Effects of Different Surfactant and Furan Cosolvents on the Macroscopic and Microscopic Properties of Ethanol-Diesel Fuel Blends

Ethanol is considered a clean, cost-effective, carbon-neutral fuel. In this study, the effect of a surfactant (Span 80/Tween 80) and cosolvent (furan) on the macroscopic and microscopic mutual solubility characteristics of diesel-ethanol blending were assessed. At the macroscopic level, the study investigated the impact of compound emulsifier proportions and ethanol volume ratio on the stability of the diesel-ethanol fuel. At the microscopic level, the conductivity and particle size of the blended fuels were analyzed. Additionally, fuel properties such as lower heating value, viscosity, and price per unit volume of fuel were investigated. The results indicated that Span 80 and furan were more effective in enhancing the mutual solubility of diesel and ethanol, reducing the maximum dosage by 98.55% and 92.24% by volume, respectively. Besides, compared with furan-diesel-ethanol, emulsifiers increased the conductivity of the mixture by two orders of magnitude. Furthermore, the lower heating value (LHV) of microemulsion produced by Span 80 showed the LHV closest to that of diesel and the cost was even cheaper. Considering the effectiveness of cosolvents and surfactants in stabilizing diesel-ethanol blends and their resulting fuel properties, diesel-ethanol-Span 80 stands out as a promising option for diesel engine applications, showcasing the renewed relevance of traditional emulsifiers in diesel-ethanol blends.