Hitachi, Ltd.

Other

Honda Motor Co., Ltd.

Toshifumi Hiratsuka

Osamu Kuroda

Yuichi Kitahara

Toshio Ogawa

Hisao Yamashita

Hidehiro Iizuka

Ryouta Doi

Kojiro Okude

Shigeru Azuhata

Norihiro Shinotsuka

Hiroshi Hanaoka

Toshio Manaka

Masato Kaneeda

Kousei Nagayama

Morio Fujitani

Takeshi Atago

Takeshi Inoue

Takao Ishikawa

Hiroatsu Tokuda

Hiroshi Tobita

Shinichi Ichikawa

Hidehiro Ilzuka

Hiroshi Kodairajousui Hausu 205 Hanaoka

An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which the exhaust gas containing NOx gas passes and a catalyst so disposed in the exhaust gas duct that it contacts with the exhaust gas. The catalyst chemically adsorbs NOx under the condition that a stoichiometric amount of a gaseous oxidizing agent present in the exhaust gas is larger than that of a gaseous reducing agent present in the exhaust gas for reducing NOx, while NOx being adsorbed is catalytically reduced in the presence of the reducing agent under the condition that the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent. Thereby, NOx, the lean burn exhaust gas in the engine can be effectively made harmlessly.

Exhaust gas purification apparatus of internal combustion engine and catalyst for purifying exhaust gas of internal combustion engine

Nitrogen oxides contained in an exhaust gas emitted from a lean-burn engine-mounted internal combustion engines are eliminated with a high efficiency. In an exhaust gas purification apparatus and process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Internal combustion engine exhaust gas purification apparatus, exhaust gas purification process and exhaust gas purification catalyst

A moisture removal device for an internal combustion engine use exhaust gas purifying device with a trapped moisture amount estimation means which estimates amount of moisture exhausted from an internal combustion engine and trapped in the catalyst, a judgement means which judges whether the estimated value of the trapped moisture amount exceeds a predetermined amount, and means for controlling removal of the moisture trapped in the catalyst, wherein when the estimated value of moisture trapped in the catalyst exceeds the predetermined value, a control of removing the moisture in the catalyst is performed. Whereby, since the moisture trapped by the catalyst can be removed and a possible elution of the catalyst components can be prevented, reduction of exhaust gas purifying performance of the catalyst can be prevented.

Moisture removal device and method thereof for internal combustion engine use exhaust gas cleaning device

In an exhaust gas purification process for eliminating nitrogen oxides contained in a combustion exhaust gas emitted from an internal combustion engine with a reducing gas such as carbon monoxide, hydrocarbons, etc. contained in the exhaust gas in the presence of a catalyst, a catalyst comprising all of Rh, Pt and Pd, at least one member selected from alkali metals and alkaline earth metals, and Mn or its compound, supported on a porous carrier is used.

Exhaust emission control process for internal combustion engines

An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which the exhaust gas containing NOx gas passes and a catalyst so disposed in the exhaust gas duct that it contacts with the exhaust gas. The catalyst chemically adsorbs NOx under the condition that a stoichiometric amount of a gaseous oxidizing agent present in the exhaust gas is larger than that of a gaseous reducing agent present in the exhaust gas for reducing NOx, while NOx being adsorbed is catalytically reduced in the presence of the reducing agent under the condition that the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent. Thereby, NOx the lean burn exhaust gas in the engine can be effectively made harmlessly.

An apparatus and method of highly efficiently purifying nitrogen oxides are provided. An NOx chemisorption reduction catalyst chemically absorbs NOx under a condition that an exhaust gas of an internal combustion engine is an oxidizing atmosphere and deoxidizes adsorbed NOx under a reducing atmosphere. An SOx absorbent absorbs SOx contained in the exhaust gas of the oxidizing atmosphere, and deoxidizes and release SOx absorbed in the reducing atmospheric exhaust gas. The catalyst and absorbent are arranged in the exhaust path to purify the exhaust gas while preventing or suppressing SOx-poisoning of the NOx chemisorption reduction catalyst.

Exhaust gas cleaning apparatus and method for internal combustion engine

Exhaust gas purification apparatus of internal combustion engine and

An exhaust gas purifying catalyst is provided for purifying NOx contained in an exhaust gas from an internal combustion engine of a vehicle operated at a high air fuel ratio due to excessive oxygen, using unburnt HC or CO in the exhaust gas as a reducing agent. The catalyst comprises platinum, strontium and a rare earth metal, as active components, each supported on a support of inorganic oxide. The active components of the catalyst include platinum of 0.01-3.7 by wt ratio, strontium of 0.01-55 by wt ratio and a rare earth metal of 0.01-36 wt ratio, per the inorganic oxide of 100 by wt ratio.

Exhaust gas purifying method and catalyst used therefor

In order to remove nitrogen oxide in an exhaust gas released from a lean burn engine, a catalyst: supporting an rare earth metal, an alkali earth metal, titanium, a noble metal, and magnesium on the surface of a porous carrier made of inorganic oxides is provided. In order to manufacture the catalyst, the rare earth metal is supported onto the surface of the carrier first, subsequently the alkali earth metal other than magnesium and titanium are supported, the noble metal is supported, and magnesium is supported finally onto the surface of the carrier. The catalyst of the present invention is scarcely poisoned by SOx in the exhaust gas released from the lean burn engine, and has a heat resistivity durable against high speed driving.

Method of manufacturing catalyst for cleaning exhaust gas released from

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Hitachinaka, Japan

Toshifumi Hiratsuka