Study on Properties and Construction of Diesel Microemulsions Based on Biosurfactant
|Keywords||biosurfactant diesel microemulsions cosurfactant n-alcohols|
In this paper, diesel microemulsions were formed by tration with rhamnolipid(RL, a biosurfactant) as surfactant and five normal alcohols (butanol, pentanol,hexanol, heptanol and octanol) as cosurfactant. The Critical Micelle Concentration(CMC) of the two reverse-micellarmicroemulsions, which were composed by AOTsurfactant and rhamnolipid biosurfactant, can be measured by fluorescence probe. Theeffects of surfactant and cosurfactant on the content of the max solubilization water(W0) of the constructed diesel microemulsions are investigated. The best presceiptionwas ascertained by studying the influence of the content of surfactant. And theappropriate alcohol was ascertained by stduying the influence of cosurfactant. Theeffect of ionic strength on the diesel microemulsions were also investigated bysuperseding the hyperpure water with NaOH solution. Moreover, the kinematicviscosity (μ) and interfacial tention (γ) of diesel microemulsions formed underdifferent conditions were characterized.Experimental results showed that the CMC of the two surfactant systems are asfollow: AOT:5g/L, RL:7g/L. When the mass ratio of surfactant to diesel (Km) andthe mass ratio of cosurfactant (heptanol) to surfactant (δas) were set at0.02and0.1respectively and the mass fraction of NaOH solution was0.06%, the γ and μ of dieselmicroemulsions were smaller and the W0was the highest, which suggested that theobtained diesel microemulsions had superior performance under above conditions.At last, seven typical indexes of petroleum products as follow: density, viscosity,sulfur content, conductivity, pH, particle size and stability were measured.Furthermore, with comparing the results between diesel microemulsions and0#diesel,the feasibility and superiority of diesel microemulsions were analysed as a productsubstitute for fuel.The optimizd experimental conditions have a certain value to aim at theconstruction of diesel microemulsions based on biosurfactant. And it provided thetheoretical basis for further actual application of constructing diesel microemulsionswith biosurfactant.