Abstract: A method of and apparatus for purifying an exhaust gas of an internal combustion engine comprising an NOx purifying catalyst arranged in an exhaust gas passage, wherein the NOx purifying catalyst is made of a composite material containing at least one kind of element selected from alkaline metals and alkaline earth metals, at least one kind of element selected from rare earth metals, at least one kind of element selected from platinoid metals, and titanium (Ti), the NOx purifying catalyst adsorbing NOx in the exhaust gas onto the surface when the exhaust gas is lean, and reducing the adsorbed NOx to N2 when the exhaust gas is stoichiometric or rich, and wherein the exhaust gas is purified by adsorbing NOx in the exhaust gas in the NOx purifying catalyst when the internal combustion engine is being operated under a lean condition, and by setting, after the adsorption, the exhaust gas to a stochiometric state or a rich state for 0.5 second to 4.

Abstract: 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.

Abstract: A gas stream containing at least one fluorine compound selected from the group consisting of compounds of carbon and fluorine, compounds of carbon, hydrogen and fluorine, compounds of sulfur and fluorine, compounds of nitrogen and fluorine and compounds of carbon, hydrogen, oxygen and fluorine is contacted with a catalyst comprising at least one of alumina, titania, zirconia and silica, preferably a catalyst comprising alumina and at least one of nickel oxide, zinc oxide and titania in the presence of steam, thereby hydrolyzing the fluorine compound at a relatively low temperature, e.g. 200°-800° C., to convert the fluorine of the fluorine compound to hydrogen fluoride.

Abstract: An exhaust gas purification apparatus for use in an internal combustion engine comprises an exhaust gas duct connected to the engine through which exhaust gas containing NO.sub.x gas passes, and a catalyst disposed in the exhaust gas duct such that it contacts the exhaust gas. The catalyst chemically adsorbs NO.sub.x when 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 NO.sub.x, adsorbed NO.sub.x is catalytically reduced in the presence of a reducing agent when the stoichiometric amount of the oxidizing agent is not larger that of the reducing agent.

Abstract: A treating apparatus for decomposing organohalogen compounds such as chlorofluorocarbons (CFC's), trichloroethylene, methylbromide, halon, and the like, effectively, with a high activity of catalyst, is provided. The apparatus includes a reactor in which organohalogen compounds are decomposed by contact at a temperature in a range of 200.degree..about.500.degree. C. with a catalyst which comprises titania and tungsten oxide by an atomic ratio of Ti and W in a range from 20 mol % to 95 mol % Ti and from 5 mol % to 80 mol % W, with at least the surface of the titania being covered with a porous layer of the tungsten oxide. In accordance with the present invention, organic compounds containing any of fluorine, chlorine and bromine will be decomposed with a high efficiency, and the activity of the catalyst can be maintained for a long time.

Abstract: 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.

Abstract: 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.

Abstract: A catalyst being formed of a porous supporter supporting alkali metals, Ti and a noble metal, or further supporting at least one of rare earth metal and magnesium, being disposed in a flow passage of an internal combustion engine, and being used to purify NOx contained in the exhaust gas. The above catalyst has NOx resistance to exhaust gas burnt with a rich condition and with a lean condition and a high resistivity to poisoning by SOx.

Abstract: A method for treating a gas flow containing organohalogen compounds including the steps of contacting the gas flow with a catalyst at a temperature below 500.degree. C. in the presence of an effective amount of steam, wherein the catalyst contains titania, tungsten oxide, and silica, the Ti and W are present in the range of 20-95 mol % Ti and 5-80 mol % W based on Ti and W, and the amount of silica is in the range of 0.5-15% by weight silica to 100% by weight titania. Accordingly, the organohalogen compound can be decomposed effectively to carbon monoxide, carbon dioxide, and hydrogen halide.

Abstract: A treating method for decomposing organohalogen compounds such as chlorofluorocarbons (CFC), trichloroethylene, methyl bromide, halon, and the like, effectively, with a high activity of catalyst is provided.Organohalogen compounds are decomposed by contacting at a temperature in a range of 200.degree..about.500.degree. C. with catalyst which comprises titania and tungsten oxide by an atomic ratio of Ti and W in a range from 20 mol % to 95 mol % Ti and from 5 mol % to 80 mol % W, and at least surface of the titania is covered with porous layer of tungsten oxide.In accordance with the present invention, organic compounds containing any of fluorine, chlorine, and bromine can be decomposed with a high efficiency, and the activity of the catalyst can be maintained for a long time.

Abstract: An apparatus for purifying an exhaust gas emitted from an internal combustion engine, particularly, immediately after starting of the engine, includes a mechanism for reducing the time required to heat a catalyst converter to the activation temperature. The exhaust gas is passed through a preliminary catalyst close to the engine and then through a main catalyst downstream of the catalyst. The engine is operated with an air-fuel mixture which is richer than the amount indicated by the stoichiometric air/fuel ratio for a period of time from when engine is started until the main catalyst is heated to a temperature at which the catalyst can sufficiently perform its purifying capability. The preliminary catalyst is enabled to function at lower temperatures by combusting the exhaust gas which is generated during a rich air-fuel mixture condition. The main catalyst can be heated with the generated combustion heat, resulting in an enhancement in exhaust gas purifying capability.

Abstract: The present invention provides a method for producing a synthetic diamond thin film which comprises decomposing with microwave a raw material gas containing at least one compound selected from the group consisting of carbon monoxide, carbon dioxide and a hydrocarbon and hydrogen or hydrogen and oxygen to produce a plasma and contacting the plasma with the surface of a substrate held outside the area irradiated with the microwave to form a diamond thin film on the substrate.The present invention further provides an apparatus for producing a synthetic diamond thin film and a synthetic diamond thin film and devices in which the synthetic diamond thin film is used.

Abstract: An exhaust gas cleaning system has a catalyzer provided in the exhaust passage of the engine and an adsorbent provided upstream from the catalyzer. The adsorbent temporarily adsorbs unburned hydrocarbons emitted in large amounts immediately after the engine is started. The system provides an amount of air required to substantially eliminate unburned hydrocarbons, based on the temperature of the adsorbent and the oxygen concentration in exhaust gas upstream from the catalyzer. An air supplying unit is provided upstream from the adsorbent. A temperature sensor is provided for the adsorbent. An oxygen sensor is provided at the inlet of the catalyzer. A control unit calculates the amount of air (oxygen) necessary for the catalyzer to convert the unburned hydrocarbons released from the adsorbent, based on signals from the temperature sensor and the oxygen sensor and the exhaust flow rate. The control unit accordingly controls the air supplying unit.

Abstract: The present invention provides a poisoning-resistant catalyst for combustion of CO and inflammable gases which comprises an inorganic carrier, a noble metal active ingredient supported on said inorganic carrier, and silica supported on said noble metal active ingredient, said noble metal active ingredient comprising at least one member selected from the group consisting of Pt, Rh and Pd, the surface of said catalyst being richer in silica and the inner part of said catalyst becoming richer in said noble metal active ingredient the deeper from the surface said inner part becomes; and a catalytic combustion apparatus for burning inflammable gases in a starting gas by the use of said catalyst. Said catalyst has a high resistance to poisoning and has a high level of activity at a low temperature of 200.degree. C. or lower.

Abstract: A method for growing a thin film on a substrate of metal or ceramics by beam deposition comprising the steps of:(I) producing from starting gases ions of elements or compounds thereof to be deposited on the substrate;(II) irradiating the ions produced in step (I) with electromagneti waves to electronically excite at least one sort of said ions; and(III) impacting an ion beam comprising the ions excited in step (II) onto said substrate to deposit thereon, thereby growing a film, and an apparatus for practicing the method. The method enables the formation of thin films having a higher crystallinity by electronically exciting ions or neutral species to increase the internal energy thereof and then impacting a beam comprising the excited ions or neutral species onto the substrate.

Abstract: A process for removing nitrogen oxides from exhaust gases containing volatile metal compounds with good efficiency by contacting the gases with a catalyst comprising TiO.sub.2, difficulty reduced by the compounds, in the presence of ammonia, and such a catalyst are provided, which process is characterized in that the average pore diameter of the TiO.sub.2 is 10,000 .ANG. or less and the proportion of the volume of pores having pore diameters of 400-5,000 .ANG. to the total pore volume is 50% or more; a denitration-active component is supported on the TiO.sub.2 ; a catalyst carrier precursor comprising an aqueous slurry sol of TiO.sub.2 or Ti hydroxide prepared by hydrolyzing a Ti salt is precalcined at 150.degree.-700.degree. C., followed by adding a denitration-active component and then normally calcining the mixture; and a polymer compound having a thermal decomposition temperature of 110.degree. to 300.degree. C.

Abstract: A process for removing nitrogen oxides from exhaust gases containing volatile metal compound by the use of a catalyst the activity of which is hardly reduced by the volatile metal compound and a catalyst for the process are provided, which process comprises contacting the exhaust gases with a catalyst comprising TiO.sub.2 and a composite oxide of vanadium and molybdenum and/or a composite oxide of vanadium and manganese in the presence of ammonia.

Abstract: The disclosure is concerned with a high temperature stable catalyst comprising an alumina base support and a catalytically active component supported on the support. The support is featured by its specific composite oxide having a specific surface area of at least 10 m.sup.2 /g and a structural form of amorphous state or a phase resemble to lanthanoide .beta.-alumina. The composite oxide can be converted to lanthanoide .beta.-alumina when heated to an elevated temperature above 1000.degree. C. within 2 hours. The composite oxide is substantially free from such ingredients as accelerate grain growth of alumina. The ingredients are for example Cr, Sr or Ce.The present dislcosure is also concerned with a process for preparing the catalyst and a process for conducting chemical reactions such as steam reforming, desulfurization of heavy oil, cracking of hydrocarbons, etc. using the catalyst.

Abstract: The present invention provides a desulfurizing agent comprising a porous oxide carrier, at least one of molybdenum oxide and tungsten oxide as a first component, supported on the carrier, and at least one of manganese oxide, cobalt oxide and nickel oxide as a second component, supported mainly on the surface of the first component. In a coal gasification system using the present desulfurizing agent and a power generation system using the purified gas therefrom, a reduction column for converting a portion of sulfur dioxide in the regenerated gas to hydrogen sulfide as a pretreatment means to a Claus reaction column can be eliminated when the desulfurizing agent is regenerated.

Abstract: A process for removing nitrogen oxides from exhaust gases containing at least nitrogen oxides and volatile metal compounds by the use of a catalyst having prevented activity reduction due to the volatile metal compounds and having a superior durability is provided, which process comprises contacting the exhaust gases with a catalyst containing TiO.sub.2, a compound active to nitrogen oxides-removing reaction such as oxides of V, Cr, Mo, W, Fe, Co, Ni, Cu, Ce, etc. and/or sulfates thereof and a metal sulfate containing water of crystallization such as those of Al, Mg or Mn, in the presence of ammonia at 150.degree. to 600.degree. C.