WO2000030733A1 - Liquid urea exhaust gas treatment additive - Google Patents

Liquid urea exhaust gas treatment additive

Info

Publication number
WO2000030733A1
WO2000030733A1 PCT/US1999/027819 US9927819W WO0030733A1 WO 2000030733 A1 WO2000030733 A1 WO 2000030733A1 US 9927819 W US9927819 W US 9927819W WO 0030733 A1 WO0030733 A1 WO 0030733A1
Authority
WO
Grant status
Application
Patent type
Prior art keywords
treatment
urea
additive
weight
exhaust
Prior art date
Application number
PCT/US1999/027819
Other languages
French (fr)
Inventor
Richard W. Grosser
Original Assignee
Mobil Oil Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date

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Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N3/00Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
    • F01N3/08Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
    • F01N3/10Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
    • F01N3/18Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control
    • F01N3/20Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by methods of operation; Control specially adapted for catalytic conversion ; Methods of operation or control of catalytic converters
    • F01N3/2066Selective catalytic reduction [SCR]
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/46Removing components of defined structure
    • B01D53/54Nitrogen compounds
    • B01D53/56Nitrogen oxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/92Chemical or biological purification of waste gases of engine exhaust gases
    • B01D53/94Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
    • B01D53/9404Removing only nitrogen compounds
    • B01D53/9409Nitrogen oxides
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01JCHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J12/00Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor
    • B01J12/007Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor in the presence of catalytically active bodies, e.g. porous plates
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2610/00Adding substances to exhaust gases
    • F01N2610/02Adding substances to exhaust gases the substance being ammonia or urea
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23JREMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
    • F23J2215/00Preventing emissions
    • F23J2215/10Nitrogen; Compounds thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23JREMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
    • F23J2219/00Treatment devices
    • F23J2219/10Catalytic reduction devices
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02ATECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
    • Y02A50/00TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection
    • Y02A50/20Air quality improvement or preservation
    • Y02A50/23Emission reduction or control
    • Y02A50/232Catalytic converters
    • Y02A50/2322Catalytic converters for exhaust after-treatment of internal combustion engines in vehicles
    • Y02A50/2325Selective Catalytic Reactors [SCR]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02TCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00Road transport of goods or passengers
    • Y02T10/10Internal combustion engine [ICE] based vehicles
    • Y02T10/20Exhaust after-treatment
    • Y02T10/24Selective Catalytic Reactors for reduction in oxygen rich atmosphere

Abstract

Methods for the treatment of combustion effluent containing nitrogen oxides are provided. According to these methods, the combustion effluent is treated with a liquid treatment additive composition comprising urea, water and an oxygenated organic compound, in the presence of a catalyst. The treatment additive compositions of the present invention have lower freezing points than water/urea solutions, which allows use and storage of the treatment additive at temperatures below 10 °F (-12 °C), if necessary.

Description

LIQUID UREA EXHAUST GAS TREATMENT ADDITIVE

This application relates to, and claims priority from, U.S. provisional patent application serial No. 60/109,428, filed on November 23, 1998. U.S. Application Serial No. 09/ , filed concurrently (Mobil Case

10088-1), relates to a vehicle engine additive dispenser system.

The present invention is directed to a method for treating combustion effluent for removal of nitrogen oxides using liquid compositions of urea. Additives are present in the compositions to impart properties that make the compositions particularly useful at low temperatures and in the treatment of motor vehicle exhausts.

The burning of hydrocarbon fuels in internal combustion engines results in the production and release of a mixture of combustion products. The major combustion products are carbon dioxide and water, both of which are usually accompanied by minor amounts of carbon monoxide (CO), nitrogen oxides (NO2), and sulfur oxides (SO2). Oxides of nitrogen and sulfur have been implicated in the formation of smog, acid rain, and other atmospheric problems and are therefore considered to be undesirable pollutants. Various measures have been taken in the recent past to regulate the amount of these pollutants emitted from motor vehicles. While reduction of the amount of sulfur in fuels has led to lowered SO2 emissions, the lowering of nitrogen oxide content in vehicle emissions cannot be treated similarly. Advances in the design of engines as well as alterations in the composition of fuels may mitigate the production of nitrogen oxides; however, the combustion of air/fuel mixtures will always have the undesirable side effect of producing NO2 emissions.

Due to the persistent problem of NO2 emission from combustion processes, the most effective strategy for reducing amounts of polluting nitrogen oxides involves the treatment of post-combustion emissions. To date, this strategy has been primarily applied to stationary industrial processes including furnaces, boilers, and stationary diesel engine applications. One method employed for the removal of NO2 contaminants involves the treatment of combustion emissions with ammonia. In this method, ammonia selectively reacts with NO2 to give the innocuous reduction products of diatomic nitrogen (N2) and water. When the reaction occurs by free radical formation and recombination at high temperatures, it has been termed selective non-catalytic reduction (SNCR). When the reaction occurs in the presence of a catalyst, it is termed selective catalytic reduction (SCR). SCR-type processes for reducing NO2 emissions have been favored over SNCR-type processes because of higher N02 removal efficiencies, lower ammonia consumption, and the production of fewer side products. However SCR treatments are more sensitive to the ratio of ammonia to NO2. Thus, SCR has been adapted primarily for the treatment of NO2- containing effluents of large scale, stationary, industrial processes which emit relatively constant quantities of NO2. However recent advances in the precise dosing of liquid reagents has made possible the application of SCR to the treatment of effluents from devices, such as motor vehicles, with variable effluent compositions. The ammonia used in an SCR process can also be generated in situ by thermal decomposition and hydrolysis of urea at high temperatures. Unlike ammonia, urea is a safe and tractable starting material, and can be used either as a solid or in solution. Several methods have been disclosed that utilize urea for the reduction of N02 emissions. U.S. Patent Nos. 4,208,386 and 4,325,924 describe the use of hydroxylic solutions of urea in the treatment of combustion effluent in noncatalytic treatment systems at sustained temperatures above 1300°F (705°C). U.S. Patent Nos. 4,719,092, 4,780,289, 4,978,514, 5,057,293, 5,286,467, and 5,298,230 reveal processes for the treatment of industrial combustion effluents using aqueous urea compositions containing additives which chemically enhance effectiveness. Despite the multitude of industrial applications for urea compositions in the treatment of NO2 emissions, the above-mentioned urea compositions have not been designed for specifically maintaining liquidity at low temperatures so that they may remain useful under a wide range of climatic conditions. In addition, the known compositions are not directed for use in smaller, mobile applications, such as for the treatment of exhaust from motor vehicles.

Factors specific to mobile combustion engines must be considered in the design of potential exhaust treatment systems. First, the system must be composed of materials and components that are compact and light weight for maintaining efficiency and performance of the vehicle. Also, the system should be relatively easy to use, even by the unskilled user. In accordance, the materials of the system should also be capable of replenishment with a minimum amount of trouble and cost to the user as well as have safe-handling properties. In addition, the materials need to be easily manipulated, such as with a liquid, which can be readily stored, pumped, and discharged on a moving vehicle. Furthermore, the materials should retain these desirable properties over a range of typical vehicle storage and operating temperatures.

Of particular importance for liquid exhaust treatments is the prevention of liquid phase changes at the low temperatures usually encountered by vehicle users in the colder climatic regions. Freezing is a particular problem of aqueous-based solutions thus creating a need for liquid exhaust treatments that will maintain the liquid state down to storage temperatures of -20°F ( -30°C). In consideration of the potential application of SCR methods for the lowering of nitrogen oxide emissions in motor vehicle exhaust, specific urea formulations that will resist freezing at low temperatures are potentially important contributions to future reduction in air pollution.

The present invention relates to methods for treating combustion effluent containing nitrogen oxides. These methods involve treating the combustion effluent with a treatment additive in the presence of a catalyst. Preferable applications of the methods of the present invention are directed to the treatment of exhaust from motor vehicles, particularly those with diesel engines. The treatment additive comprises water and urea. A preferred treatment additive further comprises at least one oxygenated organic compound (or oxygen-containing organic compound) which is miscible with the aqueous urea solution. A preferred oxygenated organic compound is an alcohol. Applicant has discovered that the novel compositions of the present invention allow use and storage of the treatment additive at commonly encountered climatic conditions. Suitable alcohols include, but are not limited to, monohydric and polyhydric alcohols.

As used in this specification, the terms "fuel additive," "treatment agent" and "treatment additive" are used interchangeably and mean, collectively, a substance that is either added to fuel or employed to treat effluent derived from the combustion of fuel. A preferred "treatment additive" is an aqueous solution of urea and, optionally, an oxygenated organic compound (or oxygen-containing organic compound). An oxygenated organic compound includes an organic compound containing at least one oxygen atom. According to the present invention, an oxygenated organic compound includes, but is not limited to, alcohols, ethers, esters, aldehydes, ketones and carboxylic acids. Furthermore, an oxygenated organic compound may include any substance having effective use in the treatment of gasoline and combustion processes.

As used in this specification, the term "combustion effluent" refers collectively to the products of the combustion of hydrocarbons in the presence of air which include carbon dioxide, water, hydrocarbons, carbon monoxide, sulfur oxides, and nitrogen oxides. The term "exhaust" is used to describe the combustion effluent emitted from motor vehicles. In addition, the term "reaction zone" refers to a device, means or location where combustion effluent and the urea composition are combined, the reaction zone usually containing one or more catalysts suitable for effecting hydrolysis of urea and SCR in a motor vehicle. A preferred reaction zone is an exhaust pipe of a motor vehicle. The exhaust pipe of a motor vehicle is a tube or pipe that connects the engine of the vehicle to the selective catalytic reduction (SCR) unit of the vehicle.

The term "nitrogen oxides" or "NO2" refers collectively to both nitric oxide (NO) and nitrogen dioxide (NO2). Hence, the term "NO2 emissions" or "nitrogen oxide emissions" refers to NO2 found in combustion effluent.

Alcohols are preferred oxygenated organic compounds. As used herein, the term "alcohol" means a chemical compound with at least one hydroxyl group that also possesses properties desirable for the present invention. "Alcohol" or "alcohols" include, but are not limited to, polyhydric alcohols (i.e., compounds with more than one hydroxyl group, such as ethylene glycol, propylene glycol, glycerol, polyethylene glycol and polyoxyalcolamine glycol) and monohydric alcohols (i.e., compounds with only one hydroxyl group, such as in methanol, ethanol, propanol, and isopropanol).

The present invention provides methods for treating combustion effluent containing nitrogen oxides (NO2). In particular, the present invention relates to methods for reducing NO2 emissions from combustion devices using a liquid treatment additive comprising urea, water and an oxygenated organic compound. A preferred oxygenated organic compound comprises an alcohol. Treatable combustion effluent may be derived from any mobile combustion device including, but not limited to, combustion engines including both spark-ignited and diesel. Specifically, the methods of the present invention are particularly suited for treatment of exhaust from combustion engines in motor vehicles including, but not limited to, cars, trucks, tractors, farm equipment, construction equipment, and the like. The methods of the present invention preferably treat exhaust from motor vehicles operating with diesel engines which generally have higher NO2 emissions.

According to the present invention, a liquid treatment additive comprising urea is combined with combustion effluent in a reaction zone before the effluent is released to the atmosphere. The treatment additive is stored in a storage container and may be added to the effluent by injection or spray. Preferably, the amount of treatment additive added is such that a maximum amount of NO2 is reacted to form N2 and water, and a minimum amount of byproducts, such as excess ammonia, are created. Preferably, the molar ratio of urea to NO2 ranges from 0.1 :1 to 1 :1 , or more preferably, is stoichiometric at 1 :2. Elevated temperatures are also required in the reaction zone for both the decomposition of urea and the reaction of ammonia with NO2. Effluent entering the reaction zone may range in temperature from ambient temperature to 1000°F (540°C). The reaction zone also contains one or more catalysts that can be of any known material or combination of materials used in the hydrolysis of urea or SCR reactions such as transition metals, or metal oxides. Specific catalysts (or SCR catalysts) include, but are not limited to, metal oxides, transition metal oxides, transition metals, precious metals, vanadium oxide, tungsten oxide, titanium oxide, iron oxide, manganese oxide, chromium oxide, copper oxide, zeolites, platinum, palladium, rhodium, and iridium. Catalyst materials are preferably mounted on supports composed of ceramics or zeolites.

In a preferred embodiment of the present invention, a treatment additive comprising urea is added to motor vehicle exhaust in a reaction zone prior to release of the exhaust to the atmosphere. Exhaust, requiring treatment, typically contains NO2 in the range of 100 ppm to 1100 ppm. The treatment additive is added to the exhaust in amounts and molar ratios as described above. Prevailing temperatures in motor vehicle exhaust are sufficiently elevated to promote both the decomposition of urea to ammonia and the reaction of the resulting ammonia with N02 in the presence of any of the aforementioned catalysts or combination of catalysts. Exhaust temperatures in the reaction zone may range from ambient temperature to 1000°F(540°C). Treated exhaust has lowered NO2 content which has been reduced by 30% to 99%, or more preferably, by 50% to 99%.

Preferred treatment additives according to the methods of the present invention include liquid compositions comprising water and urea. In a preferred embodiment the treatment additive further comprises at least one oxygenated organic compound. In one embodiment the treatment additive comprises at least two oxygenated organic compounds. In other embodiments, the treatment additive comprises three or more oxygenated organic compounds. Preferred oxygenated organic compounds include alcohols. Alcohols according to the present invention include, but are not limited to, monohydric and polyhydric alcohols that are miscible with water and form aqueous solutions with a freezing point lower than that of water. Polyhydric alcohols are preferred. Examples of suitable polyhydric alcohols include, but are not limited to, ethylene glycol, propylene glycol, glycerol, polyethylene glycol, and polyoxyalcolamine glycol. A preferred polyhydric alcohol is ethylene glycol.

Monohydric alcohols are also amenable to the methods of the present invention.

Monohydric alcohols which may be suitable according to the methods of the present invention include, but are not limited to, methanol, ethanol, propanol, and isopropanol.

The treatment additive may further comprise other agents including, but not limited to, demineralizers and dyes. Demineralizers may be added to prevent scaling, which would decrease the efficiency of the methods of the claimed invention. Dyes may also be added to the treatment additive or to potentially toxic components such as the alcohol of the treatment additive to ensure safe handling.

The amounts of each component in the treatment additive compositions are determined by the intended application of the present invention. Generally, however, it is favorable to maximize the relative amount of urea in the composition so that a minimal volume of treatment additive may be used to effectively treat nitrogen oxide- containing effluents. Similarly, it is desirable to include an oxygenated organic compound in an amount that is sufficient to obtain a target freezing point. Target freezing points of the liquid compositions preferably lie below the freezing point of a urea/water solution (for example, 10°F or -13°C for a 30% urea solution by weight), although below -15°F (-26°C) is more preferable, and at or lower than -20°F (-29°C) is even more preferable. Furthermore, it is desirable to include water in the composition in an amount that is sufficient to maintain urea in solution. In a preferred embodiment, the treatment additive composition comprises 30% to 70% by weight of water, 20% to 40% by weight of urea, and 1 % to 40% by weight of an oxygenated organic compound. More preferable treatment additive compositions comprise 35% to 45% by weight of water, 25% to 35% by weight of urea, and 25% to 35% by weight of an oxygenated organic compound. In another preferred embodiment, the treatment additive composition comprises 40% by weight of water, 30% by weight of urea, and 30% by weight of an oxygenated organic compound. A preferred oxygenated organic compound is ethylene glycol. The treatment additive compositions of the present invention can be stored and used over a wide range of temperatures. These compositions store particularly well at low temperatures because they possess lower freezing points than water/urea solutions, enabling them to remain in the liquid state when temperatures may regularly or occasionally fall below the freezing point of a urea/water solution (for example, 10°F or -13°C for a 30% urea solution by weight). Because of this property, the treatment additive compositions of the present invention are particularly useful in applications where combustion devices operate in temperatures below 10°F (-13°C).

EXAMPLES Example 1

A urea blend suitable for use in the treatment of vehicle exhaust

An aqueous solution containing 40% water by weight, 30% urea by weight, and 30% ethylene glycol by weight was formulated. The freezing point of the solution was determined to be -20°F(-29°C) at which point the liquid turned to slush.

Example 2

A urea blend suitable for use in the treatment of vehicle exhaust

An aqueous solution containing 50% water by weight, 30% urea by weight, and 20% ethylene glycol by weight was formulated. The blend remained clear and fluid at -15°F (-26°C).

Example 3

Treatment of exhaust from a diesel vehicle with a liquid urea composition

Exhaust evolving from a motor vehicle diesel engine contains 4 g/mile average amount of NO2 and has an average temperature of 400°F. An amount of 13 g/mile of solution containing 40% water by weight, 30% urea by weight, and 30% ethylene glycol by weight is added to the exhaust by a spray means. The exhaust and spray mixture is passed over a zeolite catalyst where NO2 is reacted. Treated exhaust exits the vehicle with an NO2 content of 0.4 g/mile (0.25 g. km."1)showing an overall reduction of 3.6 g/mile (2.2 g. km."1) of NO2 in exhaust emissions, which is similar to exhaust treated with an aqueous urea solution lacking an oxygenated organic compound.

Claims

CLAIMS:
1. A method of treating exhaust from a motor vehicle, the exhaust containing nitrogen oxides, the method comprising adding a treatment additive comprising water and urea to the exhaust.
2. The method of claim 1 in which the treatment additive further comprises at least one oxygenated organic compound.
3. The method of claim 1 in which the motor vehicle is operated with a diesel engine.
4. The method of claim 1 further comprising adding the treatment additive to the exhaust in the presence of an SCR catalyst.
5. The method of claim 2 in which the oxygenated organic compound is an alcohol.
6. The method of claim 5 in which the alcohol is ethylene glycol, propylene glycol, polyethylene glycol, glycerol or polyoxyalcolamine glycol.
7. The method of claim 5 in which the alcohol is methanol, ethanol, propanol or isopropanol.
8. The method of claim 2 in which the treatment additive comprises 30% to 70% by weight of water, 20% to 40% by weight of urea, and 1 % to 40% by weight of oxygenated organic compound.
9. The method of claim 8 in which the treatment additive comprises 35% to 45% by weight of water, 25% to 35% by weight of urea, and 25% to 35% by weight of ethylene glycol.
10. The method of claim 15 in which the treatment additive comprises 40% by weight of water, 30% by weight of urea, and 30% by weight of ethylene glycol.
11. A diesel engine exhaust treatment additive comprising 30% to 70% by weight of water, 20% to 40% by weight of urea, and 1 % to 40% by weight of oxygenated organic compound.
12. The treatment additive of claim 11 comprising 35% to 45% by weight of water, 25% to 35% by weight of urea, and 25% to 35% by weight of oxygenated organic compound.
13. The treatment additive of claim12 comprising 40% by weight of water, 30% by weight of urea, and 30% by weight of oxygenated organic compound.
14. The treatment additive of claim 23 in which the oxygenated organic compound is ethylene glycol.
15. The treatment additive of claim 11 in which the alcohol is ethylene glycol, propylene glycol, polyethylene glycol, glycerol or polyoxyalcolamine glycol.
16. The treatment additive of claim 11 in which the alcohol is methanol, ethanol, propanol or isopropanol
PCT/US1999/027819 1998-11-23 1999-11-23 Liquid urea exhaust gas treatment additive WO2000030733A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
US10942898 true 1998-11-23 1998-11-23
US60/109,428 1998-11-23

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP19990965882 EP1140327A1 (en) 1998-11-23 1999-11-23 Liquid urea exhaust gas treatment additive
JP2000583610A JP2002530575A (en) 1998-11-23 1999-11-23 Exhaust gas treatment liquid urea additive

Publications (1)

Publication Number Publication Date
WO2000030733A1 true true WO2000030733A1 (en) 2000-06-02

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Country Status (3)

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EP (1) EP1140327A1 (en)
JP (1) JP2002530575A (en)
WO (1) WO2000030733A1 (en)

Cited By (7)

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WO2003039718A1 (en) * 2001-11-06 2003-05-15 Robert Bosch Gmbh Method and device for reducing nitrogen oxides present in exhaust gases
FR2843612A1 (en) * 2002-08-14 2004-02-20 Bosch Gmbh Robert Device for treating exhaust gas from a diesel engine comprises a storage unit for storing an aqueous urea solution having an additive for chemically influencing the solution
WO2004042208A1 (en) * 2002-11-06 2004-05-21 Robert Bosch Gmbh Device for the secondary treatment of the exhaust gas of an internal combustion engine
WO2010044676A1 (en) * 2008-10-14 2010-04-22 Yara International Asa Method for minimizing the diameter of droplets of a urea solution by use of a surfactant mixture of alkoxylated compounds
CN102397749A (en) * 2010-09-11 2012-04-04 中国第一汽车集团公司 Composition of urea reducing agent capable of improving atomization effect
US8615985B2 (en) 2006-10-02 2013-12-31 EMITEC Gesellschaft fuer Emissions Technologies mbH Method and device for providing a gas flow containing a reducing agent
WO2016012532A1 (en) 2014-07-25 2016-01-28 Ambiente E Nutrizione S.R.L. Process for the modification of the surface charge

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JP5243705B2 (en) * 2006-08-24 2013-07-24 三井化学株式会社 Internal combustion engine exhaust treatment for NOx reducing agent
JP2009035644A (en) * 2007-08-02 2009-02-19 Denso Corp Antifreeze urea solution for urea selective catalytic reduction (scr) system and urea scr system
KR101589078B1 (en) * 2013-08-30 2016-01-27 이광춘 Manufacturing method of Additive to prevent freezing of Urea and Additive to prevent freezing of Urea manufactured by the same
JP2017145709A (en) * 2016-02-15 2017-08-24 株式会社デンソー Exhaust emission control system

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Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2003039718A1 (en) * 2001-11-06 2003-05-15 Robert Bosch Gmbh Method and device for reducing nitrogen oxides present in exhaust gases
FR2843612A1 (en) * 2002-08-14 2004-02-20 Bosch Gmbh Robert Device for treating exhaust gas from a diesel engine comprises a storage unit for storing an aqueous urea solution having an additive for chemically influencing the solution
GB2394192A (en) * 2002-08-14 2004-04-21 Bosch Gmbh Robert Urea solution storage for exhaust gas treatment
GB2394192B (en) * 2002-08-14 2004-11-24 Bosch Gmbh Robert Device for treating the exhaust gas from a combustion apparatus
US7100367B2 (en) 2002-08-14 2006-09-05 Robert Bosch Gmbh Device for exhaust gas treatment of a combustion system
WO2004042208A1 (en) * 2002-11-06 2004-05-21 Robert Bosch Gmbh Device for the secondary treatment of the exhaust gas of an internal combustion engine
US7449162B2 (en) 2002-11-06 2008-11-11 Robert Bosch Gmbh Device for treatment of exhaust of an internal combustion engine
US8615985B2 (en) 2006-10-02 2013-12-31 EMITEC Gesellschaft fuer Emissions Technologies mbH Method and device for providing a gas flow containing a reducing agent
WO2010044676A1 (en) * 2008-10-14 2010-04-22 Yara International Asa Method for minimizing the diameter of droplets of a urea solution by use of a surfactant mixture of alkoxylated compounds
CN102176956B (en) 2008-10-14 2013-11-06 亚拉国际有限公司 Method for minimizing the diameter of droplets of a urea solution by use of a surfactant mixture of alkoxylated compounds
US9050560B2 (en) 2008-10-14 2015-06-09 Yara International Asa Method for minimizing the diameter of a urea solution, urea solution and use of a surfactant in urea solution
CN102397749A (en) * 2010-09-11 2012-04-04 中国第一汽车集团公司 Composition of urea reducing agent capable of improving atomization effect
WO2016012532A1 (en) 2014-07-25 2016-01-28 Ambiente E Nutrizione S.R.L. Process for the modification of the surface charge

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Publication number Publication date Type
EP1140327A1 (en) 2001-10-10 application
EP1140327A4 (en) 2001-10-10 application
JP2002530575A (en) 2002-09-17 application

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