ISO 22241 Diesel Engines — NOx Reduction Agent AUS 32 — Quality Requirements

ISO 22241 is an international standard that specifies the quality characteristics of the NOx reduction agent AUS 32, commonly known as Diesel Exhaust Fluid (DEF). This aqueous urea solution is essential for the operation of selective catalytic reduction (SCR) systems in diesel engines. The standard outlines the requirements for the purity, concentration, and physical properties of AUS 32 to ensure its effectiveness in reducing nitrogen oxide (NOx) emissions from diesel engines. Key parameters include urea content, alkalinity, biuret, aldehydes, insolubles, and trace elements such as phosphorus and calcium.

The purity and concentration of AUS 32 directly affect the efficiency of SCR systems in converting NOx into harmless nitrogen and water. Impurities such as phosphorus and calcium can lead to the formation of deposits in the SCR catalyst, reducing its effectiveness and lifespan. Accurate determination of these parameters ensures that AUS 32 meets the required specifications for optimal performance and environmental compliance.

The methods specified in ISO 22241 are important because they provide standardized procedures for the precise and reliable measurement of AUS 32 quality characteristics. Techniques such as refractive index measurement for urea content and inductively coupled plasma optical emission spectrometry (ICP-OES) for trace elements ensure high sensitivity and specificity. By providing detailed guidelines for quality control, ISO 22241 helps manufacturers produce AUS 32 that meets regulatory requirements and supports the reduction of NOx emissions from diesel engines.

With the highly robust and sensitive PlasmaQuant 9200 series, Analytik Jena offers a powerful, reliable and compliant solution for ICP-OES analyses to fulfill the requirements of ISO 22241.

Sources

• ISO 22241 - Diesel Engines — NOx Reduction Agent AUS 32 — Quality Requirements