Hitachi, Ltd.

Babcock-hitachi Kabushiki Kaisha

Hiroshi Kawagoshi

Hisao Yamashita

Akira Kato

Shinpei Matsuda

Tomoichi Kamo

Fumito Nakajima

Shigeru Azuhata

Shin Tamata

Shuichi Kanno

Toshiaki Arato

Takahiro Tachi

Yasuyoshi Kato

Masato Takeuchi

Shigeo Uno

Takeshi Yasuda

Hideo Okada

Shinzo Ikeda

Noriko Watanabe

Tetsuro Haga

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.

Method for treating organohalogen compounds with catalyst

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.

Method for treating gas containing organohalogen compounds, and catalyst

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.

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.

Poisoning-resistant catalyst, process for production thereof, and

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. is added in 1-20% by weight to the catalyst carrier precursor, followed by precalcining the mixture at the thermal decomposition temperature or higher.

Process for removing nitrogen oxides

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.

Catalyst for removing nitrogen oxides

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.

This invention relates to a method of catalytic combustion using a heat-resistant catalyst and, in particular, relates to a method of catalytic combustion using a heat-resistant catalyst suitable for combustion at a temperature ranging from 800.degree. C. to 1500.degree. C.

Method of catalytic combustion using heat-resistant catalyst

A catalyst comprising precious metal particles supported on a carrier obtained from (a) titania as a first component and (b) as a second component at least one metal oxide selected from oxides of magnesium, strontium, lanthanum, yttrium, cerium, zirconium, silicon and tin, is effective for catalytic combustion of a fuel at a temperature of 400.degree. to 1500.degree. C. with excellent durability.

Catalyst for catalytic combustion

Hydrocarbon oil containing sulfur compounds, for example, lighter petroleum fraction having a boiling point of not higher than 250.degree. C. is hydrodesulfurized to less than 1 ppm with a hydrogenating gas containing 1 to 40% by volume of oxides of carbon (CO.sub.2 and CO) in the presence of a catalyst comprising 3 to 40% by weight of at least one of molybdenum and tungsten, and 2 to 15% by weight of at least one of nickel and cobalt, the balance being titanium oxide. Product gas from steam reforming can be used as the hydrogenating gas.

Hydrodesulfurization of hydrocarbon oil with a catalyst including

A process for steam reforming of hydrocarbons utilizing a catalyst comprising at least 3% by weight, preferably 10, to 30% by weight of nickel per weight of the catalyst, at least 2 mg-atoms of silver per 100 g of the catalyst; if necessary at least one of rare earth elements such as lanthanum, cerium, yttrium, praseodimium, neodimium, or a mixture of rare earth elements in an atomic ratio of the rare earth elements to silver of 10 or less, preferably 0.2 to 2.0; and a heat-resistant oxide carrier such as alumina, silica, magnesia, titania, zirconia, beryllia or thoria.

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Hitachi, Japan

Hiroshi Kawagoshi