Please take a look, it’s a chemCAD issue related to three-component distillation
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I’m using the latest version 6.2; the flowchart has been drawn as shown, and the units have been corrected. SRK is being used, and all three components have been added to the list: benzene, toluene, and isopropylbenzene. The feed stream is defined as shown in the figure. The column is configured with 19 theoretical plates, with the feed plate being the 10th one; the specified parameters are indicated in the figure, and no other settings have been changed. But it can’t run. Hint: The feed streams are not well defined. Calculation has been skipped. I don’t know why; it’s confusing. Additionally: the conditions are an operating pressure of 101.3 KPa, a feed rate of 100 Kmol/h, with saturated liquid as the feed; the composition is as shown in the diagram, namely 0.25, 0.35, 0.4. The required recovery rate for toluene in the distillate is 0.98, while the recovery rate for isopropylbenzene in the bottom stream is 0.96. Thank you so much. . . .
I tried it with ChemCAD 6.2.0; for the Feed Stream, two of the three values—T, P, and Vapor Fraction—need to be set. Once you have P = 101.3 KPa, you also need to set Vapor Fraction to 0 in order to carry out the calculation. Calculation results: CHEMCAD 6.2.0 Page 1 Simulation:Untitled Date: 06/11/2010 Time: 10:13:55 FLOW SUMMARY: Stream No. 1 2 3 Stream Name Temp K 382.3219 368.7486 424.5029 Pressure Pa 101350.0000* 101350.0000 101350.0000 Energy content MJ/h 1598.7 2266.1 -381.31 Vapor mole fraction 0.00000* 0.00000 0.00000 Total kmol/h 100.0000 60.8997 39.1003 Total kg/h 9985.5446 5305.5743 4679.9707 Total standard liters m3/h 11.4571 6.0553 5.4018 Total standard cubic meters m3/h 2241.36 1364.98 876.38 Flow rates in kg/h Benzene 1952.8500 1952.8263 0.0237 Toluene 3224.9348 3160.4367 64.4982 Isopropylbenzene 4807.7602 192.3112 4615.4490