The investigation of lecithin and cocamide DEA Biosurfactant concentrations on emulsified biodiesel fuel stability, properties, and the micro-explosion phenomenon

Water-in-diesel emulsion (WIDE) fuel has been employed to reduce the emissions from diesel engines. Emulsified fuel in combustion chamber experiences secondary atomization, leading to micro-explosions that lower the combustion temperature and improve atomization. As a result, it reduces emissions and improves combustion efficiency. Emulsified fuels often face challenges with water separation over time; therefore, chemical surfactants have traditionally been used to prevent water separation from emulsified fuel. While biosurfactants offer a more environmentally friendly option compared to traditional chemical surfactants, there is a research gap regarding use of emulsified fuel with biosurfactant. This study aims to investigate the effect of biosurfactant concentration on emulsified fuel properties, stability, particles size, and microexplosions. In this study, six emulsified biodiesel fuels were developed with 10 % distilled water and biosurfactants (lecithin 63 % and cocamide DEA 37 %) ranging from 0.5 % to 3.0 %. The emulsion stability and properties of these fuels were examined. Further, Microscopy was employed to examine particle sizes distributions and suspended droplets hot plate technique with high-speed camera was used to record the micro-explosions. The results illustrate increase in biosurfactant concentration in emulsified fuel increases density and viscosity while reducing surface tension, droplet size, and micro-explosion peak temperature.