Abstract: Provided is a method for producing a NOx removal catalyst for high-temperature exhaust gas, comprising: calcining a mixture comprising ZrO2 and TiO2 with a ZrO2 content ratio of 15% by weight to 55% by weight at 500±15° C. to obtain a composite oxide support and supporting tungsten oxide on the composite oxide, support, followed by calcination at 650±15° C. to obtain a powder catalyst.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: A separation and recovery method that enables titanium and tungsten to be separated and recovered from a used DeNOx catalyst in high yield. Specifically, a method of separating and recovering metal elements that includes a first heating step of heating a DeNOx catalyst containing titanium, tungsten, vanadium and iron in a chlorine atmosphere, thereby removing the vanadium and the iron from the DeNOx catalyst, and a second heating step, performed after the first heating step, of heating the DeNOx catalyst in a chlorine atmosphere while the catalyst is exposed to a gas of a hydrocarbon compound (excluding CH4) or an oxygen-containing carbon compound, thereby volatilizing the tungsten and the titanium from the DeNOx catalyst, and recovering the tungsten and the titanium from the DeNOx catalyst.

Abstract: An exhaust gas treatment catalyst for removal of one or more pollutants in an exhaust gas, the catalyst comprising: a SO3-reducing catalyst powder which removes the above-described pollutants; and a diluent powder which is not the SO3-reducing catalyst powder nor a catalyst for reactions between exhaust gas components and a reagent, wherein the SO3-reducing catalyst powder is dispersed in the diluent powder.

Abstract: A NOx removal catalyst for high-temperature flue gas according to the present invention is a NOx removal catalyst for high-temperature flue gas that contains nitrogen oxide in which tungsten oxide with the number of molecular layers of tungsten oxide (WO3) being five or less is supported on a complex oxide carrier containing titanium oxide. Even when high-temperature denitration is continued, a bonding force with a carrier of WO3 can be properly maintained and volatilization can be suppressed while maintaining a high NOx removal performance. For example, the NOx removal catalyst is particularly suitable for reducing and removing nitrogen oxide contained in high-temperature gas discharged from a thermal power plant and a high-temperature boiler.

Abstract: The method includes a pretreatment step during an operation of a boiler in which in a predetermined period of time before shutdown of the boiler, a part of combustion gas that has bypassed an economizer provided in a flue gas duct for flue gas from the boiler is supplied to an upstream of a NOx removal device having a NOx removal catalyst and mixed with the combustion flue gas from the economizer to generate mixed gas having a predetermined temperature equal to or higher than 360° C. (360° C. to 450° C.), the mixed gas is introduced into the NOx removal catalyst, thereby decomposing VOSO4 adhering to and accumulating on the NOx removal catalyst into V2O5.

Abstract: An air pollution control apparatus includes at least one denitration catalyst layer for reducing the amounts of nitrogen oxides in flue gas from a boiler and oxidizing mercury with hydrogen chloride sprayed into the flue gas. Spraying pipe headers 51 are disposed in a flue gas duct 19. The spraying pipe headers 51 are inserted into the flue gas duct 19 and arranged in a direction orthogonal to the direction of a gas flow in the flue gas duct 19. At least four spray nozzles 52-1 to 52-4 are disposed at intervals on the spraying pipe header 51 to form a vertical vortex flow 53 in the gas flow direction. A swirling diffuser plate is disposed on an opening side of the spray nozzles to form the vertical vortex flow in the gas flow direction, wherein the swirling diffuser plate has a flat shape at one side parallel to the spraying pipe header and a wavy shape corresponding to the nozzle intervals on the header at the other side. The diffusion of hydrogen chloride is thereby facilitated in a rapid manner.

Abstract: Provided is an exhaust gas treatment catalyst including: a de-NOx catalyst; and a coating layer being provided on a surface of the de-NOx catalyst and containing at least one selected from the group consisting of alkali metal carbonates and alkaline earth metal carbonates. In a method for regenerating an exhaust gas treatment catalyst of the present invention, the coating layer of the de-NOx catalyst on which VOSO4 is deposited is removed with an acid, and after the removal of the coating layer, a coating layer containing at least one selected from the group consisting of alkali metal carbonates and alkaline earth metal carbonates is again provided.

Abstract: A NOx removal catalyst for high-temperature flue gas according to the present invention is a NOx removal catalyst for high-temperature flue gas that contains nitrogen oxide in which tungsten oxide with the number of molecular layers of tungsten oxide (WO3) being five or less is supported on a complex oxide carrier containing titanium oxide. Even when high-temperature denitration is continued, a bonding force with a carrier of WO3 can be properly maintained and volatilization can be suppressed while maintaining a high NOx removal performance. For example, the NOx removal catalyst is particularly suitable for reducing and removing nitrogen oxide contained in high-temperature gas discharged from a thermal power plant and a high-temperature boiler.

Abstract: In a NOx removal catalyst used for removing nitrogen oxides in flue gas, when a silica (Si) component as an inhibitor that causes an increase in a SO2 oxidation rate accumulates on a surface of the catalyst, the silica component accumulating on the surface of the catalyst is dissolved, thereby regenerating the catalyst. Accordingly, the inhibitor such as the silica component covering the surface of the NOx removal catalyst can be removed, thereby enabling to provide a catalyst without having an increase in the SO2 oxidation rate of the regenerated NOx removal catalyst.

Abstract: A NOx reduction catalyst carrier yields a NOx reduction catalyst with an improved permissible dose of poisoning substances such as arsenic. More specifically, the present invention relates to a NOx reduction catalyst carrier comprising TiO2, having a honeycomb structure and having a specific surface area greater than 100 m2/g.

Abstract: In a NOx removal catalyst used for removing nitrogen oxide in flue gas, when a silica (Si) component as an inhibitor that causes an increase in an SO2 oxidation rate accumulates on a surface of the NOx removal catalyst, the silica component accumulating on the surface of the NOx removal catalyst is dissolved, thereby regenerating the catalyst. Accordingly, the inhibitor such as the silica component covering the surface of the NOx removal catalyst can be removed, thereby enabling to provide a catalyst without having an increase in the SO2 oxidation rate of the regenerated NOx removal catalyst.

Abstract: Provided are an exhaust gas treatment catalyst for denitrifying an exhaust gas including sulfur oxides and vanadium discharged from a heavy oil combustion boiler, including: a support comprising any one or all of titanium oxide and silica wherein a content of silica is from 10% to 20%, and an active component supported in the support and comprising one selected from the group consisting of vanadium and tungsten.

Abstract: A separation and recovery method that enables titanium and tungsten to be separated and recovered from a used DeNOx catalyst in high yield. Specifically, a method of separating and recovering metal elements that includes a first heating step of heating a DeNOx catalyst containing titanium, tungsten, vanadium and iron in a chlorine atmosphere, thereby removing the vanadium and the iron from the DeNOx catalyst, and a second heating step, performed after the first heating step, of heating the DeNOx catalyst in a chlorine atmosphere while the catalyst is exposed to a gas of a hydrocarbon compound (excluding CH4) or an oxygen-containing carbon compound, thereby volatilizing the tungsten and the titanium from the DeNOx catalyst, and recovering the tungsten and the titanium from the DeNOx catalyst.

Abstract: A NOx reduction catalyst carrier yields a NOx reduction catalyst with an improved permissible dose of poisoning substances such as arsenic. More specifically, the present invention relates to a NOx reduction catalyst carrier comprising TiO2, having a honeycomb structure and having a specific surface area greater than 100 m2/g.

Abstract: An air pollution control apparatus 10 according to an embodiment of the present invention has a denitration catalyst layer 13 that removes NOx in flue gas 12, and atomizes HCl into the flue gas 12 to oxidize Hg, and also includes a swirling-flow generating member 30A that includes a swirling-flow generating-member body being partitioned to correspond to each passage of the denitration catalyst layer 13 and a plurality of swirling-flow generating vanes arranged on the partition inner walls to generate a turbulent flow, on an inlet 13a side of the denitration catalyst layer 13. With this configuration, a laminar flow of the flue gas 12 in a flue gas duct 19 is changed to a swirling flow, thereby enabling to increase a contact time between the flue gas 12 and a denitration catalyst and to improve the oxidation reaction efficiency between Hg in the flue gas 12 and the denitration catalyst.

Abstract: A catalyst for treating exhaust gases containing nitrogen monoxide, carbon monoxide and volatile organic compounds includes a plurality of layers, an upper layer of which has an active component contained uniformly therein and a lower layer of which has no active component contained therein. The catalyst is obtained through the steps of: forming the lower layer by coating the surface of substrate with a slurry of a porous inorganic compound, followed by drying; and forming the upper layer, which is to be the top surface of the catalyst, by coating the surface of the lower layer with a slurry of a porous inorganic compound that has the active component composed of one or more precious metals supported thereon, followed by drying. The oxidation power of the resulting catalyst is enhanced without increasing the amount of precious metal supported thereon.

Abstract: It is intended to provide an exhaust gas treatment system, which allows for VOC removal at lower temperatures and thereby improves the durability of catalysts and suppresses carbon monoxide generation at the final outlet of the system. The present invention provides a treatment system of an exhaust gas containing a nitrogen oxide, carbon monoxide, and a volatile organic compound comprising: an exhaust gas treatment means for removing the nitrogen oxide by reduction with ammonia and partially oxidizing the VOC to CO; and a CO/VOC removal means for oxidizing the CO and partially unreacted VOC, in this order from the upstream flow of the exhaust gas.

Abstract: In an exhaust gas treatment, the amount of a highly corrosive mercury-halogenating agent to be added is reduced with the mercury-removing efficiency maintained high. A mercury-halogenating agent (40) and ammonia (30) are added to combustion exhaust gas from a boiler, the exhaust gas containing NOx, SOx and mercury. The exhaust gas is brought into contact with a CO/HC oxidation catalyst (50) and is then subjected to reduction denitration (60) in the presence of a solid catalyst. Thereafter, metallic mercury is oxidized to halogenated mercury. Then, the exhaust gas is wet-desulfurized (100) with the alkaline absorbing solution, and the halogenated mercury is removed.

Abstract: Provided is a catalyst for treating exhaust gas capable of reducing the amount of a highly corrosive mercury-chlorinating agent to be added while keeping the mercury oxidation efficiency high in an exhaust gas treatment. By the catalyst for treating exhaust gas, nitrogen oxide in the exhaust gas is removed upon contact with ammonia serving as a reducing agent, and mercury is oxidized using a halogen serving as an oxidant. The catalyst includes: TiO2 as a support; an oxide of at least one selected from the group consisting of V, W and Mo, which is supported as an active component on the support; and at least one selected from the group consisting of Bi, P, and compounds containing Bi and/or P, which is supported as a co-catalyst component on the support.