Integrated Fuel Technologies Licenses Argonne-developed Diesel DeNOx Catalyst; 95-100% NOx Reduction
01 July 2008
A new, patented catalyst developed by scientists at the US Department of Energy’s (DOE) Argonne National Laboratory that can reliably and economically reduce between 95 and 100% of NOx emissions from diesel-fueled engines has been licensed to Integrated Fuel Technologies, Inc. (IFT), a start-up company based in Kirkland, Wash. The new in-line SCR deNOx system uses onboard diesel fuel as the reductant, rather than urea or ammonia as used in current SCR systems. (Earlier post.)
Argonne and IFT aim to have the technology—named Diesel DeNOx Catalyst—meet standards set by the California Air Resources Board, the strictest in the US. IFT plans to integrate the Diesel DeNOx Catalyst into its existing products that can be sold to original equipment manufacturers (OEMs).
The key to the Diesel DeNOx Catalyst technology is the reductant. ...it is the diesel fuel that reduces the NOx to nitrogen...The catalyst achieves such high rates of conversion because of its interactions with the hydrocarbons in the diesel fuel.
—Christopher Marshall, the Argonne chemist who led the development of technology
The catalyst is a Cu-ZSM-5 zeolite with copper ions attached within its micropore structure with an external coating of cerium oxide (CeO2. Previous work with Cu-ZSM-5 and similar catalysts found that they performed poorly at removing NOx from diesel exhaust. They require temperatures higher than normal diesel exhaust temperatures and don’t work well in the presence of water vapor.
Using Argonne’s Advanced Photon Source to analyze the structure and performance of various catalysts, Marshall’s group developed an additive that allows Cu-ZSM-5 and similar catalysts to overcome these difficulties.
Our new cerium-oxide additive is the breakthrough that makes it work. When it’s combined with Cu-ZSM-5, the resulting catalyst works at normal exhaust temperatures and is actually more effective with water vapor than without it. With a lean fuel-air mixture, it removes as much as 95% to 100% of NOx emissions.
—Christopher Marshall
Marshall and Argonne fellow researchers have also found the Diesel DeNOx Catalyst to be economical to make and use.
The ability to use diesel fuel as the reductant eliminates the need for onboard storage of compounds like ammonia or urea that existing technologies use as reductants, reducing the amount of additional weight a vehicle has to carry, and allowing for more efficient use of a vehicle’s fuel.
OEMs like PACCAR, Cummins, Siemens, BASF, Corning and John Deere have expressed an interest in IFT products enhanced with the Diesel DeNOx Catalyst. These companies want to know if the technology can survive continuous testing.
—IFT president Robert Firebaugh
IFT is also collaborating with Argonne under a two-year research agreement to test the technology’s longevity in real-world use and to demonstrate it in real world applications to determine if it can meet a broad array of transportation applications.
The Diesel DeNOx Catalyst is a low-cost technology given the usable lifetime of the catalyst, which is about 400,000 miles. A typical semi-tractor trailer or shipping and delivery service truck is driven about 45,000 miles in year, according to the American Trucking Association.
Marshall said that the catalyst can also be easily retrofitted for installation on existing diesel engine vehicles. “There is a potentially large pool of customers for this technology, given the 11 million diesel engines currently on the road.”
Funding to develop the Diesel DeNOx Catalyst was provided by Argonne’s Laboratory-Directed Research and Development program.
Resources
Michael K. Neylon, Mario J. Castagnola, A. Jeremy Kropf, and Christopher L. Marshall (2003) “Bifunctional Catalysts for the Selective Catalytic Reduction of NO by Hydrocarbons”
Michael K. Neylon, Mario J. Castagnola, Norma B. Castagnola and Christopher L. Marshall (2004) “Coated bifunctional catalysts for NOx SCR with C3H6 Part I: water-enhanced activity”, Catalysis Today, doi: 10.1016/j.cattod.2004.05.007
Is this also something that could be used on gas cars to enable lean air/fuel ratios at light/moderate loads?
On diesels, this catalyst combined with a particulate filter sounds like a winner.
Posted by: | 01 July 2008 at 03:28 PM
It sounds like the same lean NOx catalyst that uses hydrocarbon fuel as reductant but with additive. The HC-SCR developed a decade ago has proven not sucessful as the NOx reduction is not very high, about 35%. The system also requires two catalysis, low temperature and high temperature. I would like to see anything higher than 85% over the FTP cycle.
Posted by: HC | 01 July 2008 at 05:42 PM
Clean or not diesel will not become a big market in US, there is simply not enough diesel fuel available for this. period
Posted by: Treehugger | 01 July 2008 at 06:58 PM
(1st post was mine, btw)
Even without diesel becoming more popular because of high diesel prices, I would love to see more diesels get cleaned up.
Every day on my daily commute diesels can be seen spewing out tons of soot and I'm sure tons of NOx as well. Cleaning all those diesels up will do wonders for air quality around any heavily travelled thoroughfare.
Posted by: Dave | 01 July 2008 at 11:51 PM
Because many kinds of engines can be run hot (lean, high-compression) and minimize all their emissions _except_ NOX, this development should allow the ICE to enter its obsolescent years in style. (Still good for plug-in hybrids.) Provided that the developers address alternative fuels in a timely fashion. Standard diesel, based on petroleum, has left us as an economically attractive fuel.
Ethanol or (potentially-bio) propane could be highly efficient and low-emissions when burned this way. Ethanol could go almost as far on a unit of volume as gasoline despite its 66% lower energy content, and I don't imagine much aldehyde would escape combustion. Biodiesel too could be especially clean-burning with extremely low mutagenicity of the particles that do get past the trap (even with a more cost- and fuel-efficient, laxer trap), and this catalyst would solve the one emissions problem you have left. There's DME and many other things you can burn in a diesel engine. It would be a shame if the developers put consumers into the dilemma of having to choose between local clean air (plus satisfying regulations) and low net CO2/oil freedom solutions, by supporting only kerosene diesel.
It is not encouraging, though, that they appear to have gone years from discovering the catalyst system to concluding that they could use diesel as the reductant, versus the propene that they started with.
If our guys in Washington are doing their job, they will ensure we get a complete solution.
Posted by: P Schager | 02 July 2008 at 01:47 AM
For achieving advantages of both gasoline and diesel engines without their shortcomings, a two-stroke homogenous charge spark ignition (HCSI) engine has been created. It has a high expansion ratio of a diesel engine and a low compression ratio of a gasoline engine. The difference in stroke lengths is utilized for replacing the exhaust gas with homogeneous charge such that a two-stroke engine configuration is obtained to increase power density for downsize. It is equivalent to a two-stroke Miller cycle engine without the needs for a supercharger and intercooler. Having a gasoline engine compression and combustion processes and a diesel engine expansion process, a two-stroke HCSI engine achieves advantages of both engines without their shortcomings. It has a unique method to provide homogenous charge to the cylinder for minimizing emissions. It is a much simpler way than Mercedes' New DiesOtto Technology. Low compression ratio for achieve homogeneous charge low temperature combustion (LTC) to eliminate NOx is better than any aftertreatment. A patent is pending. If you are interested, Please contact me.
Posted by: Pao Chi Pien | 02 July 2008 at 08:35 AM
Two questions on this technology:
1) If you're using diesel as your reducing agent for NOx, how much do you need and how much does that effect your hydrocarbon/CO/CO2 emmisions and efficiency?
2) Considering an increasing number of Diesels are using advanced turbo charging and exhaust gas recirculation (and thereby lowing the exhaust temperature) is the kinetics of this reaction good enough to handle the lower exhaust temperatures?
Posted by: todd | 02 July 2008 at 09:53 AM
Pao, what is the local flame temperature you expect from your HCSI engine, that qualifies LTC.
Posted by: HC | 02 July 2008 at 11:07 AM
Dear HC,
The local flame temperature depends on the temperature at the end of a compression process and fuel equivalence ratio. At low-loads with small compression ratios, local flame temperature will be low. Homogeneous charge combustion produces homogeneous products of combustion without unburned hydrocarbon (UHC) regardless whether it is autoignition combustion or spark initiated combustion. For homogeneous charge autoignition combustion, the whole mixture burns simultaneously and no burned mixture is compressed into a higher temperature after burning to form hot temperature zone. It is often stated that homogeneous charge increases fuel efficiency and reduces emissions. However, the fuel efficiency is essentially a function of the expansion ratio.
Posted by: Pao Chi Pien | 03 July 2008 at 11:40 AM
What I find interesting is that in the end, the diesel engine may fulfill Rudolf Diesel's original vision: an internal combustion engine that can run off biomass-derived oils. (We forget that the first prototype engine ran off peanut oil, of all things!)
There's now extensive research into growing oil-laden algae on a HUGE scale and processing the algae into diesel fuel and its closely-related derivative, heating oil. Once we see this reaching industrial-scale production (probably within the next 15-20 years), we'll see trucks, railroad locomotives and the majority of oceangoing ships switch to this type of diesel fuel, probably in a B85 (85% biodiesel fuel and 15% petroleum diesel fuel) mix so it could operate in low temperatures. And the best thing of all is that the algae can be grown even with seawater, avoiding the potential problem of competing for freshwater resources.
With new technologies such as advanced particulate traps and various types of deNOX systems, diesel engines can be just as clean as gasoline engines.
Posted by: Raymond | 05 July 2008 at 06:20 AM
There are several companies looking at turning plant cellulose into ethanol, most already reaching the point of building a pilot plant to test scaling up the technology. Because plant cellulose is far more common than corn, wheat and sugar beet production combined, this could open the way to make ethanol on a scale that makes the Brazilian ethanol program seem like a minor event in comparison
Posted by: Richard Carter | 07 July 2008 at 11:39 AM
The only reason diesel engines produce more pollution than gasoline engines is that they are hardly ran at there stoichiometric settings leaving a cat. useless. Rather, they are run rich with lots of HC and Soot or lean with lots of NOx. If someone were to apply the technology of Vapor Fuel Technologies - http://www.vftllc.com/product.htm to a diesel one may find that if they were running the diesel engine at stoichiometric with a standard cat. the emissions would be much less and could still have the gains of the original diesel because the dilution is that by thermal expansion or by volume like a hot air balloon instead of a dilute mixture by means of EGR or excess Oxygen. Just my thought anyhow, someone with more insight and understanding in this world should look into it if what you say about the growth of diesel is true.
Posted by: LR | 07 July 2008 at 03:33 PM
NOX gases are made by lightning naturally. There are fertilizer plants burning up tons of natural gas so that NOX gases can be made to make into fertilizers. Perhaps is would save a lot of energy if the engines were legally required to be optimized to produce as much NOX as possible and then to condense the water in the exhaust and then then to absorb the NOX in the water and pump it on to the ground. The engine of a car should be left at home or work, except for an emergency engine, in an extreme plug in hybrid. Most of the travel is done by battery, and the engine runs to charge the battery; heat and cool the home while condensing the exhaust water and fertilizing the grass.
I will have to read up on NOX gases again to see why they are considered polutants when soil bacteria produce them all the time, and big factories are useing them to make fertilizers. ..HG..
Posted by: Henry Gibson | 01 August 2008 at 05:31 PM