Study On The Separation Of Methanol-Acetone Binary Azeotrope Using Extractive Distillation

A relatively complex azeotrope of methanol-acetone with boiling temperature very close to that of the more volatile compound in the system(acetone) was studied using the extractive distillation in this dissertation. It is an important part of the separation process, which gains the varieties of the organic materials from the by-product in water of Fischer-Tropsch synthesis of the Shanxi academe in liquefying coal. With the exploitation of technology in liquefying coal to synthesize oil, the separation of the by-product in water is a problem solved urgently, which is significant to the environment and the economy of the liquefying coal process.Due to the methanol-acetone binary system shaping the azeotrope, the extractive distillation was adopted to separate them. Firstly the solvent water was selected from many solvents by the fuzzy mathematics. Secondly, through the simulation of the ASPEN PLUS software, the results were used to direct to set up and operate the distillation columns. Thirdly the optimal parameters were obtained by adjusting all parameters of each column in a lot of experiments. At last, the reliability of the model was proved by means of comparing the results of experiments and those of the simulations.Through the experiments and simulations of the extractive distillation column and the solvent recovery column, the optimal parameters gained are as follows. (1) The extractive distillation column: the column is 20 theory stages and the solvent and the feed stage are respectively 6 and 13(from up to down); the ratio of solvent to feed is 3, the reflux ratio 6 and the distillate ratio(D/F) 0.166kg/kg. (2) The solvent recovery column: the equipment parameters: the column is 14 theory stages and the feed stage is 10(from up to down); the operating parameters: the reflux ratio is 3 and the distillate ratio(D/F) is 0.217kg/kg.UNIQUAC thermodynamics model is considered as the optimal model in the simulation of two columns(the extractive distillation column and the solvent recovery column) by model check. The separation process was simulated and optimized using the model, whose results can be used in designing and directing production.