| The preparation of natural tocopherols is further investigated on the basis of the work that has been done by the National Laboratory of Secondary Resources Chemical Engineering.Study the effect of water content in solvent (ethanol) on the adsorption capability to improve the traditional process. Adsorption breakthrough curves were obtained, which were determined on an adsorption column of inner diameter 2.0 cm, resin packing height 25 cm. The effects of temperature, tocopherol concentration and flow rate on adsorption breakthrough curves have also been studied when ethanol and 95% ethanol were used as solvent. The results indicated that the water content in ethanol had great influence on the adsorption process. The optimum operation conditions were as follows: temperature 40℃, tocopherol concentration 50 mg/ml, flow rate 1～1.5 BV/h when ethanol was used as solvent; and temperature 40℃, tocopherol concentration 60 mg/ml, flow rate 1～1.5 BV/h when 95% ethanol was used as solvent, respectively.Study the regeneration technology of adsorption resin, the results as follows can be obtained: the best solvent is methanol and it is difficult to use only one solvent in the process when methyl estenfication products used as raw materials. It is potential to use single solvent when 50% tocopherols used as raw materials.The new process of preparation of natural tocopherols by using the mixed solvent methanol and hexane (10:1) has been studied. The optimum operation conditions were as follows: methanol /hexane (10:1), temperature 40℃, concentration 1 g/10 ml, the maximal load 15 g 50% tocopherols materials/ 94.2 ml resin. The α -tocopherol can also be obtained by adsorption process or extraction and the specific rotation of product is 30.27°, which is higher than the product made by transformation.
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