Making blue into green
An integrated supply chain solution for adblue is cutting diesel engine emissions

Occasionally, regulatory activity triggers changes that support society, the environment and chemical commerce. An good example of this is the Dureal urea distribution system, created by chemical distributor Univar.

Dureal was set up in response to the strict Euro 4 and Euro 5 emission standards for heavy-duty diesel engines in commercial vehicles. These standards, which target nitrogen oxides (NOX) and particulates, will apply to all new vehicles: Euro 4 in October 2005 and Euro 5 by 2008. Attempts to reduce nitrogen oxides within diesel engines have increased fuel consumption and particulate emissions. Instead, engineers have found that they can use selective catalytic reduction (SCR) outside the engine to meet the Euro 4 and 5 standards without lowering efficiency.
In SCR, a high-purity 32.5 percent urea-based solution known as adblue reduces nitrogen oxides to nitrogen and water (see figure).

This system has been adopted by most of the major truck and bus manufacturers in Europe. But the need to ensure supplies of adblue posed a problem: there was no existing distribution system and the oil companies were reluctant to enter the market. This opened up an opportunity for a chemicals distribution company such as Univar to add value to urea, turning it from a commodity chemical into an environmental necessity. “Under the name ‘Dureal, the advanced adblue system’, Univar has set up a new distribution infrastructure to supply adblue to the European transport industry,” says Jacques Voogt, Director Innovation & Development, Univar Europe.
Liquid chemicals are normally transported in industry-standard bulk containers of 20,000–25,000 liters. To avoid problems with instability in part-full containers, they are shipped out full and returned empty. Univar realized that many adblue customers would need smaller quantities, so the Dureal system uses standard-size containers that have been adapted to dispense small amounts without becoming unstable when part-full.
Univar has also developed purpose-built Dureal storage and dispensing units for use at transport depots and filling stations. The units have telemetry systems for stock control and quality checking, temperature control to prevent freezing, and payment systems for retail sites. Other options include a system based on intermediate bulk containers (IBCs) for small and medium-size operators, another using a 200-liter drum with an electric pump, and 5-liter packs designed to be carried on board the vehicle.