Contrary to the name Ad Blue is a clear, colourless non- toxic liquid. It’s added to certain diesel vehicles which are fitted with selective catalytic reduction or SCR technology to reduce emissions and treat exhaust gas. Ad Blue is often rumoured to be made out of pigs urine however this is untrue. This rumour comes from it being a 32.5% solution of pure urea in mineralised water which is something that is found in urine although in much lower concentrations.
What is it used for?
In the automobile industry one of the greatest challenges is reducing emissions. New exhaust standards that have been introduced to look at the reduction of c02 emission levels and reduction in nitrogen oxides. Nitrogen oxides pollute the air causing smog, acid rain and are believed to contribute to respiratory issues.
How does It work?
The Ad Blue is fed into the exhaust and reacts to the nitrogen oxide gas which is produced during combustion , removing polluting elements of the exhaust gas turning it into harmless nitrogen, oxygen and water. This doesn’t only reduce the amount of emissions produced but also allows your vehicle to pass more strict standards that have been put in place. This Process is known as selective catalytic reduction and is only used in diesel engines
How is it stored?
Ad Blue should be stored out of direct sunlight between -6°c and 25°c in a clean and sealed container or dispensing unit out of direct sunlight. it is possible for Adblue to freeze at -11°c, so it’s important to be stored in an area that is not below this however if frozen it is possible to be thawed and then re used. Storing it in the wrong equipment or condition can lead to spills or contamination as the solution contains ammonia which is corrosive to some metals such as coppers. Ad Blue can only be stored in high density polyethylene , polypropylene or stainless steel containers. Storing it in the wrong equipment may result in costly damage to your vehicle due to contamination, which can result in SCR-catalyst replacement.
Ad blue contamination
In some cases people believe that AdBlue can be added directly to your diesel tank as a fuel additive rather than in its own tank. However this is not the case as it needs to go through the dosing control unit which mixes the ad blue with the exhaust gases at a controlled rate.Switching on the engine will cause AdBlue to run through the entire fuel system and cause extensive damage. As AdBlue flows through the system, it will corrode many metals such as steel, iron, brass, aluminium & zinc. The entire fuel system will need to be replaced. Ad blue Will crystalize when exposed to air, any signs of crystal in either your diesel tank or a fuel sample is proof of ad blue contamination. if ad blue is mistakenly added to the tank, do not turn the key, drain the tank immediately and clean with warm water. let it dry completely and if it’s free of crystals it can be used again.