Vehicles that burn fuel to run produce a number of pollutants that are damaging to the environment. To combat this problem a process called Selective Catalytic Reduction (SCR) has been introduced to all heavy good vehicles produced after 2006. One of the vital ingredients to complete this process is AdBlue. It converts the harmful nitrogen oxides into water and nitrogen, which are harmless to the environment.
AdBlue is made up of a 32.5% aqueous urea solution and 67.5% water. It is widely used in the automotive and chemical industries across the world. The product needs to meet the DIN 70070 standard.
Because it’s not poisonous or flammable, AdBlue is considered a safe product. It is an artificial exhaust fluid that is colourless and unscented.
The nitrogen and water is released as a result of a natural reaction between the nitrogen oxides and ammonia. The particulates released are reduced and the vehicle runs better when using SCR. This process has been in use for around 30 years, when it was used in big marine dedicated units, train diesel machines, gas turbines and in fossil fuel and thermal power stations. The applicable formulas are detailed below:
NO + NO2 + 2 NH3 N2 + 3 H2O
The formula changes once oxygen becomes present:
4 NO + O2 + 4 NH3 4 N2 + 6 H2O
6 NO2 + 8 NH3 7 N2 + 12 H2O
Petrol stations have difficulties in storing AdBlue, meaning that it will be difficult to implement SCR technology into normal cars. This is also accompanied by the fact that it will be hard to store on smaller vehicles. Larger vehicles can exhaust the ammonia straight from the specified tanks. The regular urea method in the form of a solution – AdBlue – was required for two reasons: this produce is not titled as a hazardous substance, there is no risk in the event of leaks and it’s easy to store equally aboard vehicles and at transporter buildings, despite the drawback that it creams at temperatures below -11°C.