EPA Regulations The Environmental Protection Agency recently set new standards on the amount of NOx emissions given off by diesel engines. By 2010, new diesel engines will be required to emit no more than 0.2 grams per brake horsepower hour of nitrogen oxide (NOx) and 0.14 of non-methane hydrocarbons (NMHC) (www.epa.com). As a result, new diesel engines in 2010 will produce less than 10 percent of the emissions of 2001 models. In other words, come 2010, all new diesel-powered pickups will have to meet tougher federal diesel emission standards that will reduce allowable nitrogen oxide levels by 90 percent from today and by 96 percent from 1994. The EPA is also requiring that, by 2010, 100 percent of the diesel fuel sold in the country meet the 15 ppm standard. NOx is a major air pollutant that contributes to smog, asthma, respiratory and heart diseases. It is a byproduct of diesel’s high combustion temperatures, which results from the high frictional heat levels created by compressing air in the cylinders to the point where it can ignite diesel fuel without using a spark. This is unlike a gas engine, which uses spark ignition to burn petrol. Solution for EPA Regulations There are basically 2 ways to lower NOx emissions in diesels: 1) The first is exhaust gas recirculation (EGR). EGR recirculates a portion of the engine's exhaust back into the engine at a lower temperature. The cooled gases have a higher heat capacity and contain less oxygen than air, lowering combustion temperatures and reducing the formation of NOx. EGR is prevalent in today’s clean diesel engines to reduce NOx, but it’s not efficient enough in current form to meet 2010 emissions levels. 2) The second and most recent approach is a selective catalytic reduction system (SCR) that uses DEF (New Technology). The urea-based solution is held in a separate storage tank and injected as a fine mist into the hot exhaust gases. The heat turns the urea into ammonia that, when combined with a special catalytic converter, breaks down the NOx into harmless nitrogen gas and water vapor. Several truck manufacturers, including Volvo, Detroit Diesel, and Paccar, have decided to use selective catalytic reduction (SCR) systems to comply with the 2010 requirements. Ford, GM, and Chrysler will also use Diesel Exhaust Fluid to lower NOx emissions from the exhaust, but only in its new 2010 vehicles. Demand for DEF Since 2004, SCR has been serving Europe’s diesel needs, with over 600,000 SCR equipped vehicles on the road worldwide. In the United States, Detroit Diesel has logged over 15,000,000 miles of testing the BlueTec emissions system (Mercedes Benz’s brand for SCR). Experience in Europe indicates that average DEF consumption is about 5% of diesel fuel consumption. Refilling the DEF tank occurs at approximately the interval of recommended oil changes for light-duty vehicles. The interval varies based on application for medium and heavy duty vehicles. It is believed that it is going to be a 2 to 3 percent fuel to urea (DEF) ratio. Knowing that, it takes about 2 to 3 gallons of urea per 100 gallons of fuel. Other than refilling the tank, no actions are required by the driver for an SCR/DEF system to function. A warning light alerts the driver when the DEF level is approaching a low level. If the DEF were allowed to run out completely, the vehicle would experience reduced performance or would cease to operate. Cold weather is another consideration. Because DEF freezes at 12 degrees Fahrenheit, it must be protected from extreme cold during storage. Commitments are in place to ensure that Diesel Exhaust Fluid is available in more than 1,800 locations in North America by 2010, including: · Daimler Trucks North America support network · Detroit Diesel Engine support network · Volvo Truck dealerships · Mack Truck dealerships · Peterbilt Truck dealerships · Kenworth Truck dealerships · Cummins Engine support network · Select truck stops · CDI support networks Come Jan. 1, 2010, most new diesel pickup truck buyers are going to have to take into consideration that DEF is needed for clean emissions. DEF and SCR Systems Diesel Exhaust Fluid (DEF) is a solution made up of purified water and 32.5 percent automotive-grade urea that is used as a carrying agent for the ammonia needed to reduce nitrogen oxide (NOx) emissions from vehicles into nitrogen, water and carbon dioxide (CO2). It is basically a liquid reducing agent that reacts with engine exhaust in the presence of a catalyst to convert smog-forming NOx into harmless nitrogen and water vapor. Today, Diesel Exhaust Fluid is certified by the American Petroleum Institute, which ensures that Diesel Exhaust Fluid is a stable, non-toxic, odorless and completely safe solution. The urea used for Diesel Exhaust Fluid is automotive-grade. Urea in additional forms is widely distributed for many other industrial and agricultural needs, including emissions control at public utilities and power plants. DEF, sometimes known by the name of its active component, urea, is a key component of selective catalytic reduction (SCR) systems, which help diesel vehicles meet stringent emission regulations set by the EPA. To get a picture of how DEF works with SCR systems, the DEF lines would run from the DEF tank to DEF injectors that squirt the urea-water mix into the exhaust stream, behind the diesel particulate trap. There the DEF solution decomposes into ammonia, which mixes with the nitrogen oxide to break down into nitrogen and water. It also cools extremely hot gases, which acts like a self-cleaning oven during its regeneration process to incinerate trapped soot to begin the soot-trapping cycle again. Coolant lines near the DEF injectors ensure they run at the optimal temperature for the ideal chemical reaction. Urea is a nitrogen-containing compound that transforms into ammonia when heated. It occurs naturally from natural gas and is used in various industries, including as a fertilizer in agriculture. A urea-based DEF is used widely in Europe under the brand name AdBlue. Suppliers of DEF Significant investment is being made across the industry to create the infrastructure that will ensure Diesel Exhaust Fluid quality is upheld and that the solution is conveniently available. The industry consumers, including truck manufacturers, truck stops, retail fueling stations, fuel distributors, and urea providers are developing a network of bulk DEF filling stations at truck stops and diesel service stations across North America. DEF also will be available at participating auto dealers, auto parts stores, and other retail locations. It likely will be distributed in individual containers designed for filling one vehicle as well as in bulk tanks for fleet or retail fueling station applications. Some distributors may also recycle DEF. Pricing Development DEF is expected to cost about $2.75 a gallon when pumped at truck stops and other retailers, according to the North American SCR Stakeholders Group, an industry alliance of truck and engine manufacturers, regulatory agencies and associations, and DEF infrastructure partners and suppliers. It will be packaged in many ways including 2.5 gallon jugs, bulk storage and DEF dispensing units. Knowing that an SCR system's urea tank needs to be refilled from time to time, it will add an ongoing operational cost to keep the truck in compliance with the law. According to Bernard Heil, vice president of Truck Product Engineering Power-train for Germany's DaimlerChrysler AG, which owns the Freightliner, Sterling, and Western Star truck brands in the United States, SCR-based emissions reduction systems should add approximately $4,000 to the cost of a new truck. However, improvements to fuel economy by using SCR, is up to 7 percent in European trucks. He believes that it could help offset that higher sticker price cost to a degree over the life cycle of the vehicle. Illustration