AdBlue
From Wikipedia, the free encyclopedia
AdBlue is a trade name of AUS32 essentially it is a solution of urea in demineralised water (32.5%) used as an operating fluid in diesel-powered freight trucks to improve emissions. It is a common misconception that AUS32 is a fuel additive. AUS32 is stored in a separate tank to the fuel and is sprayed into the exhaust gases. Therefore, it is never mixed or added to the fuel.
AUS32 is taken along in a separate tank on the freight trucks. It is dosed in the hot exhaust gases in a specific catalytic converter. The oxides of nitrogen formed at combustion are converted into elementary nitrogen and water. This method is called Selective Catalytic Reduction (SCR).
The usage of AdBlue lies at 3 to 5% of the diesel usage. Because of this it becomes possible for diesel-powered freight trucks to satisfy the Euro IV emission standard introduced in 2005, as well as the future Euro V emission standard. Because there are already many of these so called "EURO V - trucks" or "SCR - trucks" on the road, filling stations that supply AdBlue are being built, expanding an infrastructure that makes use of urea in emission control feasible.
There are alternative methods of meeting the future Euro V emission standard; notably exhaust-gas recirculation (EGR) [1]: proponents of this technology point to the direct product costs and increased operational costs of AdBlue: storage, infrastructure, handling and filling; also extra weight and maintenance, along with a claimed increase in chassis weight of around 150 kg.
In order to ensure that the SCR system remains free from contaminants, correct materials of construction must be used for both storage and dispensing. Manufacturers of the SCR have specified that without using compatible materials of construction ions can be passed from the dispensing materials and into the porous head on the SCR. This can render the SCR ineffective and reduce its life expectancy from +500000 km to less than 200000 km. Equipment which may prove suitable for Urea solution is often not compatible with AdBlue and this common assumption has led to a number of systems failing prematurely.
To ensure that the AUS32 (AdBlue) is not affected by incorrect material specification operators should refer to the DIN70070 standard for production of AdBlue and the relevant CEFIC quality control document QAGD for AUS32.
Leading industry players such as Mercedes-Benz, Volvo Trucks, DAF Trucks and IVECO have collaborated on a website (operated by Integer Research Ltd), which includes a search engine that can be used to find filling stations that offer AdBlue, and which has maps showing their location. There are plans to extend this to parts of Asia and Australia.
Euro IV came into force on 1 October 2006. Euro V comes into force in October 2008 for new type approvals and one year later for all type approvals.
