More urea needed for 2010 SCR engines?

NEW YORK — At least one heavy-duty truck manufacturer is testing higher doses of urea in prototype 2010 engines in order to drastically reduce fuel consumption of the future engines.

According to New York market analysts Bear Stearns, a source speaking to the firm says early tests of Selective Catalytic Reduction (SCR) have gone well. The company is one of a handful of OEMs offering SCR as the solution to reduce NOx is upcoming 2010 EPA-mandated engines.

The contact also revealed that in recent months his firm has begun to experiment with higher urea dosing levels than was initially expected. He explained that engines are being tested with about five to six percent urea per gallon of diesel, compared to one to three percent originally.

Urea is a Nitrogen-based reducing agent that, when injected into the exhaust gas upstream of the catalyst, drastically reduces NOx.

The purpose of increasing the rate is to improve the fuel efficiency of the engines — likely to be a high priority for truck buyers in 2010. By increasing the urea percentages, engineers might not have to do as much “in-cylinder” work to reduce emissions and allow for fuel economy.

While the tests are still in the very early stages, there’s a possibility that urea dosing rates could be higher than many in the industry initially expected.

That could raise the concern of some in the industry who have been warning that urea may not be readily available in North America as it is in Europe, where SCR has been used for years by OEMs to meet emission regulations.