The first results from the fuel tests have now been published in an article in the journal FUEL. As a representative of the group of poly(oxymethylene)ethers that are to be produced in the SynergyFuels project, butylal was tested at the TFZ for its suitability as a diesel substitute or blending component in fossil or paraffinic diesel fuel. Many important fuel properties of six blending stages were analysed and evaluated based on the current diesel standards for European diesel according to DIN EN 590, American diesel according to ASTM D975 and HVO diesel according to DIN EN 15940. In addition, the use of two additives was tested to improve the oxidation stability and lubricity of pure butylal.
Pure Butylal does not fulfil the requirements of the fuel standards EN 590, ASTM D945a, EN 15940 and DIN TS 51699, which means that it is not compatible with existing engine technology. However, the addition of butylal improves the cetane number of fossil diesel fuels. The disadvantageous fuel properties are the low calorific value and the hygroscopic properties of butylal. However, the poor lubricating properties and oxidation stability can be improved with the additives tested in the study.
The results show that up to 30 % butylal can be added to diesel fuels as a climate-friendly blending component. The use of renewably produced butylal in fossil diesel fuel would not only be more climate-friendly but would also improve the ignition behaviour of the fuel blends. However, further investigations into the material compatibility and storage stability of fuel blends with butylal are necessary to assess their suitability for existing engine technology.
The open-access article is available at the following link: https://www.sciencedirect.com/science/article/pii/S0016236125008026