Advanced Engine-Control System Reduces Biodiesel Fuel Consumption and Emissions

www.sciencedaily.com ^ | Jan 27, 2010 | Staff

[Red Badger]

Researchers from Purdue University and Cummins Inc. have developed an advanced "closed-loop control" approach for preventing diesel engines from emitting greater amounts of smog-causing nitrogen oxides when running on biodiesel fuels.

Operating truck engines on a blend of biodiesel and ordinary diesel fuel dramatically reduces the emission of particulate matter, or soot. However, the most modern and efficient diesel engines burning biodiesel emit up to 40 percent more nitrogen oxides at some operating conditions, and fuel economy declines by as much as 20 percent.

Unlike conventional diesel, biodiesel contains oxygen, and the researchers have shown that this presence of oxygen is responsible for the majority of the higher emission of nitrogen oxides, said Gregory Shaver, an assistant professor of mechanical engineering.

Another key factor is a recent innovation called exhaust gas recirculation, which reroutes exhaust back into the engine cylinders to reduce emissions. The researchers found that nitrogen oxide emissions rise by a higher percentage in engines equipped with this exhaust-recirculation technology compared with older engines that do not. However, the newer engines still emit less nitrogen oxides than the older engines.

The research addresses the need to reduce nitrogen oxide emissions and fuel consumption. Researchers at Purdue's Ray W. Herrick Laboratories used a Cummins 6.7-liter, six-cylinder diesel engine, a popular power plant found in Dodge Ram pickup trucks.

"We were able to improve the fuel economy with a biodiesel blend while reducing nitrogen oxides to where they were with conventional diesel," Shaver said. "At the same time, we were able to maintain the customary biodiesel reductions in particulate matter emissions compared to ordinary diesel fuel while not increasing noise emissions."

Fuel economy still is problematic, however, because biodiesel has 10 percent to 12 percent lower "energy density," or the amount of energy liberated during combustion, compared to regular diesel...

[Red Badger]

Gregory M. Shaver, from left, an assistant professor of mechanical engineering at Purdue, and graduate student David Snyder discuss how to modify a commercial diesel engine with a new technique that promises to reduce emissions of nitrogen oxides for engines running on biodiesel. Graduate student Gayatri Adi (background) reviews software algorithms needed for the new technology. (Credit: Purdue News Service file photo)

Rest In Peace, old friend, your work is finished.....

If you want ON or OFF the DIESEL ”KnOcK” LIST just FReepmail me.....

This is a fairly HIGH VOLUME ping list on some days.....

[Red Badger]

Knock!..............

[the_daug]

If the effort was deferred to produce the maximum efficiency from and engine instead of emissions would it result in less emissions from less fuel being consumed?

[Ole Okie]

Exhaust gas recirculation has been used in gasoline engines since the 60’s or 70’s to reduce NOx. Guess I’m surprised it hasn’t been used heretofore on engines using genuine diesel fuel.

I think compression ignition engines are going to be one wave of the future. They’re a natural for their splendid efficiency, hence MPG. Any efforts to improve the exhaust quality are welcome indeed.
I

[Red Badger]

That is true. If an engine could be designed to withstand the temperatures, a hotter running engine would be more efficient, thus less fuel consumed, ergo less pollutants in the exhaust. Ceramic engine blocks and pistons have been proposed and in the case of ceramic pistons, some have even found their way into the production engines of certain personal watercraft, Jet Skis, et al. The enormous cost of producing ceramic engine blocks is still cost prohibitive for large engines...........