Process Simulation And Design Of Synthetic Vitamin E Distillation Device

In the 21st century, the domestic vitamin E market grows steadily, because the nutritional additives in various fields are widely used. But synthetic vitamin E, i.e. vitamin E acetate, is a heat-sensitive material, and the property of impurity is similar. Therefore, the separation is very difficult and the domestic technology is difficult to meet the requirements of food grade and pharmaceutical grade.This paper presents a new purification process of vitamin E acetate, which is high vacuum sidedraw distillation process. Vitamin E acetate can be purified to 99%. Compared to conventional molecular distillation process, the advantages of this new process are the high purity and low energy consumption. Firstly, the simple steady-state simulation of distillation is established with SHORTCUT model in PRO/II. After obtaining the preliminary process parameters, the rigorous steady-state simulation of distillation is established with DISTILLATION model. The optimal process parameters are got by optimizing the location of side-stream and reflux flow rate. The steady-state simulation is exported to check the hydraulics of the distillation column. Then the process is confirmed and 3 columns are used. Sidedraw is designed in two columns, which can reduce energy consumption. Because of the high vacuum, Sulzer BX PLUS packing and the falling film reboiler are necessary to reduce the pressure drop of the whole column as much as possible.The plant of 6000 t/y vitamin E acetate was established in 2013 according to this process. The key parameters that are measured actually and the simulation data are very close. Thus it has proved the reliability of the process design model and calculation method.