Good news . according to the Environmental Protection Agency we are less than a year away from eliminating 2.6 million tons of nitrogen oxide (NOx) emissions, 8,300 premature deaths, 5,500 cases of chronic bronchitis, 360,000 asthma attacks and 1.5 million lost work days.
The bad news . well, it's according to the EPA.
The real news . Jan. 1, 2010, marks the implementation of EPA's Onboard Diagnostic Requirements for Diesel Highway Vehicles Under 14,000 lbs. This will make the U.S. emissions standards the most stringent in the world.
What it actually means is that starting in 2010, diesel trucks will be required to convert to the Selective Catalytic Reduction systems.
That can be both good news and bad news.
SCR is a cost-effective and fuel efficient way to control diesel vehicle emissions, according to its supporters. It is designed to reduce the levels of NOx in excess of 90 percent by using ammonia as a reductant within the catalyst system . which is critical for diesel truck manufacturers who have to reduce their NOx levels by 90 percent in 2010.
NOx is an air pollutant which causes smog. It also causes asthma and respiratory disease and heart disease. The process of using ammonia as a reducing agent in the selective catalytic reduction of NOx was actually invented in 1957 and expanded into commercial use in 1978. So the concept has been around for a few years.and has a fairly well-documented track record.
Diesel truck manufacturers have looked at three ways to lower NOx emissions in new vehicles. First is to re-circulate exhaust gas (which is a common practice on today's vehicles and has helped cut emission levels). Second is the combination of re-circulating the gas in combination with an "absorbing" catalyst to help soak up and break down NOx molecules before they leave the tailpipe. The third approach is to use selective catalytic reduction with diesel exhaust fluid (DEF).
Here's how it works: DEF (urea solution) is held in a separate storage tank and is injected as a fine mist into the hot exhaust gases. The heat actually breaks the urea down into ammonia, which is a natural NOx-reducing agent. Once the exhaust reaches the catalytic converter, the ammonia breaks the NOx into nitrogen gas and water vapor. So when it leaves the tailpipe, it's as clean or cleaner than the air around it.
The amount of DEF mist used represents about 2 percent of the diesel fuel.
DEF will start to freeze at 12 degrees F, requiring heated lines to keep the fluid in a liquid state in extreme cold temperatures . but it does warm up quickly. Urea is also corrosive to aluminum and must be stored in plastic or stainless steel tanks. However, it is not toxic.
There could also be some issues with extreme warm temperatures if the vehicle sits for extended periods of no use. Urea begins to deteriorate and evaporate in temperatures over 86 degrees F. If temperatures reach over 130 degrees F, urea becomes hazardous and begins to decompose.
Although your vehicle will be equipped with DEF gauges and warning lights alerting you to the status of your tank, if you run empty of DEF, your truck may not start. And the sensors can determine the composition of the DEF added to the truck, so you can't substitute urea fertilizer, water or even urine.
It is a stable product with a shelf life of more than a year. DEF will probably cost about $2.75-$3 per gallon when sold in bulk. Prices are driven by a global supply and demand. Since July 2007 the prices have increased more than 150 percent.
The increased cost for SCR could possibly be made up during the life of the vehicle through improved mileage. Supporters of this technology claim that SCR can decrease fuel consumption up to 9 percent . although the application of the process is beyond the power-making stage of the engine. They say it will pay for itself . but ultimately it is always the user who pays.
DEF is the same as AdBlue, a trademarked name in Europe for DEF. (For the past few years Europe has been producing BlueTec vehicles like the Mercedes-Benz E320, which won the 2007 World Green Car of the Year.)
DEF tanks will be standard equipment with SCR technology in new diesel vehicles starting 2010. But it's up to the driver to fill them . just like filling your fuel tank. The good news is that you get about 500 miles to a gallon of urea.
DEF is a simple solution of urea and water that is safe and should start becoming available at leading truck stops across the country in 2010. It is somewhat related to your standard nitrogen fertilizer used by farmers . and even your run-of-the-mill urine.
It is likely that less than 10 percent of the diesel trucks in the U.S. in 2010 will use urea. However, the use will likely double between 2010 and 2011 . and continue to increase rapidly as new vehicles begin to phase out older vehicles.
As use increases, there could be increased competition between fuel grade urea and that used for fertilizers. Right now more than 90 percent of the urea produced throughout the world goes for fertilizer . but that number will decrease as more diesel vehicles manufactured after Jan. 1, 2010, are required to use DEF for emissions control.
This increased demand could also drive the price of urea up . although there's always a chance that increased production of urea can lead to reduced prices. And urea producers tend to get better returns when it is sold as fertilizer. For commercial vehicle applications, urea must have a consistent high purity level with a concentration of 32.5 percent urea and 67.5 percent of de-mineralized water.
So the good news is we'll be saving lives and breathing cleaner air. The bad news . well, let's go back to that EPA thing again.