WO2014055858A1 - Système de réduction catalytique sélective - Google Patents

Système de réduction catalytique sélective Download PDF

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Publication number
WO2014055858A1
WO2014055858A1 PCT/US2013/063446 US2013063446W WO2014055858A1 WO 2014055858 A1 WO2014055858 A1 WO 2014055858A1 US 2013063446 W US2013063446 W US 2013063446W WO 2014055858 A1 WO2014055858 A1 WO 2014055858A1
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WO
WIPO (PCT)
Prior art keywords
injection
urea
duct
continuous duct
temperature
Prior art date
Application number
PCT/US2013/063446
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English (en)
Inventor
Jeffrey Michael Broderick
Scott H. Lindemann
James M. Valentine
Original Assignee
Combustion Components Associates, Inc.
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Filing date
Publication date
Application filed by Combustion Components Associates, Inc. filed Critical Combustion Components Associates, Inc.
Publication of WO2014055858A1 publication Critical patent/WO2014055858A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/8621—Removing nitrogen compounds
    • B01D53/8625—Nitrogen oxides
    • B01D53/8631—Processes characterised by a specific device
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/86—Catalytic processes
    • B01D53/90—Injecting reactants
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/003—Arrangements of devices for treating smoke or fumes for supplying chemicals to fumes, e.g. using injection devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F23J15/04—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material using washing fluids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2067—Urea
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/40—Nitrogen compounds
    • B01D2257/404—Nitrogen oxides other than dinitrogen oxide
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2219/00—Treatment devices
    • F23J2219/10—Catalytic reduction devices

Definitions

  • the present invention relates generally to the reduction of nitrogen oxide (NOx) emissions from small industrial, commercial and electric utility boilers and other lean burn stationary combustion sources. More particularly, the present invention relates to a system and method in which urea is converted to ammonia for use in NOx reduction by selective catalytic reduction (SCR). BACKGROUND OF THE INVENTION [0002] The reduction of nitrogen oxide (“NOx”) emissions from small industrial, commercial and electric utility boilers and other lean burn stationary combustion sources continues to be a challenge.
  • NOx nitrogen oxide
  • 5,282,355 describes the prior art as using NOx free exhaust extracted by an exhaust gas recirculation fan to vaporize aqueous ammonia in a vaporizer from which it is injected into the flue upstream of a catalyst layer via an ammonia vapor pipe. He identifies aqueous urea as a precursor to aqueous ammonia which can also be vaporized by NOx free exhaust. For aqueous based solutions of ammonia, Yamaguchi suggests that 0.5-1.0 seconds are required to vaporize the ammonia solution and Yamaguchi does not address the time required for complete decomposition and gasification of an aqueous solution of urea.
  • Yamaguchi identifies concerns about the formation and deposition of solids from the reaction of ammonia with other exhaust gas species and so proposes using superheated steam from the boiler or other source to provide the heat to vaporize the aqueous ammonia or its precursor in a vaporizer.
  • the use of steam from a boiler has a penalty associated with removing steam from the heat or power generation process and also with the cost of preparing de mineralized boiler makeup water to replace the steam used in the vaporization of the aqueous ammonia or its precursor.
  • aqueous urea into a pyrolysis chamber with droplets of under 500 micron, and preferably under 100 micron, will facilitate complete gasification of urea prior to introduction into the exhaust gases and allow close coupling of the pyrolysis chamber and SCR catalyst.
  • the use of a return flow injector is proposed to cool the injector and prevent solids from plugging the injector.
  • the pyrolysis chamber of Peter Hoblyn et al. is described in the specification and shown in the drawings as a small heated chamber with discrete holes disposed in the primary exhaust stream or as a foraminous structure that allows aqueous urea that has been gasified to ammonia in the chamber to escape into the flue gases and flow across a downstream SCR catalyst.
  • Peter-Hoblyn et al. do not describe how to prevent plugging of the compact pyrolysis chamber with urea decomposition products, especially at higher urea injection rates. Additionally, it is difficult to see how complete gasification of urea is accomplished in the pyrolysis chamber described by Peter-Hoblyn et al. While the process of Peter-Hoblyn et al. may work for low urea injection rates on the order of 10-25 grams/minute as required for passenger car diesel engines, it is not apparent how this approach would scale up for higher injection rates of 50-1000 grams/minute or greater, as often required for small stationary combustion sources. [0010] Cho et al., in U.S. Patent No.
  • a heat exchanger in the flue gas to transfer heat to a heat transfer medium, such as ambient air, which is heated to 400 °F - 950 °F and used to vaporize aqueous ammonia that is sprayed with an air assisted injector into a vaporizer vessel and from which vaporized reagent is then injected into the flue gas across a catalyst.
  • a heat transfer medium such as ambient air
  • Cho et al. avoid the need for external electricity or steam for vaporization but do not describe how the temperature in the vaporizer will be maintained at low loads and low flue gas temperatures across the heat exchanger, especially with the cooling effect of the aqueous reagent and atomizing air injected into the vaporizer.
  • Lin et al. teach that a side stream can be generated by bypassing some portion of flue gases around a heat exchanger surface, such as an economizer, into which aqueous urea can be injected and gasified prior to forming a combined stream across a catalyst.
  • a heat exchanger surface such as an economizer
  • Lin et al. describe the bypass flow as less than 10% of the combustion gases. Obviously the overall combustor efficiency would be negatively affected if this large quantity of flue gas were bypassed around a heat exchanger.
  • Lin et al. teach that at high loads with high temperatures the bypass damper can be closed; however, at low loads with low gas temperatures Lin et al.
  • Sun et al. in U.S. Patent Nos. 7,090,810 and 7,829,033, describe a process for reducing NOx from a large-scale combustor involving a side stream of gases or heated ambient air into which urea is injected for decomposition and then introducing the side stream into a primary stream for NOx reduction across a catalyst.
  • Sun et al. specifically teach that residence times of 1 -10 seconds are required to effectively evaporate the water and gasify the urea such that solid byproducts do not foul the distribution pipes, ammonia injection grid (“AIG”) or catalyst or heat transfer surfaces.
  • AIG ammonia injection grid
  • Fuel Tech Inc. has commercially marketed a system called the ULTRATM process which generally uses a burner to decompose large quantities of urea to ammonia for large-scale combustors and a related product called ULTRA-5TM for smaller applications which uses an electric heater to heat ambient air for urea conversion. In many applications, a burner requires an additional permit to operate.
  • the use of ambient temperature atomizing air for the air atomized injector of the Fuel Tech processes can represent as much as 8% of the overall air through the decomposition chamber. That cooler air combined with the cooling effect of introducing aqueous urea into the decomposition chamber can result in an outlet temperature from the decomposition chamber that is under 600 °F and well below the minimum 650 °F - 700 °F outlet temperature range which
  • the present invention provides a means and an apparatus that controls the rate of gas flow through the decomposition duct, maintains temperature in the duct, precisely controls the urea injection rate as a function of boiler load, targets and maintains urea spray quality without additional ambient atomizing air and reduces the residence time requirement for evaporation and gasification to under 1 second while minimizing the need for external power.
  • the present invention is directed to small combustion sources, such as those used in commercial and industrial boiler, furnace and combustion turbine applications generally rated at 10 million to 350 million BTU/hr heat input. It utilizes a blower or fan coupled to the boiler or combustor exhaust from which a slipstream of hot exhaust gas is extracted generally at 300 °F - 750 °F and up to 950 °F. [0018] When the exhaust gas slipstream is above 750 °F, cooling air, water injection or cooler downstream exhaust gas can be added to the slipstream to lower the gas temperature to the blower to less than 750 °F. This reduces the cost of blower materials of construction and improves blower reliability.
  • a supplemental electric heater or burner is disposed in the slip stream portion of a duct following the blower and a temperature sensor is linked to the heater to maintain a gas temperature in the duct before the point of urea injection of at least 750 °F.
  • the sensor is located after the point of injection and used to adjust the heater to maintain at least 650 °F after the injection point.
  • the slip stream portion of the continuous duct leads to an injection portion of the duct followed by a urea decomposition portion of the duct which is typically a simple expanded section of round duct of 4-12” diameter and up to 24-36” diameter depending on the quantity of reagent to be injected.
  • the duct can be insulated to retain heat.
  • a gas swirler can be positioned in the of the injection portion of the continuous duct prior to the urea injection point to create turbulence and mixing of the injected reagent in the gas stream.
  • a smaller diameter slip stream portion of the duct is abruptly expanded into a larger diameter injection portion of the duct to create turbulence, high velocity and mixing past the point of aqueous urea injection.
  • An aqueous solution of 25-50% urea based reagent, or alternatively aqueous ammonia, is sprayed into the injection portion of the duct.
  • a single fluid return flow injector producing an average droplet size of less than 60 microns is used to precisely control the reagent injection rate into the injection portion of the duct as a function of boiler load, exhaust gas flow rate or fuel feed rate which are correlated to uncontrolled boiler NOx emissions.
  • Mapping with a hand held emissions monitor can be used to establish the NOx concentration in the exhaust gas versus combustor load, gas flow rate or fuel feed rate, or sensors can be used to monitor inlet and/or outlet NOx concentration and to adjust the urea injection rate to achieve the NOx reduction required.
  • the urea injection rate into the injection portion of the duct is programmed into a programmable logic controller (PLC) along with a boiler load signal, fuel flow rate, steam flow rate, exhaust gas flow rate, and/or NOx or ammonia slip signal to adjust the injection rate.
  • PLC programmable logic controller
  • the PLC controls the pulse width or on-time of the valve in the solenoid actuated injector which regulates the rate of urea injection.
  • a pumping skid with urea circulation pump, urea pressure sensor, urea filter and optional flow meters is used to circulate urea solution to and from the injector and is controlled by the PLC.
  • a urea day tank with a solenoid valve, level sensor and optional transfer pump can be used to supply urea solution to the injection pump and be automatically controlled by the PLC to refill from bulk storage when the day tank level falls below a set point.
  • urea reagent such as that needed for small combustors can be easily gasified at temperatures of 750 °F and above measured upstream of the urea injection point with residence times of under 1 second if sufficient heated transport air and/or flue gas is available through the urea decomposition duct section to maintain an outlet temperature from the decomposition duct of at least 650 °F and preferably 700 °F and greater.
  • Transport air rates of 150 scfm to 1500 scfm and up to 3000 scfm are generally adequate for decomposition of 0.5-10 gallons/hr of 32% urea in under 1 second residence if the air or flue gas is heated to 750 °F or above prior to the decomposition chamber. Residence time for decomposition is measured from the point of aqueous urea injection in the injection portion of the duct to the point of gasified reagent injection into the primary gas stream upstream of the SCR catalyst.
  • the use of an exhaust gas slipstream as a transport medium helps reduce the cost of supplemental power for a heater or fuel for a burner, although ambient air or preheated air can also be used.
  • An exhaust gas slipstream from a natural gas fired combustor is ideal in that it does not contain particulates from combustion.
  • the exhaust gas slipstream be filtered to reduce particulates through the decomposition duct and ammonia injection grid ("AIG").
  • Ammonia gas that is generated from the urea decomposition in the decomposition portion of the duct is ducted to an ammonia injection grid ("AIG") designed for good distribution of gasified reagent in the primary exhaust gas stream upstream of the SCR catalyst.
  • AIG design is well known to those skilled in the art, and therefore is not set out in detail herein.
  • the AIG can comprise, for example, simple vertical distribution pipes connected by a distribution header to the outlet of the urea decomposition portion of the duct and suspended from the top of a horizontal flowing primary exhaust duct or can comprise horizontal distribution pipes across a vertical flowing primary exhaust duct or other configurations of distribution pipes can be used.
  • Each distribution pipe typically has multiple discharge orifices to achieve good ammonia distribution across the catalyst.
  • a perforated plate or other flow conditioning devices can be installed prior to or downstream of the AIG.
  • Typical slip stream gas flow rates for good distribution through the AIG represent 0.2%-2% of the total exhaust gas flow, although the slip stream of hot carrier gases through the continuous duct can be as high as 10- 50% of the total exhaust on combustion units with high baseline NOx levels requiring high reagent injection rates.
  • FIG. 1 is a schematic cross-sectional view of the present invention.
  • FIG. 2 is a schematic cross-sectional view of a first alternative embodiment of the present invention.
  • FIG. 3 is a schematic cross-sectional view of a second alternative embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION
  • FIG. 1 illustrates a boiler configuration (10) wherein fuel and air are combusted by a burner (28) to form a flame (26) and hot combustion gases (20) which follow an exhaust path (58) past boiler tubes (46) where water through the tubes is converted to steam. Hot exhaust gases continue (60) and exit the boiler through an outlet transition (62). Ambient air (A) is drawn in through a fan (12) and ducted through a cold portion (22) of a continuous duct (14) to an electric heater (25) which heats the ambient air to a temperature of 700 °F - 950 °F.
  • the heated air exiting the electric heater then passes through the hot portion (27) of the continuous duct (14) and through a transition portion (30) of the continuous duct (14) into an injection portion (18) of the continuous duct (14).
  • Injector (36) injects aqueous based urea reagent (32) stored in tank (34) into the injection portion (18) of the continuous duct (14) and flows with the hot carrier gas into the decomposition portion (33) of the continuous duct (14) where the water is evaporated and the reagent is decomposed to ammonia gas.
  • the decomposed and gasified reagent is then ducted to an ammonia injection grid (37) and introduced into the primary exhaust gas (40) through the AIG lances (42) located upstream of catalyst (44).
  • Temperature sensor (35) is used by the controller (56) to control the heater (25) so that the gas temperature in the decomposition portion (33) of the continuous duct (14) after the point of reagent injection is above 600 °F and preferably above 650 °F (i.e., some cooling of the gas, which is supplied to the injection portion (18) of the continuous duct (14) at a temperature of at least 700 °F, may take place due to the injection of the reagent).
  • Pump (54) circulates reagent to injector (36) from storage tank (34) which holds aqueous based reagent (32).
  • Controller (56) controls the pump speed to maintain the pressure of the reagent delivered to the injector (36) and also controls the on time of the injector (36) to regulate the quantity of reagent injected as a function of one or more signals of the boiler load, fuel flow, inlet NOx, outlet NOx, gas flow or ammonia slip past the catalyst.
  • the decomposition portion (33) of the continuous duct (14) is sized to provide a residence time of less than 1 second and more typically between 0.2-0.6 seconds.
  • the continuous duct (14) has a circular cross section and the diameter of the injection portion (18) of the continuous duct (14) is between 0.2 and 2.5 times the diameter of the decomposition portion (33) of the continuous duct (14).
  • the diameters of the injection portion (18) of the continuous duct (14) and the decomposition portion (33) of the continuous duct (14) are the same. It should be noted where the duct is not circular (for example square or rectangular) that the ratio between the injection portion (18) of the continuous duct (14) and the decomposition portion (33) of the continuous duct (14) can also be measured by the cross-sectional area of the ducts.
  • Figure 2 shows an arrangement very similar to that shown in Figure 1 and like reference characters are used to designate like elements. However, the main difference between the embodiment shown in Figure 2 and that shown in Figure 1 is that the ambient air to the fan (12) of Figure 1 is replaced with a hot exhaust gas drawn off from the boiler exhaust via a conduit (70).
  • the exhaust gas temperature at the take off point is between 400 °F and 750 °F as it is delivered to the fan (12), and preferably, the exhaust gas is taken off from the boiler after the heat exchanger section thereof, such that no heat exchanger is bypassed.
  • the electric heater (25) is then used, if necessary, to maintain a temperature of the gases supplied to the injection portion (18) of the continuous duct (14) of at least 700F such that the temperature of the gas flowing in the decomposition portion (33) is at least 650 °F after injection of the reagent.
  • Figure 3 again shows an arrangement very similar to that shown in Figure 1 and like reference characters are used to designate like elements.
  • Example 1 A slipstream of exhaust gas from a lean burn combustion engine is directed to an injection portion of a continuous duct.
  • the slipstream flow rate is 300 scfm at a temperature of 700 °F to 750 °F.
  • the exhaust gas in the primary exhaust and in the slipstream contains 1100 ppm of NOx.
  • the slipstream is connected to an injection portion (18) and a decomposition portion (33) of a continuous duct (14) that is 5” in diameter.
  • aqueous solution of 32.5% urea is injected in the inlet end of the injection portion (18) of the continuous duct (14) using a solenoid actuated return flow injector as described in U.S. Patent No. 7,467,749 to Tarabulski et al., the contents of which is hereby incorporated by reference herein.
  • a computer based TRIM- NOX® injection system as commercially available through Combustion Components Associates Inc. with an injection pump, filter, day tank, pressure sensor and touch screen display is used to inject the aqueous reagent at a rate of 0.5 to 0.75 gallons/hr into the injection duct.
  • the injection portion (18) and the decomposition portion (33) form part of a continuous duct (14), the outlet of which is connected to an ammonia injection grid (AIG) (37).
  • the AIG (37) includes two injection lances (42) that are connected to the outlet of the decomposition portion (33) of the continuous duct (14).
  • the AIG lances (42) have multiple outlet ports to allow ammonia gas to escape from the lances.
  • the AIG lances are fixed in the inlet of a SCR catalyst reactor, upstream of the catalyst (44), such that ammonia gas generated through the decomposition of urea in the decomposition portion (33) of the continuous duct (14) is injected from the lance outlet ports into the flowing stream of the primary exhaust flowing through the catalyst.
  • the catalyst (44) is of a commercial vanadium type formulation on a honeycomb support designed to reduce NOx in the presence of ammonia.
  • NOx out of the catalyst reactor is reduced from 1100 ppm to 100 ppm indicating the decomposition of the aqueous urea to ammonia gas through the decomposition duct is sufficient to reduce NOx in the primary exhaust gas as it passes through the catalyst.
  • Example 2 [0047] A fan is used to supply ambient air to a 60 Kw electric heater. The fan and heater deliver 300 scfm of air at a temperature of 700 °F to 750 °F to a 5” diameter continuous duct having an injection portion (18) and a decomposition portion (33).
  • a 32.5% solution of aqueous urea reagent is injected into the injection portion (18) of the continuous duct (14) using a solenoid actuated return flow injector and system as described in Example 1.
  • the outlet of the decomposition portion (33) of the continuous duct (14) is connected to the AIG (37) and catalyst (44) arrangement as described in Example 1.
  • the full exhaust flow from a lean burn combustion engine is passed through the catalyst reactor at a rate of 1100 scfm to 1200 scfm and a temperature of 750F with a NOx concentration of 1100 ppm.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • General Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Health & Medical Sciences (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Treating Waste Gases (AREA)
  • Exhaust Gas Treatment By Means Of Catalyst (AREA)

Abstract

L'invention concerne un procédé de diminution des émissions de NOx d'une source de combustion à brûlage pauvre, qui utilise une solution aqueuse de réactif injectée dans un conduit de décomposition continue à un débit de 0,2-10 gph avec un flux de gaz chaud côté écoulement à un taux de 150-3000 scfm et une température supérieure à 700°F dans le conduit de décomposition, de sorte que le réactif soit converti en gaz ammoniac qui est transporté par le conduit de décomposition continue vers un réseau d'injection d'ammoniac disposé dans le flux d'évacuation primaire depuis la source de combustion en amont d'un catalyseur de réduction de NOx, réduisant ainsi le NOx.
PCT/US2013/063446 2012-10-05 2013-10-04 Système de réduction catalytique sélective WO2014055858A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201261710356P 2012-10-05 2012-10-05
US61/710,356 2012-10-05
US201314045417A 2013-10-03 2013-10-03
US14/045,417 2013-10-03

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016071537A1 (fr) * 2015-01-20 2016-05-12 Alstom Technology Ltd Agencement d'une chambre de combustion et d'un dispositif pour la réduction non catalytique sélective et procédé d'injection pulsée

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US20040191709A1 (en) * 2003-03-26 2004-09-30 Miller Eric S. Economizer bypass with ammonia injection
US20060115402A1 (en) * 2003-07-03 2006-06-01 Fuel Tech, Inc. SELECTIVE CATALYTIC REDUCTION OF NOx ENABLED BY SIDESTREAM UREA DECOMPOSITION
US20060207243A1 (en) * 2002-05-07 2006-09-21 Phillip Roberts Emission control system
US20080070177A1 (en) * 2006-01-09 2008-03-20 Hansen Eric R METHOD AND APPARATUS FOR REDUCING NOx EMISSIONS IN ROTARY KILNS BY SNCR
US20090274601A1 (en) * 2008-04-30 2009-11-05 Yul Kwan Method of reducing nitrogen oxides in a gas stream with vaporized ammonia
US20100055014A1 (en) * 2000-12-01 2010-03-04 Fuel Tech, Inc. Selective Catalytic Reduction of NOx Enabled by Urea Decomposition Heat-Exchanger Bypass
US20110133127A1 (en) * 2009-11-05 2011-06-09 Johnson Matthey Inc. system and method to gasify aqueous urea into ammonia vapors using secondary flue gases
US20110195007A1 (en) * 2008-05-16 2011-08-11 Postech Academy-Industry Foundation CATALYST FOR REMOVING NOx FROM EXHAUST GAS OF LEAN-BURNING AUTOMOBILES OR INCINERATORS
US20120177553A1 (en) * 2010-12-07 2012-07-12 Lindemann Scott H Injector And Method For Reducing Nox Emissions From Boilers, IC Engines and Combustion Processes

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US20100055014A1 (en) * 2000-12-01 2010-03-04 Fuel Tech, Inc. Selective Catalytic Reduction of NOx Enabled by Urea Decomposition Heat-Exchanger Bypass
US20060207243A1 (en) * 2002-05-07 2006-09-21 Phillip Roberts Emission control system
US20040191709A1 (en) * 2003-03-26 2004-09-30 Miller Eric S. Economizer bypass with ammonia injection
US20060115402A1 (en) * 2003-07-03 2006-06-01 Fuel Tech, Inc. SELECTIVE CATALYTIC REDUCTION OF NOx ENABLED BY SIDESTREAM UREA DECOMPOSITION
US20080070177A1 (en) * 2006-01-09 2008-03-20 Hansen Eric R METHOD AND APPARATUS FOR REDUCING NOx EMISSIONS IN ROTARY KILNS BY SNCR
US20090274601A1 (en) * 2008-04-30 2009-11-05 Yul Kwan Method of reducing nitrogen oxides in a gas stream with vaporized ammonia
US20110195007A1 (en) * 2008-05-16 2011-08-11 Postech Academy-Industry Foundation CATALYST FOR REMOVING NOx FROM EXHAUST GAS OF LEAN-BURNING AUTOMOBILES OR INCINERATORS
US20110133127A1 (en) * 2009-11-05 2011-06-09 Johnson Matthey Inc. system and method to gasify aqueous urea into ammonia vapors using secondary flue gases
US20120177553A1 (en) * 2010-12-07 2012-07-12 Lindemann Scott H Injector And Method For Reducing Nox Emissions From Boilers, IC Engines and Combustion Processes

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2016071537A1 (fr) * 2015-01-20 2016-05-12 Alstom Technology Ltd Agencement d'une chambre de combustion et d'un dispositif pour la réduction non catalytique sélective et procédé d'injection pulsée
EP3047897A1 (fr) * 2015-01-20 2016-07-27 Alstom Technology Ltd Arrangement d'une chambre de combustion pour réduction non catalytique sélective et un procédé d'injection pulsatif
US10724738B2 (en) 2015-01-20 2020-07-28 General Electric Technology Gmbh Arrangement of a combustor and a device for selective non-catalytic reduction and pulsed injection method

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