Urea DeNOx of Diesel Exhaust
http://www.eurekalert.org/pub_releases/2008-11/i-uto111008.php
10-Nov-2008
Contact: Dr. Thomas Hargrove
thargrove@ifdc.org
256-381-6600
Urea tanks on diesel trucks -- that's the law in the United States starting in 2010
Automotive grade of world's most widely used nitrogen fertilizer used to meet new US environmental regulations to cut air pollution
Urea tanks will be standard equipment for most new diesel trucks, buses, cars, and sport utility vehicles (SUVs) manufactured in the United States after Jan. 1, 2010. An automotive grade of urea will be injected into the vehicles' exhaust stream to "scrub" nitrogen oxide (NOx) from the diesel exhaust.
NOx, a major air pollutant, contributes to smog, which causes asthma and respiratory and heart diseases.
The system, urea SCR or "urea-based selective catalytic reduction," is the only technology available that can remove enough NOx from diesel exhaust to comply with strict new limits imposed by the U.S. Environmental Protection Agency (EPA), says Glenn Kedzie, Environmental Counsel for the American Trucking Associations.
The automotive urea, called "diesel exhaust fluid" (DEF) in the United States and AdBlue, a trademarked name in Europe, reduces NOx by as much as 90% alone, and can take NOx to near-zero levels when used in combination with diesel particulate filter technology, says Kim Doran, spokesperson of the newly formed North American SCR Stakeholders Group and editor of FactsAboutSCR.com, a Web site dedicated to SCR news.
DEF and AdBlue are an aqueous urea solution 32 (AUS 32), a clear 32.5% nitrogen solution of high-purity urea in demineralized water. The urea solutions are safe to handle, manufacturers claim. AdBlue can be bought in bulk in Europe or by the liter at some service stations.
The advent of DEF and AdBlue is creating a new demand for urea, the world's most widely used nitrogen fertilizer. Some are concerned that the new use will drive fertilizer prices higher. Others think it will be an incentive for manufacturers to increase production and thus, lower prices.
"We know about diversion of traditional food crops such as corn or sugarcane to biofuels like ethanol — but now urea, a basic input for food production, is also going into fuel," says Dr. Amit Roy, President and CEO of the International Center for Soil Fertility and Agricultural Development (IFDC).
"Ironically, cleaning our environment is a key reason for both technologies."
Manufacturers Adopting Urea SCR Technology
More than half a million diesel trucks in Europe now use urea SCR and the fleet is growing by about 25,000 trucks per month, according to Integer Research, a London-based market analysis firm specializing in urea SCR.
Doran says that SCR technology is being adopted by passenger car and light truck manufacturers serving the United States including Audi, BMW, Hyundai, Jeep, Kia, MiniCooper, and Volkswagen. Mercedes-Benz is introducing three new diesel-powered SUVs that use urea SCR technology into the United States in late 2008. Urea SCR is also used in Japan and Singapore and will soon be used in China.
Manufacturers in the commercial trucking industry adopting SCR include Freightliner, Kenworth, Mack, Peterbilt, and Volvo. Leading engine manufacturers using SCR include Cummins and Detroit Diesel Corp.
Future Demand
Consumption of the urea solution is about 3% of the diesel consumption. Diesel trucks average 6.5 miles per gallon (2.8 km/liter). An average diesel truck will need to refill its 20-gallon tank of DEF every 4,000 to 6,000 miles (76 liters every 6,400 to 9,600 km).
Urea to reduce NOx emissions now consumes 0.3 to 0.4 million metric tons (mt) of urea in Western Europe, says Stephen Zwart, Licensing Manager of Netherlands-based Stamicarbon, the world's largest licensor of urea plant technology. In 10 years the current truck fleet in Western Europe will have been replaced, and urea use will be 3 to 4 million mt.
Future urea demands generated by SCR technology in the United States have been calculated by Dr. Carlos Baanante, IFDC Agricultural Economist.
In 2003, 213 billion liters of diesel fuel were used for transportation in Europe and 146 billion liters in the United States, according to EarthTrends, an initiative of the World Resources Institute (http://earthtrends.wri.org/index.php).
Baanante assumes that only 7% of the diesel trucks in the United States will use urea SCR in 2010 — the new trucks purchased that year.
"U.S. urea consumption for transportation will probably be the urea fertilizer equivalent of about 210,000 tons in 2010 — but will be at least double that amount in 2011 and will increase rapidly afterward as older trucks are replaced with newer models that carry urea tanks," Baanante says.
The estimates assume that a liter of the solution weighs about 1 kg and the urea fertilizer contains 46% N, Baanante explains. Thus, 1 kg of urea solution would consume the N needed to produce 0.7065 kg of urea fertilizer. A conversion factor of 0.7065 is used to calculate urea solution consumption in terms of mt of urea-fertilizer equivalent.
"More than 90% of the world's urea production is for fertilizers — but new demands for urea SCR may change that," Baanante says. Urea is also used in animal feed, plastic and glue manufacture, highway de-icing, cloud seeding to induce rain, and tooth-whitening products.
Stringent New EPA Exhaust Emission Rules
Kedzie says that diesel-powered vehicles manufactured in the United States in 2010 can emit no more than 0.2 grams of NOx per brake horsepower hour — 90% less than current emissions. The new EPA regulations will not apply to vehicles manufactured before 2010.
Tractors, bulldozers, and other non-road vehicles must meet the new EPA standards by 2015. The U.S. timetable for ships and locomotive engines has not yet been set.
"Some trucking agencies are now buying new trucks that were scheduled for replacement after 2010 to avoid the expenses of urea tanks and buying and transporting urea," Kedzie says.
But Thom Albrecht, a transportation equity analyst with Stephens Inc. in Virginia, United States, thinks that most corporate carriers — the main buyers of heavy-duty trucks — will continue normal buying cycles as the next EPA emissions deadline looms in 2010. Albrecht reached that conclusion after surveying 88 carriers about their future buying plans.
New Demands Could Affect World Fertilizer Market
Keith Stokes, proprietor of Stokes Engineering and IFDC consultant on urea production, says, "Urea for NOx reduction will create a new demand that could drive up fertilizer prices—just as ethanol production did."
But Doran of SCR Stakeholders says, "Demand for this automotive-grade urea is not expected to exceed 5% of the world's production. The new use of urea to control vehicle emissions could lead to increased investment and expand world capacity for urea production."
How Urea SCR Systems Work
Urea SCR cleans the exhaust after combustion. The urea solution is held in a separate storage tank and injected as a fine mist into the hot exhaust gases. The heat breaks the urea down into ammonia—the actual NOx-reducing agent. Through a catalytic converter, the ammonia breaks the NOx down to harmless nitrogen (N) gas and water vapor. The exhaust is no longer a pollutant; the atmosphere is about 80% nitrogen gas.
Bill Herz, Vice President of Scientific Programs for The Fertilizer Institute, based in Washington, D.C., says, "You hear a lot about harmful effects of fertilizer on ecosystems—but little about the positive role of urea in stripping away pollutants."
Doran says, "Because SCR technologies reduce NOx exhaust to almost zero, engines can be tuned to maximize fuel efficiency." The result is as much as a 3%??% fuel savings and reduced carbon dioxide emissions.
"The exhaust coming from the tailpipe of an SCR-equipped vehicle may actually be cleaner than the air around it," Doran adds.
In fact, according to Daimler Trucks, the engine efficiency achieved by using SCR technology in Europe has saved customers more than 280 million liters of diesel and nearly half a billion dollars in fuel spending. At the same time, the environment was spared about 800,000 metric tons of carbon dioxide.
A Trucker's Concerns
"We're concerned because we don't know enough about the new urea technology," says Adam Collum, Manager and Co-Owner of Hellums Trucking Co. in Dennis, Mississippi, United States.
"A new heavy-duty diesel truck now costs about $100,000. Adding the urea SCR system will add $10,000 to the cost. How much more will the urea solution that we burn cost? What about maintenance? Will the urea cause corrosion?"
Doran says, "Urea can be corrosive to aluminum. Vehicle SCR systems and DEF dispensers have been designed to accommodate this and DEF is always stored in appropriate containers."
BlueTec Technology in Europe
The new diesel SUVs coming from Daimler in Europe to the United States are called BlueTec models because they are equipped with BlueTec SCR injection systems—a technology that Mercedes-Benz has used in trucks and buses in Europe for years. For these models, the urea will come in cartridges that will be replaced during normal servicing.
Detroit Diesel Corp., a brand of Daimler Trucks North America, has announced that it will use BlueTec technology on all future trucks.
The Mercedes-Benz E320 BlueTec won the 2007 World Green Car of the Year Award partly for "paving the way for super-clean diesel technology around the world." The BlueTec diesel emissions control technology was declared the best new technology for 2007 by the Automotive Journalist Association of Canada.
Planning for the Future
The North American SCR Stakeholders Group met to further plan the development of a distribution and retail infrastructure to ensure DEF availability in the United States in August in Dearborn, Michigan. Stakeholders include representatives of almost 200 organizations including diesel vehicle manufacturers, current and potential DEF producers, fuel and equipment distributors and retailers, as well as the U.S. EPA and Department of Energy, according to an Aug. 11 SCR Stakeholders news release.
Part of the work of the SCR Stakeholders Group involves development of a Web site locator for DEF similar to that used for AdBlue in Europe.
In Europe, AdBlue prices have almost doubled since mid-2007 and producers are finding it difficult to absorb cost increases for urea, Today's Trucking reported on July 18, 2008, citing Integer Research. "Add the fact that producers are getting better returns on urea when it is sold as fertilizer, and no wonder that prices have driven up," the report stated.
DEF Manufacturers
Traditional fertilizer manufacturers will probably produce most DEF urea used in the United States. Producers in the SCR Stakeholders Group include Agrium, Brenntag North America, Dyno Nobel, Koch Industries, Potash Corporation of Saskatchewan, and Terra Industries.
Stephen Zwart of Stamicarbon says, "In Europe, manufacture of AdBlue has been a boon to many fertilizer manufacturers who now allocate part of their production to urea solution for the trucking industry."
Logistics of DEF
Keith Stokes says that delivering urea to gas stations should not be a problem. "Although the United States has more than 30,000 gas stations, only 2,200 of them supply 97% of the heavy-duty vehicle market.
"But urea storage tanks in some regions will need heating coils to keep the solution above its 12° F [-11° C] freezing point."
Pilot Travel Centers, the largest retail operator of travel centers in the United States, announced rollout plans to make DEF available "at the pump" at more than 100 centers in mid to late 2009 in a Sept. 29 news release. The Pilot Centers will also carry prepackaged DEF.
Aqueous Urea Production
Meanwhile, Mitsubishi is increasing production of high-grade aqueous urea solution for urea SCR systems, according to GreenCarCongress.com. The company's plant at Kitakyushu, Japan, has been running at about 20% capacity—about 2 million liters per year. As SCR demand increases, plans are to increase production to 10 million liters in 2008 and reach 50% capacity in 2009.
Japan's demand for high-grade aqueous urea is about 20,000 kiloliters per year, but industry sources expect it to increase to about 600,000 kiloliters in the future.
Need for Higher Production and More Efficient Use of Urea
"The new demands for urea to treat diesel exhausts will make research to improve the efficiency of its use as a fertilizer even more important," says Ramon Lazo de la Vega, IFDC Senior Engineering Specialist. "IFDC works in three main areas to increase the efficiency of urea use: through deep placement of urea briquettes, especially in irrigated rice fields; through controlled-release fertilizers; and through nitrification and urease inhibitors that decrease nitrogen losses to the air through volatization and to groundwater through leaching.
"New urea plants are also being built. For example, two large urea plants are opening in Iran and one each in Egypt, Nigeria, Oman, and Russia."
IFDC's Amit Roy says, "Most basic fertilizer products used today—including major improvements of farm-use urea — were developed by the fertilizer program of the U.S.-based Tennessee Valley Authority (TVA) in the 1950s to 1970s when energy seemed cheap. With current manufacturing technology, the energy equivalent of four barrels of oil is used to convert 'free' atmospheric nitrogen to 1 ton of urea.
"The new demands emphasize the need for research to develop a new range of more energy-efficient technology — not only for food but now for use with fuel," Roy says.
http://www.greencarcongress.com/2007/03/epa_issues_guid.html
30 March 2007
Green Car Congress
EPA Issues Guidance on Urea SCR for Diesel Emissions Control
The EPA has issued guidance on emission certification procedures for on-road diesels that use selective catalyst reduction (SCR) technology for NOx reduction. This guidance enables automakers, for the first time, to adapt the technology to light- and heavy-duty vehicles in the US.
The specific area of concern is the use of a reducing agent (e.g., AdBlue) injected into the exhaust gas upstream of the catalyst. Without the reducing agent, the efficiency of the SCR catalyst drops to zero and NOx emissions can increase substantially. Many automakers, however, are looking to such urea SCR solutions as the near-term solution for meeting Tier 2 Bin 5 emissions regulations for diesels.
The guidance letter is not a ruling — it does not establish a final certification process, but rather reflects the agency’s current thinking and direction.
The letter focuses on specific regulatory requirements that can impact the certification and implementation of SCR for light-duty and heavy-duty diesel vehicles and heavy-duty diesel engines: Allowable Maintenance and Adjustable Parameters.
Allowable maintenance. Under existing regulations, emission-related maintenance can not occur before 100,000 miles of use (150,000 miles for medium- and heavy-duty engines) or before 100,000 mile intervals thereafter. Because the SCR catalyst in a urea SCR system does not function without the use of a reducing agent, EPA believes that the 100,000-mile interval applies to the SCR catalyst and all of the associated hardware, including but not limited to, the reducing agent, the reducing agent storage tank, the dosing valve, and all lines and hoses.
The problem with that from the OEM’s point of view is their inability to equip vehicles with storage tanks of sufficient size to allow for that 100,000-mile interval. The regulatory fix to this is for OEMs to request a change to the scheduled maintenance interval, based on the technological necessity of a new maintenance interval. EPA opened the door for that with the guidance letter, and suggested that “It may be appropriate for EPA to approve an industry-wide scheduled maintenance change, as we have done previously in similar situations.”
Adjustable parameters. Emissions certification testing is done across a range of parameters that can be (a) physically adjusted and (b) affect the emissions outcome. EPA is considering an SCR system that requires a reducing agent to meet the definition of an adjustable parameter—i.e., without the reducing agent, the NOx control fails.
This means that we have the authority to test an SCR-equipped vehicle with varying levels of reducing agent in the storage tank, or, theoretically, without any reducing agent at all. If the vehicle is capable of meeting the NOx standard without any reducing agent, we would not consider the SCR system to be in violation of the standard. However, if the vehicle exceeds emissions standards without reducing agent in the tank, we expect that we would deny the certification because the design will be considered unacceptable. If the manufacturer can prove to EPA that their SCR system design will not run out of reducing agent in-use and thus not exceed the emission standards, we may determine that the design is acceptable and approve certification of the vehicle design.
EPA then divides its acceptance criteria for urea SCR systems into two categories: vehicle compliance and reducing agent availability and accessibility.
Vehicle compliance. There are five different categories for vehicle compliance, and manufacturers must satisfy all five:
1. Driver warning system
2. Driver inducement
3. Identification of incorrect reducing agent
4. Tamper resistant design
5. Durable design
Reducing agent availability. EPA will review each manufacturer’s plan for reducing agent availability and accessibility, with particular emphasis on the following procedures:
1. Reducing Agent Available at Dealerships
2. Reducing Agent Available at Truckstops
3. Back-Up Plan
The EPA also wants to see public eduction plans from each manufacturer. The agency also calls for the establishment of an industry-wide reducing agent quality standard and specifications. SCR systems will need to be designed to operate using the general range of commercially available reducing agents. The agency also notes the importance of having a clear and unambiguous industry-wide identifier, regardless of any brand name.
DaimlerChrysler, with its focus on AdBlue urea SCR systems, was very pleased to have the guidance in hand.
Mercedes-Benz welcomes and supports the EPA’s announcement on Selective Catalytic Reduction (SCR) guidelines, which represent a critical next step for the future acceptance of diesel vehicles in the US market. —Dieter Zetsche, CEO DaimlerChrysler
Mercedes will offer BLUETEC diesel-powered versions of its M-, R- and GL-Class sport- utility vehicles in the United States beginning in CY 2008. The BLUETEC SUVs will use AdBlue injection with SCR.
Resources:
Guidance Letter CISD-07-07 --
http://www.epa.gov/otaq/cert/dearmfr/cisd0707.pdf
PATENTS
Espacenet Advanced Search --
http://ep.espacenet.com/advancedSearch?locale=en_EP
US Patent Office Number Search -- http://patft.uspto.gov/
Hydroxyalkyl-substituted cyclic urea-substituted amines
US5457211
1995-10-10
Fuel compositions containing alkyl-substituted cyclic
urea-substituted amines
US5455358
1995-10-03
Composition of matter for aloyl and aroyl ureas as nitric
oxide reducing agents in diesel emissions
US5292351
1994-03-08
Reduction of nitrogen oxides emissions from diesel engines
US5535708
1996-07-16
Method for reducing the nitrogen oxide concentration in the
exhaust of an internal combustion engine or of a firing system
US5540047
1996-07-30
Reducing NOx emissions from an engine by selective catalytic
reduction utilizing solid reagents
US5809775
1998-09-22
Process for treating nitrogen oxide-containing gas using a
cerium zeolite
US5900222
1999-05-04
Method for utilizing a silencer unit and an arrangement for
applying the method in a large diesel engine
US5832720
1998-11-10
Method for reducing emissions of NOx and particulates from a
diesel engine
US6051040
2000-04-18
Premixing chamber for an exhaust gas purification system
US5943858
1999-08-31
Apparatus for post-treating exhaust gases of an internal
combustion engine
US6843966
2005-01-18
Low emissions diesel fuel
US5746783
1998-05-05
Selective Reduction Catalyst and Engine Exhaust Gas Purifier
Using the Same
US2008317645
2008-12-25
Device for the distribution of flowable additives in exhaust
gas systems
US2008295497
2008-12-04
Dual Injector System For Diesel Emissions Control
US2008087008
2008-04-17
Methods and apparatus for injecting atomized fluid
US2008087739
2008-04-17
Method For Determining NOx Reduction Ratio In Exhaust
Emission Control Devicet
US2007199307
2007-08-30
Exhaust gas-cleaning apparatus
US2007189936
2007-08-16
Method for the post-injection of hydrocarbon-, alcohol-
and/or reducing-agent-type regeneration solution
US2006096274
2006-05-11
Method for the post-injection of hydrocarbon-, alcohol-
and/or reducing-agent-type regeneration solution
US2006096274
2006-05-11
Exhaust gas aftertreatment systems
US2005198942
2005-09-15
BIMODAL CATALYST-UREA SCR SYSTEM FOR ENHANCED NOx CONVERSION
AND DURABILITY
US2005112045
2005-05-26
Exhaust system for enhanced reduction of nitrogen oxides and
particulates from diesel engines
US2005056004
2005-03-17
Device for the dosing of a reducing agent
US2005069468
2005-03-31
Method and device for dosing a reducing agent for the
removal of nitrogen oxides from exhaust gases
US2004047783
2004-03-11
Exhaust cleaning system
US2003221424
2003-12-04
Heater system for diesel engines having a selective
catalytic reduction system
US2004226285
2004-11-18
Exhaust gas aftertreatment systems
US2004098973
2004-05-27
Diesel aftertreatment systems
US2004098971
2004-05-27
Exhaust gas aftertreatment systems
US2004098979
2004-05-27
Exhaust gas treatment unit and measuring instrument for
ascertaining a concentration of a urea-water solution
US2003033799
2003-02-20
Device for exhaust gas after treatment of diesel engines
US2002081239
2002-06-27
Exhaust cleaning system for motor vehicles, especially
diesel-powered utility vehicles
US2002023435
2002-02-28
Structured catalysts for selective reduction of nitrogen
oxides by ammonia using a compound that can be hydrolyzed to
ammonia
US2002025905
2002-02-28
System for NOx reduction in exhaust gases
US6805849
2004-10-19
EXHAUST EMISSION CONTROL DEVICE FOR DIESEL ENGINE
JP2006029172
2006-02-02
EXHAUST GAS TREATING DEVICE FOR ENGINES
JP2005344597
2005-12-15
UREA HYDROLYSIS CATALYST, AMMONIA MANUFACTURING METHOD, AND
DENITRATION METHOD
JP2006122792
2006-05-18
EXHAUST EMISSION CONTROL DEVICE FOR ENGINE
JP2006266192
2006-10-05
SELECTIVE REDUCTION TYPE CATALYST AND EXHAUST GAS PURIFIER
OF ENGINE FOR USE THEREIN
JP2006320854
2006-11-30
MEASURING INSTRUMENT OF NH3 AND NOx IN EXHAUST GAS
JP2007051924
2007-03-01
EXHAUST EMISSION CONTROL DEVICE
JP2007023997
2007-02-01
EXHAUST EMISSION CONTROL DEVICE FOR ENGINE
JP2007113401
2007-05-10
EXHAUST TREATMENT DEVICE
JP2008057520
2008-03-13
Improvements in engine emissions
GB2414692
2005-12-07
Reductant injection controlled by engine acceleration
GB2396834
2004-07-07
Controlling reductant injection in response to engine
behaviour
GB2397036
2004-07-14
Exhaust flow switching valve incorporating reductant
injection
GB2393140
2004-03-24
Fuel additive composition for the reduction of emissions
from IC engines
GB2361932
2001-11-07
Improvements in catalytic reduction of NOx
GB2361653
2001-10-31
Exhaust Treatment System with Catalyzed Coating on the Inner
Wall of the Exhaust Pipet
GB2452613
2009-03-11
Multi-stage regeneration of a particulate filter
GB2452383
2009-03-04
An exhaust system
GB2452249
2009-03-04
Discharge and carbamide box reactor of crude oil automobile
CN201162561
2008-12-10
Exhaust gas purifier for diesel engine
CN101283169
2008-10-08
Diesel automobile exhaust and urea box reflector
CN101240729
2008-08-13
Technique for preparing ammonia from urea by pyrolysis
methodt
CN101125666
2008-02-20
Exhaust system for use in e.g. diesel engine
DE102007002664
2008-07-24
Liquid reducing agent e.g. aqueous urea solution, dosing
device for e.g. diesel-operated internal combustion engine
DE102006061734
2008-07-03
Car e.g. diesel car partly filled by a urea tank
DE102006059991
2008-06-26
Exhaust gas emission control device i.e. selective catalytic
reduction system, for e.g. diesel engine
DE102007047906
2008-06-05
Exhaust gas catalytic denitrification for quantitative
nitrogen oxide removal
DE4221451
1994-01-05
Denitrogenating exhaust gases from diesel and lean-mix
engines
DE4446773
1996-06-27
Device for dosing a reducing agent, especially urea or a
urea-water solution
DE10127834
2002-12-12
Device for treating diesel engine exhaust gases comprises
storage tank for urea-water solution, and air line which opens
into tank
DE10319841
2004-12-02
Membrane pump used for conveying a medium for treating
exhaust gases in diesel engines
DE10351222
2005-06-02
Exhaust gas cleaning system especially for diesel engine
DE10348492
2005-05-25
Commercial vehicle liquid urea tank
DE20315807
2003-12-11
Polymer hose for urea-water solution circuits e.g. diesel
exhaust cleaning system
DE202004018697
2005-02-03
System for dosing a urea-water solution into the exhaust gas
tract of a vehicle having a diesel engine
DE102004048076
2006-04-06
Atomization mechanism for treatment of exhaust gases of
diesel engines with treatment medium consisting of urea and
water
DE102004035119
2006-02-16
Mounting part for e.g. diesel engine of motor vehicle
DE102005063081
2007-07-05
Catalytic selective reduction system with urea promotion,
for diesel engine exhaust gas
DE102006049591
2007-05-31
Exhaust gas after treatment device for e.g. diesel engine
DE102005041733
2007-03-08
Sensor for a liquid urea solution, for reduction of nitrogen
oxide in a diesel motor exhaust gas
DE102007003860
2007-08-02
Exhaust gas treatment device for use in e.g. diesel motor
vehicle
DE102007004296
2008-04-17
Reducing agent e.g. urea solution, dosing system for e.g.
diesel engine
DE102006040411
2008-03-06
ADDITIVE FOR IMPROVING THE PERFORMANCE OF NITROGEN OXIDE
REDUCING SYSTEMS BY UREA OF THE EXHAUST GASES OF DIESEL
ENGINES
WO2008129203
2008-10-30
NOZZLE AND METHOD FOR ATOMIZATION OF FLUIDS
WO2008058548
2008-05-22
DEVICE FOR METERING REDUCING AGENT AND INJECTOR IN A DEVICE
FOR METERING REDUCING AGENT
WO2008058635
2008-05-22
DEVICE FOR METERING REDUCING AGENT AND INJECTOR IN A DEVICE
FOR METERING REDUCING AGENT
WO2008058634
2008-05-22
SYSTEM AND METHOD FOR NOx REDUCTION OPTIMIZATION
WO2007084691
2007-07-26
DEVICE, REACTOR AND METHOD FOR REDUCING NITROGEN OXIDES IN
THE EXHAUST FLOW OF INTERNAL COMBUSTION ENGINES
WO2007022926
2007-03-01
METHOD FOR PRODUCING UREA PELLETS
WO2007017159
2007-02-15
DEVICE FOR DOSING A REDUCING AGENTS
WO2007017044
2007-02-15
METHOD FOR EXHAUST GAS TREATMENT FOR DIESEL ENGINES
WO2006092190
2006-09-08
EXHAUST GAS PURIFICATION DEVICE FOR INTERNAL COMBUSTION
ENGINE
WO2006057305
2006-06-01
FROST-RESISTANT LIQUID PRESSURE SENSOR FOR EXHAUST REDUCING
SYSTEMS (DIESEL ENGINE)
WO2005029029
2005-03-31
DEVICE FOR DOSING A REDUCING AGENT
WO0225074
2002-03-28
TANK FOR A VEHICLE WITH A REDUCTION-AGENT-OPERATED EXHAUST
FUME PURIFICATION SYSTEM
WO9902825
1999-01-21
REDUCING NOx EMISSIONS FROM AN ENGINE WHILE MAXIMIZING FUEL
ECONOMY
WO9845581
1998-10-15
METHOD AND APPARATUS FOR REDUCING HARMFUL EMISSIONS FROM A
LEAN-BURN ENGINE BY UREA INJECTION
WO9828070
1998-07-02
METHOD AND APPARATUS FOR REDUCING HARMFUL EMISSIONS FROM A
DIESEL ENGINE BY UREA INJECTION
WO9736676
1997-10-09
PRE-MIXING CHAMBER FOR AN EXHAUST GAS CLEANING UNIT
WO9636797
1996-11-21
THE REDUCTION OF NITROGEN OXIDES EMISSIONS FROM DIESEL
ENGINES
WO9506805
1995-03-09
METHOD FOR REDUCING EMISSIONS OF NOx AND PARTICULATES FROM A
DIESEL ENGINE
WO9502655
1995-01-26
PROCESS AND DEVICE FOR CONTROLLABLY ADDING A REDUCING AGENT
INTO NITROGEN OXIDE-CONTAINING EXHAUST GAS
WO9427035
1994-11-24
Module and method for introducing a urea solution into the
exhaust gas of an engine
EP1712753
2006-10-18
Method and device for supply of additive for exhaust gas
cleaning
EP1698769
2006-09-06
System and method for injecting a liquid into a gas stream,
exhaust gas treatment device and vehicle incorporating said
device
EP1612381
2006-01-04
Exhaust gas aftertreatment device
EP1553270
2005-07-13
Vehicle with a special arrangement of a fuel tank, a
secondary muffler and a reduction agent tank
EP1503055
2005-02-02
Dispensing column for urea solution
EP1460031
2004-09-22
Device for exhaust gas treatment of vehicle, especially for
diesel engine vehicle
EP1380733
2004-01-14
Process for cleaning a spray nozzle for a urea solution used
for the catalytic reduction of exhaust gases
EP1366802
2003-12-03
Exhaust gas treating apparatus with silencer for a diesel
engine
EP1357267
2003-10-29
Process and installation for purification of exhaust gases
from internal combustion engines
EP1095692
2001-05-02
Process and device for metering a reducing agent
EP1022048
2000-07-26
Static mixer and exhaust duct for a combustion system
EP0894523
1999-02-03
Injection arrangement for an internal combustion engine
EP0718489
1996-06-26
DENITRIFICATION CATALYST, HONEYCOMB STRUCTURE TYPE
DENITRIFICATION CATALYST
EP1967264
2008-09-10
Urea tank for transport vehicle, unit comprising a diesel
tank and said urea tank
EP1956207
2008-08-13
Catalytic converter for reducing nitrogen oxide content in
exhaust gases of an internal combustion engine
EP0617199
1994-09-28
Method and device for reducing nitrogen oxide emissions from
internal combustion engines
EP0527362
1993-02-17
Device for treating exhaust gas from a diesel engine
FR2843612
2004-02-20
Internal combustion engine has exhaust gas cleaner that
generates fuel with the aid of hydrogen
FR2839340
2003-11-07
Sensor for a liquid urea solution, for reduction of nitrogen
oxide in a diesel motor exhaust gas
FR2896587
2007-07-27
HEATING DEVICE FOR UREA RESERVOIR TANK OF DIESEL ENGINE
KR20070059641
2007-06-12
AN APPARATUS FOR UREA SUPPLY IN REDUCTION OF NOX IN DIESEL
ENGINE
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