ASTM International’s committee on petroleum products, liquid fuels, and lubricants (D02) has approved a new standard for a renewable bio-based blendstock that can be used as a diesel alternative. The standard, ASTM D8181 covers specifications for microemulsion blendstock for middle distillate fuels.
“This new standard is needed because there is no relevant existing standard for this type of chemistry,” says Kristin Aramthanapon, technical advisor at Sylvatex, Inc. She adds that these specifications will be used by manufacturers and customers to ensure that the material being produced and used meets quality and consistency measures while also correlating with vehicle performance to fuel properties.
The ASTM D8181 specification describes an alcohol-carboxylic acid blendstock which is to be blended with fuel oils to produce a microemulsion of inverse micelles. The microemulsion blendstock is to be blended with fuel oils to produce a microemulsion test fuel oil that is intended for testing and demonstration purposes in specialty applications such as compression-ignition engine and burner fuel applications.
Typical fuel oils that could be used for blending with microemulsion blendstock are fuels that comply with ASTM D975 and D396 and may contain up to 5 % by volume biodiesel.
Testing with test fuels containing 10 % microemulsion blendstock using B5 as a base fuel did not show any detrimental changes to specified fuel properties relative to B0 base fuels, but can impair measurement of microemulsion blendstock concentration.
The microemulsion test fuel oil (to be made from this blendstock) is to be used for demonstration purposes only in specific equipment and vehicles that are suited for use with low flashpoint fuels and oxygenated fuels such as ethanol.