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 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:
The present invention is a method for selective reduction of nitrogen oxides in a gas stream with ammonia wherein the ammonia is vaporized prior to contacting it with the carrying fluid. The present invention also comprises a reducing agent dispersion system for use in substantially uniformly mixing a reducing agent with nitrogen oxides in a flue gas stream comprising a header and a plurality of lances. Further, the present invention comprises a novel reactor design for use in selective reduction of nitrogen oxides in a gas stream.
摘要:
The present invention is a method for selective reduction of nitrogen oxides in a gas stream with ammonia wherein the ammonia is vaporized prior to contacting it with the carrying fluid. The present invention also comprises a reducing agent dispersion system for use in substantially uniformly mixing a reducing agent with nitrogen oxides in a flue gas stream comprising a header and a plurality of lances. Further, the present invention comprises a novel reactor design for use in selective reduction of nitrogen oxides in a gas stream.
摘要:
This invention is an emission control system wherein the boiler hosts a reactor which contains one or more catalysts for the purpose of reducing NOx and/or CO in the emissions. The reactor containing the NOx/CO catalysts may be placed at a place where the temperature is in the range of 300-1000° F. The hot flue gas can be diverted using control dampers and blended with colder flue gas inside the boiler to achieve the desired flue gas temperature for the selected catalyst. NOx is removed by the SCR catalyst inside the boiler upon injecting a suitable reducing agent (e.g. ammonia, or hydrocarbons). The CO and NOx catalysts may be used in any order. The emission control system is an integral part of the boiler, and the existing capabilities of the boiler to recover the heat from flue gas, after the catalyst layers, is utilized such that the overall boiler efficiency remains high.
摘要:
A system and method of maintaining an optimal temperature range for a catalyst section in a HRSG comprising placing a portion of the exhaust stream in a heat exchanger and superheater, diverting a second portion around the heat exchanger and superheater, combining the two portions and contacting the two portions with a catalyst section. Alternatively, a system of heat exchangers are employed to address the fluctuating exhaust temperature caused by the intermittent use of the duct burners.
摘要:
A system and method of maintaining an optimal temperature range for a catalyst section in a HRSG comprising placing a portion of the exhaust stream in a heat exchanger and superheater, diverting a second portion around the heat exchanger and superheater, combining the two portions and contacting the two portions with a catalyst section. Alternatively, a system of heat exchangers are employed to address the fluctuating exhaust temperature caused by the intermittent use of the duct burners.
摘要:
A catalyst system and a method for reducing nitrogen oxides in an exhaust gas by reduction with a hydrocarbon or oxygen-containing organic compound reducing agent are provided. The catalyst system contains a silver catalyst and a modifier catalyst, where the modifier catalyst contains a modifier oxide, where the modifier oxide is selected from the group consisting of iron oxide, cerium oxide, copper oxide, manganese oxide, chromium oxide, a lanthanide oxide, an actinide oxide, molybdenum oxide, tin oxide, indium oxide, rhenium oxide, tantalum oxide, osmium oxide, barium oxide, calcium oxide, strontium oxide, potassium oxide, vanadium oxide, nickel oxide, tungsten oxide, and mixtures thereof. The modifier oxide is supported on an inorganic oxide support or supports, where at least one of the inorganic oxide supports is an acidic support. The catalyst system of the silver catalyst and the modifier catalyst provides higher NOx conversion than either the silver catalyst or the modifier catalyst alone.
摘要:
YMn2O5 pseudo-brookite compositions with improved thermal stability and catalytic activity as Zero-PGM (ZPGM) catalyst systems for DOC application are disclosed. Testing of YMn2O5 pseudo-brookite catalysts and YMnO3 perovskite catalysts, including variations of calcination temperatures, are performed under DOC light-off (LO) tests at wide range of space velocity to evaluate catalytic performance, especially level of NO oxidation. The presence of YMn2O5 pseudo-brookite oxides in disclosed ZPGM catalyst compositions is analyzed by x-ray diffraction (XRD) analysis. XRD analyses and LO tests confirm that YMn2O5 pseudo-brookite catalysts exhibit higher catalytic activity and significant improved thermal stability when compared to conventional YMnO3 perovskite catalysts.
摘要翻译:公开了具有改进的热稳定性和催化活性的YMn2O5假片钛矿组合物作为用于DOC应用的Zero-PGM(ZPGM)催化剂体系。 在宽范围的空间速度下,在DOC关闭(LO)试验下进行YMn2O5假片状脆性催化剂和YMnO3钙钛矿催化剂的测试,包括煅烧温度的变化,以评估催化性能,特别是NO氧化水平。 通过X射线衍射(XRD)分析分析了所公开的ZPGM催化剂组合物中存在的YMn 2 O 5假褐煤矿氧化物。 与传统的YMnO3钙钛矿催化剂相比,XRD分析和LO测试证实,YMn2O5假片煤烟石催化剂具有更高的催化活性和显着的改善的热稳定性。
摘要:
Synergized platinum group metals (SPGM) oxidation catalyst systems are disclosed. Disclosed SPGM oxidation catalyst systems may include a washcoat with a Cu—Mn spinel structure and an overcoat including PGM, such as palladium (Pd), platinum (Pt), rhodium (Rh), or combinations thereof, supported on carrier material oxides. SPGM systems show significant improvement in abatement of unburned hydrocarbons (HC) and carbon monoxide (CO), and the oxidation of NO to NO2, which allows reduction of fuel consumption. Disclosed SPGM oxidation catalyst systems exhibit enhanced catalytic activity compared to PGM oxidation systems, showing that there is a synergistic effect between PGM and Cu—Mn spinel composition within the disclosed SPGM oxidation catalyst systems. Disclosed SPGM oxidation catalyst systems may be available for a plurality of DOC applications.