Briefly, the nitrogen oxides (NOx) contained in the exhaust gas are converted into nitrogen (N2) and water (H2O) in a chemical reaction by the ammonia (NH3) contained in the urea and released by the exhaust gas.
This is done in a special catalytic converter, SCR catalytic converter (SCR = selective catalytic reduction), which is added to the exhaust system. The nitrogen oxide reduction is carried out without changing the engine combustion and thus ensuring the very good efficiency of diesel engines.
AdBlue® is stored in the vehicle in a separate tank. It is not fed to the engine and has no connection with the combustion process, but is directed into the exhaust stream by means of an injector or pump.
In the SCR catalytic converter, the above-described chemical separation of nitrogen oxides into nitrogen and water occurs, which considerably reduces the emission of nitrogen oxides, which is important for meeting the Euro-6 standard.
The introduction of AdBlue® can be attributed to the ever more stringent requirements to minimise expelled pollutants.
Emission standards regulate limit values for motor vehicles in terms of the expulsion of pollutants, including carbon monoxide (CO), nitrogen oxides (NOx), hydrocarbons (HC) and particles (PM). Vehicles are thus classified into different pollutant classes and these form the basis for the calculation of vehicle taxes and congestion charges for trucks.
Emissions standards are raised significantly every few years and become obligatory from a certain date for all newly released vehicles. Older vehicles are more expensive in terms of maintenance, congestion charges and vehicle tax, and many cities restrict the access of older vehicles to certain environmental zones.
Currently, the highest standard in the EU for trucks is Euro-6, which corresponds approximately to the standard EPA10 (North America) or Post NLT (Japan). Euro-6 has been applied since 1 January 2013 and has been obligatory from 1 January 2014 for newly released vehicles. The illustration shows the emissions standards trend in the trucks sector; it is clear here that the jump from Euro-5 to Euro-6 alone has reduced the permitted emissions quantity of nitrous gases by around four times. This step is impossible for any commercial vehicle manufacturer to implement without the use of AdBlue® Technology.
Applicable to cars since 1 September 2009 is the standard EURO-5, which has been obligatory for all newly released vehicles since 1 January 2011.
For units and equipment that come into contact with AdBlue®, the following materials are compatible:
The properties of work pieces manufactured from polymers depend greatly on the processing itself. For this reason it is recommended that in all cases written confirmation be requested from suppliers of work pieces confirming the mechanical resistance of the materials for use with AdBlue® within the intended temperature range. This should also confirm that the specifications of AdBlue® are not negatively affected if it comes into direct contact with this work piece under these conditions.
AdBlue® is non-toxic, environmentally sustainable and not hazardous to health. AdBlue® presents no particular health hazard in the sense of the European Chemicals Act. It is categorised as water hazard class 1 (= slightly hazardous to water) under the Federal Water Act (WHG) and is not a hazardous material under ADR. AdBlue® can be recycled by microbes and is therefore very easily decomposed. Skin contact should be avoided. Residues can be sluiced with water.