ISO Paraffinic Diesel Fuel Lubricity Study

An ad hoc working group (WG) “AG1” was formed by ISO/TC22/SC34 [1] to conduct the necessary research to mitigate concerns with the prediction of lubricity in paraffinic diesel fuel (e.g., renewable diesel [RD] and gas-to-liquids [GTL] fuel), using ISO 12156-1 [2] high-frequency reciprocating rig (HFRR). Several field complaints had been raised regarding anomalies with HFRR readings of RDs not accurately predicting the lubricity of the fuel. Specific reports include readings below the 460 μm wear scar diameter (WSD) limit may still allow excessive scuffing and wear. Generally, for all fuels, there is a deterioration in precision (measurement error) in the 350 μm-500 μm range.

The Paraffinic Diesel Fuel Lubricity AG1 was given the mandate to execute its work tasks comprising the below-listed deliverables while embracing the concept of continuous improvement.

• Conduct a situation analysis to identify concerns, assess their impact, and codify the next steps as related to predicting the lubricity of paraffinic diesel fuels.
• Design, develop, and execute test programs to validate the suitability and effectiveness of the ISO 12156-1 and ISO 12156-2 international standards for use with paraffinic diesel fuels.
• Document the work product of AG1 by publishing an SAE Technical Paper which shall refer to SAE Technical Paper No. 952372 [3]. The SAE Paper shall include recommendations to standards development bodies with any revision proposals to the applicable test methods or limits.

This paper provides a summary of the two-year research and development program conducted by the AG1 experts including the conclusions leading to revision proposals to the precision statements in ISO 12156-1 and ASTM D6079 [4].^*