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 ethanolbut now urea, a basic input for food production, is also going into fuel," says Dr. Amit Roy, President and CEO of the Intern
|Contact: Dr. Thomas Hargrove|