摘要:
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.
摘要:
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.
摘要:
The present invention relates to a method for sintering oxidized titanium powder and an active metallic component containing oxidized molybdenum as a binder for oxidized titanium granules. The active metallic component comprises one or more than one selected from a group consisting of V.sub.2 O.sub.3, Fe.sub.2 O.sub.3, WO.sub.3, Co.sub.2 O.sub.3, NiO, Cr.sub.2 O.sub.3, CeO.sub.2, SnO.sub.2, CuO, MoO.sub.3, Pt, Pd, Rh, Ru, Ir and Re.The method comprising the steps of:depositing vaporized oxidized molybdenum on the oxidized titanium powder in an atmosphere of molybdenum vapor at temperatures of 460.degree. to 650.degree. C.,forming a powdery mixture comprising the oxidized titanium powder with the deposited oxidized molybdenum and said active metallic component,adding water sufficient to make a viscous material of the powdery mixture,kneading the viscous material,shaping an article by using the viscous material, andcalcining the article to produce a product.
摘要翻译:本发明涉及氧化钛粉末和含有氧化钼作为氧化钛颗粒的粘合剂的活性金属成分的烧结方法。 活性金属组分包括选自V 2 O 3,Fe 2 O 3,WO 3,Co 2 O 3,NiO,Cr 2 O 3,CeO 2,SnO 2,CuO,MoO 3,Pt,Pd,Rh,Ru,Ir和Re中的一种或多种。 该方法包括以下步骤:在460℃至650℃的温度下,在钼蒸气气氛下,将氧化的氧化钼沉积在氧化的钛粉末上,形成包含氧化的钛粉末与沉积的氧化钼和所述活性物质的粉末混合物 金属组分,加入足以制备粉状混合物的粘性材料的水,捏合粘性物质,通过使用粘性物质成型物品,并煅烧制品以制备产品。
摘要:
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.
摘要:
The concentrations of NO and NO.sub.2 in nitrogen oxides contained in an exhaust gas are adjusted to substantially equal mol concentrations, whereupon the exhaust gas is held in contact with a metallic oxide catalyst together with ammonia. Owing to the adjustment of the NO and NO.sub.2 concentrations in the nitrogen oxides, the reaction rate is enhanced, and the nitrogen oxides are reduced even at a low temperature. The adjustment of the concentrations of NO and NO.sub.2 in the nitrogen oxides is done by the oxidation of NO with ozone, the catalytic oxidation of NO with air or oxygen, the addition of nitric acid, the addition of NO or NO.sub.2, etc.
摘要:
Ammonia is added to combustion flue gas containing nitrogen and sulfur oxides and the gas is brought into contact with a catalyst which contains titanium or tin oxide, or a mixture of the two, as a main component at a temperature between 150 .about. 330.degree. C.Nitrogen oxides are reduced to nitrogen and water, and sulfur oxides are deposited as ammonium sulfates, on the surface of the catalyst which causes a decrease in the ability of the catalyst.A part of the catalyst is removed continuously or intermittently from a catalyst bed and fed to a regeneration tower where it is treated with a hot gas having a temperature of 350 .about. 600.degree. C. The ammonium sulfates deposited on the catalyst are decomposed into SO.sub.3 and NH.sub.3. The SO.sub.3 is adsorbed by an SO.sub.3 absorbent and the NH.sub.3 is returned to the combustion flue gas to be treated.
摘要:
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.
摘要:
In a molten carbonate fuel cell, an anode or cathode is made of a sintered material containing a nickel oxide and/or cobalt oxide and a rare earth element oxide. This anode or cathode has a high activity and is stable at high temperatures.
摘要:
A catalyst or a catalyst structure for removing nitrogen oxides contained in exhaust gases, having a small pressure loss and hard to cause ash deposition, and a process for producing the same are provided, which catalyst comprises a mixture of a catalyst composition of titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, and inorganic fibers, the clearances of the inorganic fibers are filled with said catalyst composition; the ration by weight of said catalyst composition to said inorganic fibers is 3 or more; and the apparent density of said catalyst is 0.8 g/cm.sup.3 or more; and which process comprises providing a composition containing titanium oxide and at least one member of oxides of vanadium, molybdenum and tungsten, calcining said composition at 500.degree.-650.degree. C., crushing the calcined material so that powder of 20.mu. or less can occupy 90% by weight or more of the crushed material, adding water to the crushed material to form a slurry, impregnating an inorganic fiber sheet with the above slurry, placing the resulting sheet between porous molds, drying and molding it, and clacining the resulting molded material at 300.degree.-650.degree. C.
摘要:
A catalyst for purifying an exhaust gas includes a first component having activity for reducing nitrogen oxides with ammonia and a second component having at least one of activity for forming nitrogen oxide from ammonia and activity for forming carbon dioxide from carbon monoxide. The first component is a composition containing an oxide of at least one member selected from titanium, vanadium, tungsten and molybdenum and the second component is a composition containing a salt of a noble metal selected from platinum, palladium and rhodium or any one of these noble metals supported on a porous material selected from zeolites, alumina and silica. The invention further provides a method for purifying an exhaust gas containing NOx, CO and leak NH.sub.3 using the catalyst.