FAQ

What is AdBlue®?

AdBlue® is a urea solution of the highest purity whose quality is specified in DIN 70070. It is based on synthetic urea and is colourless, odourless and is neither a hazardous material nor a hazardous good.
AdBlue® is used downstream of the engine for the chemical conversion of harmful nitrogen oxides that arise during combustion of diesel fuel into nitrogen and steam. This technology is known as SCR waste gas aftertreatment and is used to fulfil the EU pollutant emission standards EURO 4 and EURO 5 for exhaust gases from commercial vehicles.

Where does the name AdBlue® come from?

"AdBlue" is a pseudonym created by an international, interdisciplinary working group of the Verband der Automobilindustrie e.V. (VDA). AdBlue® is a registered trade mark of the VDA with world-wide property rights. The right to use the name can be acquired with a license.

Which alternatives are there to fulfil EURO 4 and EURO 5?

At present, two technologies are competing to fulfil the pollutant emission standards EURO 4 and EURO 5 for commercial vehicles: cooled exhaust gas recirculation (EGR) and SCR exhaust gas aftertreatment (SCR = selective catalytic reduction). Whereas EGR only complies with EURO 4 at present, SCR reliably complies with both EURO 4 and EURO 5. SCR will also be the basic technology for even more stringent directives (e.g. EPA 10 in the USA or EURO 6, which is already being discussed).

When do the new exhaust gas directives come into force?

EURO 4 goes into force on the 1st October 2005 and EURO 5 on the 1st October 2008. After a one-year transitional period, new vehicles in those countries in which the exhaust gas directives apply, will only be granted a license if they comply with these directives.

When will vehicles with SCR technology be available?

DaimlerChrysler already started delivering the first vehicles in the 1st quarter of 2005 as part of its BlueTec program. Further manufacturers of commercial vehicles, such as IVECO, DAF and VOLVO, have announced that deliveries will start in 2005. RENAULT VI will follow in Autumn 2006, at the latest.
MAN and SCANIA will initially offer vehicles for EURO 4 with EGR, but will also have vehicles with SCR in their program in good time for EURO 5.
In Japan, NISSAN DIESEL has already started producing vehicles with SCR technology.

How is AdBlue® supplied?

The well-known European urea producers have built up an area-wide distribution network with their sales partners.
One of SKW Piesteritz partners is the KRUSE KG, which has their own branch offices and their own supply network with cooperation partners in Germany and other European countries to supply AdBlue® as well as a comprehensive range of tanking equipment. Individual consulting ensures that supplies are tailored to the customer's requirements.
In Germany, the depots belong to the owner's of the vehicles will provide the primary supply. The big mineral oil companies are only just starting to build up an infrastructure for public fuelling stations.

Can diesel be mistaken for AdBlue® during tanking?

To prevent this as far as possible, constructive measures have been implemented on the interface between the AdBlue® tank and the fuel pump nozzle. The diameter of the AdBlue® fuel pump nozzle is smaller than that of its diesel analogue. This prevents diesel being filled into the AdBlue® tank.
In the AdBlue® tank opening there is a magnetic ring that activates the fuel pump nozzle only after it has been inserted. However, this system is only used with public fuelling stations or with minibulk facilities. Simple tanking systems, consisting of an IBC, a pump, a volumeter and a fuel pump nozzle do not have such a security system at present.

How long and under which conditions can AdBlue® be stored?

The optimum storage temperatures lie between –5°C and +25°C. Under these conditions, it can be stored for at least 1 year without any loss of quality.
The freezing point (crystallisation) of AdBlue® is –11°C. Storage temperatures above 30°C lead to hydrolysis, i.e. cleavage of the urea into ammonia and carbon dioxide. The rate of this reaction increases as the temperature increases.

Which materials are suitable for use with AdBlue® and which are unsuitable?

The contact between AdBlue® and stainless steels or plastics does not cause any problems.
Contact with copper, zinc and their alloys must be strictly avoided. Aluminium is also regarded as critical. AdBlue® contaminated with these elements damages the catalyst.

What happens when the AdBlue® tank is empty and there is no filling station in the vicinity?

Analogous to a fuel gauge, there is also an AdBlue® tank gauge that indicates the level in the tank. The AdBlue® tank has been designed so that AdBlue® has to be tanked every time that diesel is tanked. The vehicle can still be driven if the AdBlue® tank is empty; however, it no longer complies with EURO 4 or EURO 5. From EURO 5, at the latest, the vehicle will be equipped with an OBD (on-board diagnostic) unit that monitors the faultless functioning of the SCR technology.
Possible fines after an official detection of non-compliant operation of the SCR system are under discussion. Technical measures, e.g. reduction of the engine power or a limited mileage if the SCR equipment is not working are also possible.
To prevent such situations, it is recommended that a spare can of AdBlue® should be carried until an area-wide network of public fuelling stations has been established. A distance of 500 km requires approx. 10 l AdBlue®.

Which advantages and disadvantages does the SCR technology have compared to EGR?

Advantages of SCR technology

Disadvantages of SCR technology

Can AdBlue® also be used with biodiesel?

Yes, as long as the vehicle is permitted to use biodiesel. The consumption of AdBlue® may be higher than that for conventional diesel grades because the combustion temperature in the engine is higher for biodiesel. This results in the production of more nitrogen oxides which then have to be reduced.

How high is the AdBlue® consumption?

The consumption of AdBlue® is given as approx. 4 % of the diesel consumption for EURO 4 vehicles and approx. 6 % for EURO 5.

Can EURO 3 vehicles be retrofitted with the new SCR technology?

No. New engines have been developed together with the SCR technology that are especially tailored to this technology. They have an optimised performance and a lower fuel consumption. More nitrogen oxides are produced intentionally so that the particle emissions can be reduced. Vehicles of previous generations also lack space for the SCR equipment (AdBlue® tank, SCR catalyst, etc.).

Can EURO 4 vehicles be retrofitted for EURO 5?

Technically, retrofitting is possible; however, is not worthwhile economically.
Not only must a larger catalyst be installed, but the electronic control system must also be adapted and an OBD must also be retrofitted.

What incentives are there for low-pollutant vehicles in Europe?