Skalar's PRIMACS™ SNC-100: Precision Urea Measurement for ISO 22241 Compliance in AdBlue

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AdBlue is a DEF (Diesel Exhaust Fluid), also known as AUS32, which assists in reducing harmful nitrogen-oxide emissions that are produced by diesel engines. AdBlue is added to a separate tank on trucks, busses, ships and cars with modern diesel engines, using a catalytic convertor. These catalytic reduction systems are very sensitive to impurities or contaminations in AdBlue, potentially leading to damage or downtime of these systems.

Therefore, the urea content in AdBlue must comply with an exact specification. ISO 22241 specifies that it must be checked that every produced batch of AdBlue must have a Urea content of 32.5% of urea (min 31.8% - max 33.3%)

The amount of urea in AdBlue can be measured with a refractive index method or via combustion. Skalar has developed the measurement of urea through combustion further on the PRIMACS™ SNC-100 TOC/TN analyzer as this method gives the total result of the amount of urea immediately and the refractive index is a comparison measurement technique.

The PRIMACS™ SNC-100 analyzer determines the amount of urea by measuring the total nitrogen content in AdBlue through combustion of the sample in pure oxygen at 1100 °C.

The nitrogen is converted into NxOy in the presence of oxygen. In the reduction furnace all nitrogen is reduced to N2 . The N2 gas is measured by the Thermal Conductivity Detection (TCD). The Skalar analysis method is according to ISO 22241.

For more information about the above application or TOC/TN analysis in other matrices: