Using BatchSep to simulate the ethanol-water batch distillation process

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write in front: I'm new to Aspen. Recently, my company has a pilot project to concentrate a 20% ethanol aqueous solution, so I looked for online information and learned how to operate it step by step. I posted this process just to learn it with everyone. * For a moment, I don’t know if this simulation result is credible (I still don’t have enough confidence in myself: lol, I don’t know if it can be used in practice), and I would like to ask the heroes to check it for me. In addition, the next step is to calculate the tower diameter and distributor, but I have no clue yet. . . . Please give me some advice, heroes! first: This is my understanding of batch distillation simulation: Given the feed composition, assuming the number of trays in the packed tower, given a heating amount (heat given by steam), set a reflux ratio, let the software (operator) operate it, and let it end when it reaches certain conditions (for example, after 3 hours, or when the substrate concentration drops to 0.5%, it can be discharged), and check the composition and quantity of each stream of materials such as the column still and the extraction at each time point. materials: 20% ethanol, 500kg/batch requirement: When the substrate concentration is below 0.5%, taking into account the energy consumption of the intermittent process, I divided the simulation into 2 stages, with the end point of the first stage: The distillate mixing concentration is increased to 90%, and the second stage increases the reflux ratio to 2 until the substrate concentration drops below 0.5%. I did a new simulation in the second stage here, and the feed concentration is the concentration of the column still in the first stage of distillation. I don’t know if there is such a function in batchsep, which can automatically adjust the reflow ratio after defining certain conditions. If so, it would be much more convenient. Unfortunately, I am not familiar with the software, so I used this stupid method. Let’s look at the process next: first paragraph: Enter the components. Select physical properties method. Don't ask me why I chose this one. I guess I didn't learn physical chemistry well. I chose it based on my predecessors. Looking at the binary interaction parameters, I actually can’t understand them either. Enter the process interface, select the BatchSep module, and connect the incoming and outgoing materials. Enter the feed status. The feed flow rate here is set to 0.5kg/h. I dare not set it to 0. I have not tried it. There is a one-time addition of ingredients at the back. Assume that the number of plates in the tower is 25. To select the heater size, I randomly filled in the size of a 3000L enamel kettle. I don’t know what it does, I guess it’s used to calculate the liquid level. The condenser here defaults to Total, which means full condensation. Set the reflux ratio. The initial setting is 1. The default here is the heating mode. I chose the heating setting of the jacket. You can choose the heating medium temperature (of course, if you choose this heating temperature, you must also set a heating area and K) and heating power. I chose a heating power of 25kW. Set the pressure drop. I estimate the gross here to be 10kPa. Set the liquid holding capacity. The unit is mass, which is based on weight. There are other units available. The following 0.7 is the liquid holding capacity of a single board. 0.7 is also my rough estimate. Set the number of distillate receiving tanks, 1 raw material added here at one time, 500kg. I follow the same pattern, I don’t know what it means, please enlighten me! Here you set the conditions for the end of distillation. You can choose how long it takes to end, or you can choose the trigger condition to end. The trigger condition for the latter I chose is: from top to bottom: Distillate receiving tank - receiving tank 1 - mass concentration of the mixture - ethanol - concentration from high to low - when the concentration reaches 0.9 mass fraction - if the above requirements are not met within 6 hours, it will end. I estimate that 6h here must meet the requirements, and it can also be set for a longer time. Once finished, you can allow the simulation and view the results.: inside time Profiles. This is the mixing concentration of the distillate receiving tank that changes with time, and finally reaches 0.9 when the distillation is completed. The concentration of the distillation column that changes with time. This is the liquid holding capacity of the distillate receiving tank. A total of more than 69kg of concentrated ethanol was received. This is the liquid holding capacity of the tower kettle. In the end, 414kg was left. This is the concentration change of the condensate. Above the clockwise value is the first stage. The reflux ratio R=1 will definitely not work. The actual operation is to increase the reflux ratio. Next, I changed it to R=2. The concentration of the tower kettle is the concentration of the tower kettle at the end of the first stage. See below for details: Write down the result of the first section, go back to the previous step and modify the concentration of the column feed, that is, change the reflux ratio of the concentration value of the column at the end of the first section to 2. The one-time feed amount, the first section is 500kg, then the second section is the liquid holding capacity of the column at the end of the first section. Modify distillation end conditions: Tower reactor - liquid phase mass separation - ethanol - concentration changes from top to bottom - ends when it reaches 0.005 mass fraction (1 is 100%). It will end if the triggering conditions are not met after 6 hours. Next run the simulation to see the results: After 2.3 hours, the ethanol concentration in the tower kettle reaches 0.5% and ends. The condenser is the timely concentration change of the distillate, the change of the mixing concentration of the distillate receiving tank, and the liquid holding capacity of the distillate receiving tank. Finally, 50kg of dilute alcohol is collected. Upload 2 simulation files, the first and second paragraphs. Please help me see if there are any problems with the above simulation. I welcome your advice! let us learn together * progress. My version is 8.4