AdBlue®

AdBlue® is an aqueous urea solution consisting of 32.5 mass% pure urea and demineralized water. It is used to reduce nitrogen oxide emissions from diesel engines in vehicles. The solution is non-toxic and has been internationally standardized.

Definition of AdBlue® 
AdBlue® is a specific AUS (Aqueous Urea Solution) 32 used as an environmentally friendly technology to reduce nitrogen oxide emissions in diesel engines. It is injected through a dosing unit upstream of an SCR catalytic converter to enable the conversion of nitrogen oxides into nitrogen and water.

Background / Origin
AdBlue® is the brand name protected by the German Association of the Automotive Industry (VDA). The compounds that make up AdBlue® are produced using a chemical process. The solution has been used since the introduction of the Euro 4 and Euro 5 emissions standards in order to comply with the strict environmental protection regulations. AdBlue® is part of the imposed standards in many regions, being known as Diesel Exhaust Fluid (DEF) in North America and Arla 32 in South America.

The technology has continued to evolve, with an increasing number of cars and trucks being fitted with SCR catalysts to reduce emissions. The development of the AdBlue® infrastructure includes the provision of pumps at filling stations in Europe since 2020.

Properties
AdBlue® has the following key properties:

- Composition: AdBlue® consists of 32.5 mass% pure urea and demineralized water.
- Physical characteristics: The solution is colorless, odorless and non-toxic.
- Chemical characteristics: AdBlue®  is injected at high pressure into the exhaust duct by a metering pump, where it is converted into ammonia via an intermediate step.

The addition of urea makes it possible to reduce nitrogen oxide emissions by up to 90% in conjunction with SCR catalytic converters.

Application and importance in the market
AdBlue®  is predominantly used in diesel vehicles and is crucial for compliance with exhaust emission standards. The use of SCR technology makes it possible to significantly reduce nitrogen oxide emissions by injecting AdBlue® into the exhaust gas stream. The consumption of AdBlue® is between 2% and 8% of diesel fuel consumption.

AdBlue® is produced by around 150 manufacturers worldwide, which ensures broad availability, even with increasing sales. The VDA study shows that around 20 million diesel vehicles with AdBlue® technology should be in operation in Europe by 2020.

Differentiation from similar terms
AdBlue® differs from other urea solutions in that it was developed specifically for use in SCR systems. In contrast to Diesel Exhaust Fluid (DEF), the term AdBlue® is protected by trademark law and refers to a precisely defined formulation.

Summary of the product
AdBlue® is a standardized aqueous urea solution used to reduce nitrogen oxide emissions in diesel engines. With a composition of 32.5% urea and demineralized water, it is integrated into vehicles via SCR catalytic converters. The solution contributes to compliance with strict emission standards and has established itself as a widespread technology in the vehicle market. In addition, AdBlue® is produced by numerous manufacturers worldwide, which ensures solid availability.