摘要:
A catalyst and a method for selectively reducing nitrogen oxides (“NOx”) with ammonia are provided. The catalyst includes a first component comprising a zeolite or mixture of zeolites selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof; a second component comprising at least one member selected from the group consisting of cerium, iron, copper, gallium, manganese, chromium, cobalt, molybdenum, tin, rhenium, tantalum, osmium, barium, boron, calcium, strontium, potassium, vanadium, nickel, tungsten, an actinide, mixtures of actinides, a lanthanide, mixtures of lanthanides, and mixtures thereof; optionally an oxygen storage material and optionally an inorganic oxide. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at high temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of low levels of nitrogen oxides in exhaust streams. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from gas turbines and gas engines, although the catalyst and the method have broad application to a wide range of gas streams that have excess oxygen and high temperatures. The temperature of exhaust gas from gas turbines and gas engines is high. Both the high temperature and the low levels of inlet NOx are challenging for selective catalytic reduction (SCR) catalysts.
摘要:
A catalyst and a method for selectively reducing nitrogen oxides (“NOx”) with ammonia are provided. The catalyst includes a first component comprising a zeolite or mixture of zeolites selected from the group consisting of ZSM-5, ZSM-11, ZSM-12, ZSM-18, ZSM-23, MCM-zeolites, mordenite, faujasite, ferrierite, zeolite beta, and mixtures thereof; a second component comprising at least one member selected from the group consisting of cerium, iron, copper, gallium, manganese, chromium, cobalt, molybdenum, tin, rhenium, tantalum, osmium, barium, boron, calcium, strontium, potassium, vanadium, nickel, tungsten, an actinide, mixtures of actinides, a lanthanide, mixtures of lanthanides, and mixtures thereof; optionally an oxygen storage material and optionally an inorganic oxide. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at high temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of low levels of nitrogen oxides in exhaust streams. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from gas turbines and gas engines, although the catalyst and the method have broad application to a wide range of gas streams that have excess oxygen and high temperatures. The temperature of exhaust gas from gas turbines and gas engines is high. Both the high temperature and the low levels of inlet NOx are challenging for selective catalytic reduction (SCR) catalysts.
摘要:
Embodiments of the present disclosure include a catalyst for the conversion of CO and/or hydrocarbons in an exhaust stream including a Sn compound selected from the group consisting of a binary composition comprising Sn and Ti, a ternary composition comprising Sn, Ti and Zr, and mixtures of any thereof. In those embodiments, the binary composition may include Sn(X)Ti(y)O2, wherein x+y=1, 0.85>y>0. In other embodiments of the present disclosure, the Sn compound includes a ternary composition including Sn(a)Ti(b)Zr(c)O2, wherein a is 0.25, b is 0.25 and c is 0.5. Certain embodiments of this disclosure include a method for the conversion of CO in an exhaust stream, including contacting an exhaust stream containing CO with the catalyst described above containing a Sn compound. In other embodiments, the exhaust stream includes hydrocarbons.
摘要:
A catalyst and a method for selectively reducing nitrogen oxides with ammonia are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a zeolite. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at low temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of nitrogen oxides in exhaust streams, and are not significantly influenced by the NO/NO2 ratio. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from diesel vehicles, although the catalyst and the method have broad application to a wide range of gas streams that contain nitrogen oxides. The temperature of exhaust gas from diesel vehicles is low, and the exhaust gas generally has a high NO/NO2 ratio. Both the low temperature and the high NO/NO2 ratio are challenging for selective catalytic reduction (SCR) catalysts.
摘要:
A zeolite based SCR catalyst for NOx reduction using a reducing agent for treating exhaust streams from industrial and commercial boilers is provided. The reactor system has a zeolite based catalyst arranged in catalyst cassettes in a modular fashion where the reactor containing the zeolite based SCR catalyst cassettes is placed in a perpendicular direction to the exhaust exiting the industrial and/or commercial boiler. The catalyst selectively reduces nitrogen oxides to nitrogen with a reducing agent at low to medium temperatures. The reactor results in high NOx conversions and very low ammonia slip and is active for a wide range of boiler firing conditions. Boilers with low NOx and/or ultra low NOx burners can be replaced with a standard conventional burner for overall emissions reduction performance, efficiency improvements and energy savings. Boilers with low NOx and ultra low NOx burners can also be fitted with this zeolite based SCR catalyst reactor for additional NOx reductions and energy savings.
摘要:
A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat. Washcoats prepared from colloidal aluminum oxide may have higher surface areas and pore volumes loadings than washcoats containing aluminum oxide prepared from aluminum nitrate.
摘要:
A DPF with an SCR catalyst and a method for selectively reducing nitrogen oxides with ammonia, filtering particulates, and reducing the ignition temperature of soot on a DPF are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a component characterized by increased surface acidity. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia and oxidizes soot at low temperatures. The catalyst has high hydrothermal stability.
摘要:
A catalyst and a method for selectively reducing nitrogen oxides with ammonia are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a zeolite. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at low temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of nitrogen oxides in exhaust streams, and are not significantly influenced by the NO/NO2 ratio. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from diesel vehicles, although the catalyst and the method have broad application to a wide range of gas streams that contain nitrogen oxides. The temperature of exhaust gas from diesel vehicles is low, and the exhaust gas generally has a high NO/NO2 ratio. Both the low temperature and the high NO/NO2 ratio are challenging for selective catalytic reduction (SCR) catalysts.
摘要:
A catalyzed diesel particulate filter (CDPF) and a method for filtering particulates from diesel engine exhaust are provided, where the catalyzed diesel particulate filter includes a substrate and a catalyst composition, where the catalyst composition contains at least one first component, at least one second component, and at least one third component, where the first component is at least one first component selected from the group consisting of cerium and a lanthanide and mixtures thereof, the at least one second component is selected from the group consisting of cobalt, copper, manganese and mixtures thereof; and the third component comprises strontium, where the first component, the second component, and the third component are in an oxide form after calcination. The catalyst on the catalyzed diesel particulate filter lowers the temperature at which particulates are removed from the CDPF by oxidizing the particulates on the filter. The catalyzed diesel particulate filter may also include a washcoat. Washcoats prepared from colloidal aluminum oxide may have higher surface areas and pore volumes loadings than washcoats containing aluminum oxide prepared from aluminum nitrate.
摘要:
A catalyst and a method for selectively reducing nitrogen oxides with ammonia are provided. The catalyst includes a first component of copper, chromium, cobalt, nickel, manganese, iron, niobium, or mixtures thereof, a second component of cerium, a lanthanide, a mixture of lanthanides, or mixtures thereof, and a zeolite. The catalyst may also include strontium as an additional second component. The catalyst selectively reduces nitrogen oxides to nitrogen with ammonia at low temperatures. The catalyst has high hydrothermal stability. The catalyst has high activity for conversion of nitrogen oxides in exhaust streams, and are not significantly influenced by the NO/NO2 ratio. The catalyst and the method may have special application to selective reduction of nitrogen oxides in exhaust gas from diesel vehicles, although the catalyst and the method have broad application to a wide range of gas streams that contain nitrogen oxides. The temperature of exhaust gas from diesel vehicles is low, and the exhaust gas generally has a high NO/NO2 ratio. Both the low temperature and the high NO/NO2 ratio are challenging for selective catalytic reduction (SCR) catalysts.
摘要翻译:提供催化剂和用氨选择还原氮氧化物的方法。 催化剂包括铜,铬,钴,镍,锰,铁,铌或其混合物的第一组分,铈的第二组分,镧系元素,镧系元素或其混合物的混合物以及沸石。 催化剂还可以包括作为另外的第二组分的锶。 催化剂在低温下用氨选择性还原氮氧化物至氮气。 该催化剂具有很高的水热稳定性。 该催化剂对排气流中的氮氧化物的转化具有高活性,并且不受NO / NO 2 H 2比的显着影响。 催化剂和方法可以特别适用于选择性还原来自柴油车辆的废气中的氮氧化物,尽管催化剂和方法广泛应用于含有氮氧化物的各种气流。 来自柴油车辆的废气的温度低,排气通常具有高的NO / NO 2 2比。 低温和高NO / NO 2 2比都是选择性催化还原(SCR)催化剂的挑战。