Study On The Prescription And Preparation Of Microemulsified Diesel Oil

In this paper, some excellent diesel oil microemulsions, which were composed by oleic or naphthenic surfactant and alcohols, were successfully prepared by the method of self-emulsification. The best presceiption was ascertained by stduying the influence of cosurfactant and inorganic salt. The effect of surfactant's chemical structure on microemulsion was studied. It was found that the hydrophile group, lipophilic group and counterion had different influence on the formation of microemulsion.In the diesel oil microemulsion, which was prepared by using monoethanolamine oleate as surfactant and several kinds of alcohol with different length of aliphatic chain were used as cosurfactant, the effects of mass ratio of alcohol to surfactant and kinds of alcohol were discussed. Particle size of microemulsion with different alcohol was characterized and standard free energy change(△Gc→iθ)for alcohol to transfer from continuous phase to interfacial membrane was calculated. The microemulsion systems could be formed just when the alcohols which had more than 3 carbon atom numbers. The maximum water content, alcohol content in the interfacial membrane and average particle diameter of microemulsion systems decreased with the increase of the length of aliphatic chain of alcohol. The linear relationships existed between△Gc→iθand the carbon atom number of alcohol. The result indicated the optimum conditions was that the length of aliphatic chain was 8, the mass ratio of alcohol to surfacatant was 0.6, and the value of HLB was 8.5.The viscosity, flash point, freezing point, particle size and stability of microemulsions which were prepared by oleic and naphthenic surfactant were measured. The difference of physical and chemical properties between diesel oil microemulsion and pure diesel oil was analysed. It was found that the diesel oil microemulsion had a higher viscosity. The flash point was relate to the kind of alcohol. The microemulsion prepared by oleic surfactant had a smaller particle size and higher stability than the microemulsion prepared by naphthenic surfactant,so oleic surfactant had a better emulsifying effects than naphthenic surfactant.