Got NOx?

Mar 18, 2005

Pacific Northwest National Laboratory researchers have developed a new cost effective and energy efficient method for reducing oxides of nitrogen, or NOx, in diesel engine emissions. Called the reformer assisted catalysis, the process is three-fold -- "syngas" production, reductant synthesis and catalytic reduction of NOx in emissions.

Though they are the dominant choice in commercial trucks and heavy equipment, diesel engines are burdened with significant NOx emissions, which can affect breathing, visibility, vegetation growth, metals, fabrics and dyes.

In the most recent data collected by the U.S. Bureau of Transportation, national NOx emissions in 2001 were more than 22 million tons. As regulatory requirements on exhaust emissions become more stringent, reduction of nasty pollutants has become a high priority in automotive and other commercial industries.

PNNL began to work on this problem more than 10 years ago. Researchers developed a plasma facilitated catalyst, but recognized that a more energy- and cost-efficient system could be built, leading to the development of the reformer assisted catalysis.

The process includes treating hydrocarbon in a reformer before being introduced into the exhaust; diesel is then extracted from the fuel tank and reformed into syngas, a mixture of hydrogen and carbon monoxide.

Next, the mixture is chemically converted to dimethyl ether, which has proved to be highly selective for NOx reduction, from the syngas stream.

In the final step, catalysis, the ether mixture is injected into the exhaust, enhancing the performance of certain catalysts that allow for significant NOx reduction. Researchers took advantage of the earlier plasma catalysis system that offered changing the chemistry of the fuel to generate a better catalysis. They changed the process slightly to retain the oxygenated fuel in the exhaust, making it more cost and energy efficient.

Researchers plan to test the process on a small engine late this year.

Source: PNNL

Explore further: King Richard III died painfully on battlefield

add to favorites email to friend print save as pdf

Related Stories

Scientists discover gold's hidden value

Jun 20, 2014

(Phys.org) —Scientists from Cardiff are discovering new and unexpected uses for gold – a noble metal traditionally regarded as being chemically uninteresting due to its poor ability to react with other ...

Recommended for you

King Richard III died painfully on battlefield

5 hours ago

England's King Richard III might well have lost his kingdom for a horse. The reviled king suffered nearly a dozen injuries on the battlefield, but the fatal blows were probably only sustained after he had to abandon his horse, ...

History books spark latest Texas classroom battle

8 hours ago

As Texas mulls new history textbooks for its 5-plus million public school students, some academics are decrying lessons they say exaggerate the influence of Christian values on America's Founding Fathers.

Flatow, 'Science Friday' settle claims over grant

8 hours ago

Federal prosecutors say radio host Ira Flatow and his "Science Friday" show that airs on many National Public Radio stations have settled civil claims that they misused money from a nearly $1 million federal ...

'Hidden Treasure of Rome' project unveiled

9 hours ago

For more than a century, hundreds of thousands of historical artifacts dating back to before the founding of Rome have been stored in crates in the Capitoline Museums of Rome, where they have remained mostly untouched. Now, ...

Poverty rate drops for the first time since 2006

10 hours ago

The poverty rate in the United States has dropped for the first time since 2006, bringing a bit of encouraging news about the nation's economy as President Barack Obama and Congress gear up for the November elections.

User comments : 0