AdBlue is the name used internationally for an additive developed for the chemical and motoring sectors.
It's an extremely high purity, 32.5% aqueous solution of urea (minimum 31.8% - maximum 33.3%) that transforms nitrogen oxides into nitrogen (N2) and water vapour (H2O) by means of chemical reduction.
Content of various metals must not exceed 0.2 mg/kg for each of them in order not to contaminate the catalytic converter. This means AdBlue cannot be substituted by urea used in agriculture.
The composition and quality standards are regulated by DIN 70070.
AdBlue is an odourless, colourless synthetic product: it is not considered a dangerous substance inasmuch as it's neither flammable nor toxic.
Principle underlying catalytic reduction of nitrogen oxides.
AdBlue SCR technology has been in use since the early '80s in thermal and fossil fuel power stations, on gas turbines, locomotive diesel engines and large marine power units. In all these applications combustion is optimised with the dual aim of achieving improved performance and direct reduction of particulate emissions. Post-treatment is based on a simple principle: the chemical reaction of ammonia (NH3) with the nitrogen oxides NO and NO2 to produce two harmless substances – water vapour (H2O) and nitrogen (N2). These are the relevant formulas:
NO + NO2 + 2 NH3 2 N2 + 3 H2O
And for any residual oxygen present in the exhaust gases
4 NO + O2 + 4 NH3 4 N2 + 6 H2O
6 NO2 + 8 NH3 7 N2 + 12 H2O
In very large systems ammonia is drawn directly from pressurised tanks. With regards to road vehicles, the use of pure ammonia has been studied but in the end was abandoned because of problems of storing it on board trucks and in refilling stations. The normalised urea technique in the form of a solution – AdBlue – was preferable for two reasons: this product is not categorised as a dangerous
substance, there is no danger in the event of spills and it's easy to store both on board vehicles and at transporter premises, despite the limitation that it crystallises at temperatures below -11°C.
Distribution of AdBlue.
A European-wide distribution network is being set up to cover the rapid expansion forecast for the number of vehicles equipped with SCR.
Producers of AdBlue are able to set up a direct distribution system for transporters with large vehicle fleets. They also supply fuel companies and there is a plan to install AdBlue pumps alongside diesel pumps. A number of stations are already operative in Germany and others are being introduced in several other European countries.
To ensure widespread distribution and an appropriate level of service for customers right from the start, Iveco is organising the supply of AdBlue to its dealer network in cooperation with a leading international partner.
The agreement currently being finalised calls for distribution of AdBlue throughout Europe, with a level of service guaranteeing supply of the product within 48 hours after a request. This will be achieved thanks to the approximately 112 distribution points made available by our supplier and
operative throughout Europe starting 2006. There will be three different distribution and stocking systems: 10-litre disposable cans, 1,000-litre returnable containers (IBC) and about 4,000-litre containers (MiniBulk) that can be refilled with bulk product.
