Studies On Synthesis And Purification Of Medium-chain Triglycerides

The author synthesized glycerides with medium-chain fatty acids and glycerol,using phosphotungstic acid on carbon as a catalyst。The highly pure medium-chain triglycerides was attained by physical refining。The studies on analysis of the product shew GC analysis had better stability and recurrence。Column temperature was set 100℃ for 1 min and was programmed at 16℃/min to 260℃,then 10℃/min to 330℃,last at 5℃/min to 370℃。Results of study on different catalyzers shew phosphotungstic acid was the best catalyzer。Conversion and selectivity of MCT amounted to 82 percent and 68 percent,respectively。The technics of phosphotungstic acid adsorbed on carbon indicated circumfluence adsorption Technic was better than others。In this way,phosphotungstic acid was more stable in esterification reaction。Phosphotungstic acid / carbon mass ratio was the primary factor。The more adsorption quantity,the stronger catalysis was。 Appropriate adsorbing conditions were phosphotungstic acid / carbon mass rate of 30 percent,temperature of 70℃,reaction time of 6h。Adsorption quantity amounted to 20.8 percent。The appropriate activation temperature was 180℃。Kinetic profile of MCT forming revealed it came into being in second half time。 Under the optimum reaction conditions: the catalyst`s quatity of 4 percent of glycerol,reaction temperature of initial 140℃ and last 160℃,the ratio of acid/glycerol of 3.22/1,reaction time of 90min,residual pressure of 9000Pa,the Conversion and the selectivity of MCT amounted to 85 percent,75 percent, respectively。What`s more,after simply done with,the catalyzer could be reused four times。Technique of refinement of MCT with three-step molecular distillation was studied. By controlling feed materiel quantity,pressure and temperature,high pure MCT and Medium-chain partial glycerides were attained。The optimum operating conditions were that in the first-step molecular distillation the feed materiel quantity was 1.6 L/m2h, pressure,1.5Pa,temperature,110℃。 In the second-step molecular distillation,the feed materiel quantity was 1.6L/m2h, temperature,165℃, pressure,1.5Pa。In the last-step molecular distillation,the feed materiel quantity 1.2 L/m2h,temperature,270℃, pressure,1Pa。Content of MCT amounted to 97 percent。...