Extractive Distillation Process For The Extraction Of High Purity Propionaldehyde

The production status of the propionaldehyde, the method of synthesis and the separation status of propionaldehyde were summarized at home and abroad in this paper. About the separation problems of propionaldehyde and water, researched propionaldehyde production and separation process, analyzed the advantages and disadvantages of the various separation methods, by referring to a large number of domestic and foreign literature. On the base of the previous studies, the production and the separation process of propionaldehyde was studied, the production process of the high purity propionaldehyde is proposed by using extractive distillation. The mixture of propionaldehyde and water is separated by extractive distillation, and obtained high purity propionaldehyde.On the basis of referring to relevant literature and solvent handbook,the interaction force and influence between propionaldehyde, water and solvent were studied, by analyzing the factors about the polarity, the properties and molecular structure of Propionaldehyde and water. Several extraction solvents were initially selected for extractive distillation from the twelve category solvent.The volatility of propionaldehyde relative to water was mensurated by making the experiments in the different solvents, finally, selected glycerin as the extractant of the extractive distillation.The vapor-liquid equilibrium data of the propionaldehyde-water binary system were mensurated by using the single stage gas-liquid equilibrium pot at the normal temperature, and passed the check of thermodynamics. The Interaction parameter of the system was related by using the method of the minimum variance in the Wilson, UNIQUAC, NRTL, Margules, Van Laar model, and simulation results showed that Wilson equation had the minor absolute error. According to the diagram of two phase system simulation calculation and diagram of there phase system simulation calculation, ternary VLE data were simulated and were compared with experiment data.The separation process which the extractive distillation extracts the high purity propionaldehyde was simulated by using the Aspen plus software, the conditions of simulation such as solvent ratio, output rate, and number of column plates were studied, meanwhile, researched that the different extractant had an effect on the separation process of extractive distillation, finally, the theoretic data of extractive distillation separation was gained.The experiment of extractive distillation was studied on the basis of the theoretical datas which were acquired by Using Aspen plus extractive distillation simulation software.The experiment apparatus of extractive distillation was also set up,designed and studied plates on the effect of separation. In the optimal condition,the content of propionaldehyde can was increased to 99.7%, the yield was 91.5%, extraction solvent can be recycled, reused.The solvent, the VLE data of the propionaldehyde-water binary system and the simulation results of extractive distillation in this paper provided the foundation experimental data and theoretical basis for the industrial scale, and this method and process used in extractive distillation is simple and low energy consumed.