Study On Batch Distillation For High Purity Methanol

With the rapid development of high and new technical industry, high purity methanol has got more and more extensive applications in the fields of chemical industry, pharmacy, analysis testing, electronic cleaning and so on , and the demand quantity of market is continuously rising. At present, high purity methanol is baddish, and also the technical route is short of competition inland. However, its market depends on import to a large extent. Utilizing industial methanol to make high purity methnol which has high additive value and ample source of material has very important significance for filling with the vacancy of producing high purity methanol independently.Firstly, in my paper,the equipment of batch distillation was used,raw material from the sourse of natural gas which had high quality relatively was chosen to make high purity methanol through analyzing the testing results of three different sources of methanol inland;Secondly, constant-molar-holdup model of batch distillation for high purity methanol was proposed and solved by the two-point implicit combined with component balance calibration. Some kinds of effect factors on recovery fraction of high purity methanol were simulated, such as reflux retio, theoretical plates stages, holdup slop, cut withdrawal,etc. As the simulating results showing, when the composition of raw material was 98%, and the average purity specification of high purity in top of column was above 99.9%, the feasible number of theoretical plates was 35, the reflux retio of product phase and slop cut withdrawal respectively were 5 and 10, and the proportion of the outpu of slop cut withdrawal was 15%. Accordingly, the single recovery fraction of high purity methanol was between 50% and 65%. Thirdly, in order to testify the veracity and reliability of the model mentioned above, the raw material of methanol from natural gas was used to experiment for the process of batch distillation. The experimental result was relatively closed to the simulating result., the scope of error was below 10%, which showed it preferable veracious and feasible that constant-molar-holdup model was used to simulate the process of batch distillation for high purity methnol. Finally, on the basis of the results of experiment and simulation, the best technology route was got: the number of theoretical plates was 34, the reflux retio of product phase and slop cut withdrawal respectively were 5 and 10, and the proportion of the output of slop cut withdrawal was 15%. Accordingly,...