Abstract: A catalyst for treating exhaust gases having excellent durability and performance for removing nitrogen oxides and organic halogen compounds and a low SO2 oxidation rate, a titanium oxide suitable for preparing the catalyst and a method for treating exhaust gases containing nitrogen oxides and/or organic halogen compounds using the catalyst are provided. The BET specific surface areas of the titanium oxide and the catalyst for treating exhaust gases are in the range of 85 to 250 m2/g and in the range of 50 to 200 m2/g respectively. The titanium oxide and the catalyst for treating exhaust gases have each a ratio in the range of 15 to 145%, the ratio of the intensity of the peak indicating an anatase crystal present in the range of 2?=24.7° to 2?=25.7° of powder X-ray diffraction thereof (Ia) to the intensity of the peak indicating an anatase crystal present in the range of 2?=24.7° to 2?=25.

Abstract: The present invention has an object to more enhance the efficiency of the purification of the CO-containing exhaust gases with a catalytic-component-supporting type catalyst, particularly, to enable both achievement of high purification efficiency and long-term stable maintenance of high purification efficiency without increasing the quantity of the catalytic component as supported. As a means of achieving this object, a process for purification of exhaust gases, according to the present invention, is a process for purification of exhaust gases to remove CO therefrom, and is characterized by comprising the step of bringing the exhaust gases into contact with a catalyst layer at a temperature of 250 to 600° C., a pressure drop of not more than 100 mmH2O, and a linear velocity of 0.5 to 10 m/s, wherein the catalyst layer includes a honeycomb-structural catalyst having an opening size of 1.0 to 3.0 mm, an opening ratio of 60 to 80%, and an inner wall thickness of less than 2 mm.

Abstract: A catalyst for treating exhaust gases having excellent durability and performance for removing nitrogen oxides and organic halogen compounds and a low SO2 oxidation rate, a titanium oxide suitable for preparing the catalyst and a method for treating exhaust gases containing nitrogen oxides and/or organic halogen compounds using the catalyst are provided. The BET specific surface areas of the titanium oxide and the catalyst for treating exhaust gases are in the range of 85 to 250 m2/g and in the range of 50 to 200 m2/g respectively. The titanium oxide and the catalyst for treating exhaust gases have each a ratio in the range of 15 to 145%, the ratio of the intensity of the peak indicating an anatase crystal present in the range of 2?=24.7° to 2?=25.7° of powder X-ray diffraction thereof (Ia) to the intensity of the peak indicating an anatase crystal present in the range of 2?=24.7° to 2?=25.

Abstract: A catalyst for purification of CO-containing exhaust gases, includes a metal oxide as a support and a catalytic component A being supported thereon as a catalytic component and including a specific noble metal element; wherein the support includes a titanium-containing oxide as the metal oxide and is a monolithically molded type porous honeycomb support obtained by a process including the steps of extrusion-molding and then calcining materials of the support; and wherein the catalytic component A is distributed with a quantitatively great inclination toward surfaces of the catalyst. A process for purification of exhaust gases to remove CO therefrom, includes the step of bringing the exhaust gases into contact with the catalyst.

Abstract: The present invention has an object to more enhance the efficiency of the purification of the CO-containing exhaust gases with a catalytic-component-supporting type catalyst, particularly, to enable both achievement of high purification efficiency and long-term stable maintenance of high purification efficiency without increasing the quantity of the catalytic component as supported. As a means of achieving this object, a process for purification of exhaust gases, according to the present invention, is a process for purification of exhaust gases to remove CO therefrom, and is characterized by comprising the step of bringing the exhaust gases into contact with a catalyst layer at a temperature of 250 to 600° C., a pressure drop of not more than 100 mmH2O, and a linear velocity of 0.5 to 10 m/s, wherein the catalyst layer includes a honeycomb-structural catalyst having an opening size of 1.0 to 3.0 mm, an opening ratio of 60 to 80%, and an inner wall thickness of less than 2 mm.

Abstract: Disclosed is a catalyst for purification of CO-containing exhaust gases, comprising: a metal oxide as a support and a catalytic component A being supported thereon as a catalytic component and including a specific noble metal element; wherein the support includes a titanium-containing oxide as the metal oxide and is a monolithically molded type porous honeycomb support obtained by a process including the steps of extrusion-molding and then calcining materials of the support; and wherein the catalytic component A is distributed with a quantitatively great inclination toward surfaces of the catalyst. Further disclosed is a process for purification of exhaust gases to remove CO therefrom, comprising the step of bringing the exhaust gases into contact with the above catalyst.

Abstract: In an apparatus for selectively reduction-removing nitrogen oxides in exhaust gas in presence of catalyst by spraying aqueous solid reducing agent solution into exhaust gas flowing through a duct to mix the reducing agent into exhaust gas, the present invention prevents nozzle-clogging caused by the reducing agent or its reaction product, permits stable and continuous spraying and uniform mixing of the reducing agent solution into exhaust gas, and thus removes nitrogen oxides at a high efficiency. The nozzle is cooled by supplying at least one of water and gas before supplying the solution into the nozzle. Upon discontinuing supply of the solution to the nozzle, at least one of water and gas is supplied to remove the solution remaining in the nozzle. The solution stored at high concentration is sprayed after diluting it with water in the course of transfer for spraying. A line for supplying water for diluting is added to the line for supplying the solution.

Abstract: The present invention provides a catalyst having excellent capability of removing organic halogen compounds such as dioxins, a method for preparing the catalyst, and a method for removing organic halogen compounds using the catalyst. A catalyst for removing organic halogen compounds comprises titanium oxide as a catalyst component and has pores including a group of pores having a pore diameter distribution peak in a range of 0.01 to 0.05 gm and another group of pores having a pore diameter distribution peak in a range of 0.1 to 0.8 .mu.m. Another catalyst for removing organic halogen compounds comprises titanium oxide and a titanium-silicon composite oxide as catalyst components and has pores including a group of pores having a pore diameter distribution peak in a range of 0.01 to 0.05 .mu.m and another group of pores having a pore diameter distribution peak in a range of 0.8 to 4 .mu.m.

Abstract: This invention discloses an adsorbent ideal or the removal of nitrogen oxides (NO.sub.x : nitrogen monoxide and nitrogen dioxide), particularly nitrogen dioxide, from an exhaust gas containing the nitrogen oxides at low concentrations and a method for efficient removal of nitrogen oxides, particularly nitrogen dioxide, from an exhaust gas containing the nitrogen oxides at low concentrations by the use of the adsorbent. The adsorbent either comprises at least one noble metal selected from the group consisting of Pt, Au, Ru, Rh, and Pd and/or a compound thereof supported on a carrier or comprises the noble metal component and an oxide of at least one heavy metal selected from the group consisting of Mn, Fe, Co, Ni, Cu, Zn and Pb, which may be supported on the carrier, if necessary.

Abstract: There is provided a denitration catalyst excellent in denitration activity and durability in a high temperature region, for catalytically reducing NOx in an exhaust gas using a reducing agent such as ammonia. This denitration catalyst is (1) one containing a titanium-tungsten oxide obtained by coprecipitating a soluble titanium compound and a soluble tungsten compound from an aqueous medium under the conditions of a temperature of 60.degree. C. or less and a pH of the range of 5 to 8, and drying and calcining to coprecipitate formed; or (2) one comprising said titanium-tungsten oxide (component A), and an oxide of at least one element (component B) selected from the group consisting of cerium (Ce), lanthanum (La), praseodymium (Pr), neodymium (Nd), nickel (Ni) and tin (Sn).

Abstract: A catalyst for the purification of an exhaust gas by the removal, through selective reduction, of nitrogen oxides present in the exhaust gas, which comprises (A) 80 to 95% by weight of a sulfur oxide-containing catalytic oxide obtained by thermally treating at least one hydrous oxide compound selected from the group consisting of binary hydrous oxide compound of titanium and silicon, binary hydrous oxide compound of titanium and zirconium and ternary hydrous oxide compound of titanium, zirconium and silicon in the presence of at least one sulfur compound selected from the group consisting of sulfuric acid and ammonium sulfate, (B) 0 to 5% by weight of a catalytic oxide comprising vanadium oxide, (C) 1 to 15% by weight of a catlytic oxide comprising the oxide of at least one metal selected form the group consisitng of tungsten, molybdenum, tin and cerium.

Abstract: A metal-impregnated refractory product of this invention has high slag attack, gas attack, and spalling resistances and is used in various types of molten metal treatment vessels. A material of refractory particles mainly consisting of MgO or Al.sub.2 O.sub.3 is formed and heated by a suitable method to obtain a porous material body containing at least 4 vol % of open pores. A metal or an alloy mainly consisting of at least one type of a metal selected from the group consisting of iron, chromium, and nickel is impregnated in the porous material body at a ratio of 25 vol % or more of the open pores. The metal is filled in pores present in a region from the surface to at least a predetermined depth. The metal-impregnated refractory product can withstand various high-temperature damages and can be stably used over a long time period.

Abstract: A catalyst for the purification of a gas containing ozone or a component of offensive odor is composed of (A) a composite oxide comprising (a) titanium and (b) at least one element selected from the group consisting of Si, Zr, and P and (B) at least one element selected from the group consisting of Mn, Fe, Co, Ni, Ag, Pt, Pd, and Rh.

Abstract: A honeycomb catalyst for effecting catalytic reduction and removal of nitrogen oxides in waste gas in the presence of ammonia, which homeycomb catalyst (I) contains a catalytically active substance comprising 60 to 99.5% by weight of a binary oxide containing titanium and silicon and 40 to 0.5% by weight of the oxide of at least one metal selected from the group consisting of vanadium, tungsten, molybdenum, copper, manganese, cerium, and tin, (II) possesses an opening ratio in the cross section of said catalyst in the range of 80 to 90%, (III) has a thickness of partition walls separating through holes in the range of 0.2 to 0.8 mm, and (IV) possesses pores comprising substantially two independent pore groups each of a uniform pore diameter, such that the pore volume occupied by one pore group having a pore diameter in the range of 0.01 to 0.03 .mu.

Abstract: A waste gas-treating catalyst produced by coating the gas inlet side leasing end part of an integrally formed titanium-containing porous nitrogen oxide removing catalyst with at least one sol selected from the group consisting of zirconia sol and zirconium silicate sol, drying and/or calcining the coated catalyst.

Abstract: The present invention concerns a method of removing nitrogen oxides in exhaust gases from a diesel engine by using a catalyst in a reacter under the presence of ammonia, wherein a humidity of in-take air as a specific factor and one or more of engine power, fuel consumption amount of engine, temperature of engine in-take air and exhaust gas temperature as selective factors are measured respectively as the measuring factors and the flow rate of ammonia is controlled based on measured values and ammonia is supplied to an exhaust gas flow channel from the engine to the reactor.

Abstract: The present invention concerns a method of removing nitrogen oxides in exhaust gases from a diesel engine by using a catalyst in a reacter under the presence of ammonia, wherein a humidity of in-take air as a specific factor and one or more of engine power, fuel consumption amount of engine, temperature of engine in-take air and exhaust gas temperature as selective factors are measured respectively as the measuring factors and the flow rate of ammonia is controlled based on measured values and ammonia is supplied to an exhaust gas flow channel from the engine to the reactor.

Abstract: A method for the removal of nitrogen oxides from the exhaust gas of a diesel engine through catalytic reduction by the use of honeycomb catalyst in the presence of ammonia, which method comprises feeding ammonia into said exhaust gas proportionately to the product of the revolution number of said diesel engine multiplied by the torque of said diesel engine.

Abstract: A method of cleaning an exhaust gas containing nitrogen oxides, carbon monoxide and an excess of molecular oxygen, which comprises passing the exhaust gas together with ammonia over a catalyst comprising (A) 60 to 99.9% by weight of a catalytic oxide composed of a titanium containing oxide, (B) 0.1 to 20% by weight of a catalytic oxide composed of at least one metal oxide selected from the group consisting of oxides of copper, manganese and chromium and (C) 0 to 20% by weight of a catalytic oxide composed of at least one metal oxides selected from the group consisting of oxides of vanadium, tungsten, molybdenum, cerium and tin at a temperature of 200.degree. to 500.degree. C.

Abstract: The invention concerns a casting vessel having a basic lining, and usage thereof. For putting in practice the casting vessel employing basic refractories as a lining material and in order to avoid such phenomena as exfoliation or others caused by thermal stress generated in the inside of the lining, a backing between the lining and an outer shell is partially or entirely composed of cushion material having thickness within specific range, thereby to absorb said stress and save a life of the lining, and further temperature within the casting vessel is kept above determined temperature before it holds molten metal, thereby to make more efficient use of the life of the basic lining.