| The shortage of oil and the increasingly serious environmental pollution were seriousproblems needed to be solved now. Many researchers were interested in low emissionalternative fuels, as an energy-saving and pollution reducing fuel, methanol-diesel emulsionhas become a hot area of research in recent years.According to Stokes subsidence law and HLB value theory, selection principles of mixedemulsifiers were discussed to filter emulsifiers using high speed disperser as dispersionmethod. The experiment studied that some factors had influences on methanol-dieselemulsion of stability and rheological property and dispersity characteristics and flash pointand condensation point and corrosion performance, whose factors contained percentages ofemulsifier and methanol and rotating speed and emulsifying time and kinds and percentagesand structures of co-emulsifying agent, so that suitable experimental conditions weredetermined. The relationship between the physical and chemical properties of emulsion wasinvestigated to get the range of critical micelle concentration. Methanol-diesel emulsioncompared with diesel in performances and economic cost to prepare emulsion which had lessdosage of emulsifier and lower economic cost and uniform size distribution and could meetthe national standards.At last we had the suitable quality ratio of emulsifier, it was m(oleic acid): m(Span-80):m(glycerin monasteries): m(Tween-20): m(Tween-80): m(sodium dodecyl sulfate)=10:4:8.5:1:1:1, HLB value was5.2. The appropriate parameters were studied, which wereappropriate parameters was3%, percentages of methanol was15%, rotating speed was5×2800r/min, emulsifying time was2min, HLB value ranged from5to6, percentages ofn-butyl alcohol was1%, on these occasions, the emulsion had bigger viscosity and lesschroma, viscosity was4.68mPa·s, chroma was2.5, flash point was57℃,corrosion to copperstandards was1b, condensation point was-8℃, these three performances did not have changes in general, emulsion appeared as proximately Newton fluids, which met the nationalstandards. According to the comparative stability result of emulsions prepared by n-alkanoland iso-alkanol, n-alkanol was better. With the increasing of content of n-butyl alcohol, at firstthe stability increased then decreased. The viscosity of emulsion increased with the increasingof the mass fraction and viscosity of emulsifier and content of methanol. When the viscosityof emulsion was the maximum, surface tension was the minimum, critical micelleconcentration of the emulsion ranged from2%to3%. Methanol particle size was increasedwith content of methanol, decreased with content of emulsifier, when rotating speed was5×2800r/min and emulsifying time was2min, methanol particle size had the optimum value.With these appropriate parameters, its Sauter droplet size was13.0μm. Compared to diesel, ifthe rate of fuel saving was10%, emulsion was cheaper than diesel per ton, which can reach200yuan in economic cost.Above all, according to advantages of methanol-diesel emulsion, so it could result toenergy conservation, and it would have an important practical significance to relief energycrisis and environmental pollution. |
