Research On Technology Of Separation Of Vitamin E From Deodorized Distillate

The thesis studies the technologies of separation of natural vitamin E from deodorizer distillates of soybean oil (SODD) by the new extraction technology that methyl esterification of free fatty acids, molecular distillation and adsorption resins.The content of free fatty acid in the SODD is high so methyl esterification of free fatty acids would be done fristly. The effect of the solvent-to-SODD ratio, the catalyzer-to-SODD ratio, esterification temperature and esterification time on the esterification rate of free acid is analyzed with the acidic exchange as solid acid catalyst and zeolite as eliminator respectively, and the optimum esterification conditions are found that the solvent-to-SODD ratio is 1.6, the catalyzer-to-SODD ratio is 0.2, esterification temperature is 60℃, esterification time is 5 hours, with the esterification rate 97.12%.Molecular distillation of vitamin E between from SODD and from methyl esterification products are conducted in comparison, and distillation of vitamin E from SODD is employed. Provided the conditions that distillation temperature 150℃and feed rate 6.45ml/min and the conditions that distillation temperature 170℃and feed rate 11.52ml/min, tocopherol contents in the residue are showed to 16.4% and 18.3% respectively, which are 5.5% and 7.4% higher than that in SODD. Then esterified product is separated by three-stage molecular distillation, and response surface methodology is introduced to conduct the third-stage distillation experiment, and is analyzed to find the prefered conditions that distillation temperature 208℃, feed rate 8.50 ml/min and agitating speed 206rpm, and get tocopherol content 54.49% and recovery rate is 95.74%. And then an experiment is done to validate the conditions.In order to gained higher content of VE, the static adsorption of the resin is discussed primarily. The adsorption equilibrium of tocopherol in the distillate on strong alkali exchange resin is obtained with ethanol as solvent by static method, and the saturated adsorption amount, 464.68mg tocopherol/g dry resin and 373.97mg tocopherol/g dry resin is got at 25℃and 35℃respectively.