nitrogen oxide storage catalyst consists of at least two catalytically active washcoat layers on a supporting body, wherein a lower washcoat layer A contains cerium oxide, an alkaline earth compound and/or alkali compound, as well as platinum and palladium, and an upper washcoat layer B, which is arranged over the washcoat layer A, contains cerium oxide, platinum and palladium, and no alkali compound and no alkaline earth compound. The invention also relates to a method for converting NOx in exhaust gases of motor vehicles that are operated by means of engines that are operated in a lean manner.

Provided are a novel synthesis technique for producing pure phase aluminosilicate zeolite and a catalyst comprising the phase pure zeolite in combination with a metal, and methods of using the same. The pure phase aluminosilicate zeolite can be selected from those having an ITW framework and a silica to alumina ratio of less than about 140 or, an STW framework and a silica to alumina ratio less than about 100.

The internal combustion engine comprises an exhaust purification catalyst able to store oxygen, and a downstream side air-fuel ratio sensor arranged at a downstream side of the exhaust purification catalyst in a direction of exhaust flow. The control system performs feedback control of an amount of fuel fed to a combustion chamber of the internal combustion engine so that an air-fuel ratio of exhaust gas flowing into the exhaust purification catalyst becomes a target air-fuel ratio and performs learning control to correct a parameter relating to the feedback control based on an air-fuel ratio of exhaust gas detected by the downstream side air-fuel ratio sensor. The target air-fuel ratio is alternately switched between a rich set air-fuel ratio and a lean set air-fuel ratio leaner. When a condition for learning acceleration, which is satisfied when it is necessary to accelerate correction of the parameter by the learning control, is satisfied, a rich degree of the rich set air-fuel ratio is increased. Therefore, there is provided an internal combustion engine able to suitably change the speed of updating the learning value.