Experimental Investigation of Multi-Component Emulsion Fuel Stability

Abstract

The emulsification of water with liquid fuels to modify combustion characteristics has been of great interest to the combustion research community for some time. The emulsions are usually comprised of only water combined via ultrasonification (or other mechanical methods) with a base hydrocarbon fuel. These emulsions show improved combustion characteristics, such as lower combustion temperatures, and lower emissions. One of the main issues with these emulsions, however, is that these emulsions are not stable and are prone to phase separation over time, which inhibit the economic viability and practical application of these fuels. There are a multitude of ways being researched to improve fluid stability, including new mixing techniques, the addition of nanoparticles, as well as the addition of other fluids. The addition of ethanol to water-based emulsions has been shown to decrease the size of water droplets in the emulsion, allowing for a more homogenous mixture. With the aviation industry being a sizeable source of the global emissions caused by transportation, methods of lowering the emissions of aviation fuels as well as greener alternatives are needed. Present research quantitatively studies how the addition of ethanol to water and jet fuel emulsions affects the stability of the emulsion. A non-invasive, quantitative, and economical method for determining phase separation is used to study the stability of these multi-component mixtures. The system periodically measures the phase separation of the fluid column by automatically shining light through the fluid and detecting how much interference is created by the fluid. The system does this at five different depths of the fluid so the phase separation of the emulsion can be tracked in more detail. Ethanol and water are studied at mixtures of 5%, 10%, 15%, and 20% ethanol by weight and 5% and 10% water by weight emulsified with jet fuel. It is expected that the present research will lay additional foundation for the future study of fuel emulsion stability, as well as spark additional interest in utilizing emulsions to improve fuels.