(121g) Influence of Alcohol Additives on the Viscosity and Solubility of Ethanol/Diesel Fuel Blends: A Molecular Dynamics Simulation Study

The viscosity and solubility of ethanol/diesel fuel blends have an important influence on its application in diesel engines. Molecular dynamics simulation was employed to study the effects of different alcohol additives on the viscosity and solubility of the blends between diesel and anhydrous ethanol. Among these alcohols, n-butanol, n-heptanol and n-decanol were selected for investigating the influence of alcohol chain length on solubility and viscosity, while the effects of straight and branched chain on solubility were studied via comparing with four isomers of butanol.The results showed that the viscosity of the blends increased with the increasing of alcohol carbon number. The analysis of diffusion coefficient represented that the alcohol additives enhanced the molecular mobility and activity, and alcohols with higher carbon numbers provided a better inter-soluble capacity. It was clearly that the straight chain butanol had better miscibility than that of branched structures. The analysis of energy revealed that the hydrogen bonding interaction and Van der Walls attracting had significant effects on enhancing miscibility of blends. The present study provides fundamental understanding of the interactions for ethanol/diesel blends with co-solvents, revealing the mechanism of difference in solubility and micro behavior of diesel molecules in fuel blends.