Improved test method to help predict diesel winter performance

The Energy Institute (EI), based in the UK, has been working to improve the test methods for predicting winter performance of diesel fuels, particularly those containing significant amounts of biodiesel.

EI claims one important winter performance parameter is the ‘cold soak’ filter blocking tendency of the fuel.

‘The existing EI test method is IP PM-EA/08, ‘Determination of filter blocking tendency of fatty acid methyl esters – cold soak and filtration method’. The test method comprises of a sample pre-treatment step which involves warming the sample to 60°c (in order to remove its thermal history) before the cold soak,’ reads a statement.

‘During the cold soak the sample is chilled to 5°c and held at this temperature for 16 hours. After the cold soak the filter blocking tendency is determined using IP 387 Procedure B.’

The cold soak filterability test was further developed after a joint workshop between the EI and European Committee for Standardisation (CEN) Working Group 31 (WG31). Recent work by WG31 has targeted sources of variability in the procedure and a draft CEN method has been developed.

The EI has now incorporated all of the recent developments and enhancements into an updated proposed method - IP PM-EA/13. Enhancements to the method include changes to the sample preparation step and cold soak apparatus and the introduction of a verification standard. 

This winter IP PM-EA/13 is being used by the fuels supply industry and other interested parties to feedback performance and user experiences to ensure the method is robust and fit for purpose. This will enable WG31 to further optimise the draft CEN test method. A precision study could then take place in 2014.