The use of biodiesel blends in domestic vaporising oil burners

Biodiesel is receiving increasing attention as a partial substitute for home heating oil. The properties that make it a suitable fuel for use in diesel engines also make it suitable for heating systems using pressure jet burner technology. In the UK, however, there are a significant number of vaporising burners whose suitability for operation with biodiesel has not been properly studied. The purpose of this study was therefore to investigate the use of different blends of biodiesel and kerosene in a production Aga that employed a sleeve-type vaporising burner. It was found that significant fouling of the burner well would occur within a short period of time, even with a blend as low as 5% by volume of biodiesel in kerosene. Further investigation revealed the build-up to consist of polymerised biodiesel, most likely triggered by heat. Factors contributing to the rate and extent of fouling are thought to include the type of vegetable oil used as feedstock for the biodiesel, as well as the degree of prior utilisation of the feedstock oil. Further investigation is warranted, possibly with the use of suitable fuel additives to inhibit the polymerisation process.