US car manufacturers lead planning for urea solution supply

The US urea stakeholders group, coordinated by the Alliance of Automobile Manufacturers in Washington, is currently preparing to support the launch of the new range of SCR cars and SUVs in 2008.

SCR cars will be on the market in the US in 2008, two years earlier than the expected delivery of the first SCR trucks and buses. Therefore General Motors, DaimlerChrysler and other car manufacturers planning to include SCR technology at the top end of their diesel engine range have been foremost in planning and promoting a urea supply system.

There is general consensus that the quality standard for the urea solution should be based on the ISO standards developed in Europe for the commercial vehicle SCR market. In particular, it is likely that the ISO 22241-1 (quality characteristics) and the ISO 22241-2 (test methods) standards will be adopted largely unchanged. Perhaps most important from a practical standpoint is the 5ppm ISO limit for formaldehyde, which excludes the possibility of using fertilizer grade urea as a raw material for automotive urea solution. Fertilizer grade urea is widely available in most US states, but most stakeholders believe that its use in diesel SCR would result in a chaotic market and technical problems. Less certain is the implementation of the third and fourth parts of the ISO standard, which cover storage, handling and transportation of urea solution, and the filler interface. These may be seen as less applicable to the US market and may not used.

Regarding the generic product name for the urea solution, USCAR has endorsed the name "Diesel Exhaust Fluid" or "DEF". USCAR is an influential research organization composed of DaimlerChrysler, Ford and General Motors. However, some parties do not approve of "Diesel Exhaust Fluid", and other options may still be considered. It seems unlikely that AdBlue, the European trademark, will be used, since the European truckmakers are not involved at a detailed level in this discussion.

Major issues still to be addressed are the assurance of quality in practical use, and the supply chain model to be adopted given the relatively low consumption rates for cars with the focus on service intervals for refilling.