One question per week
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I think the proposal to have one question per Monday over the past couple of days was great; why hasn’t anyone discussed it lately? I’ve shared the results and am waiting for everyone’s feedback. I’m posting this again here – I hope the experts can give me some advice. The results I obtained using the simplified method are as follows; why is there such a big difference from those of the person above? Minimum reflux ratio: 2.56009012 Actual reflux ratio: 3.1 Minimum number of stages: 16.4704498 Number of actual stages: 31.6772628 Feed stage: 18.4711566 Number of actual stages above feed: 17.4711566 Reboiler heating required: 1226064.7 Btu/hr Condenser cooling required: 1224012.33 Btu/hr Distillate temperature: -28.631319 F Bottom temperature: 5.44463458 F Distillate to feed fraction: 0.7285479 I set the ethane content at the tower top outlet to 0.01; the reflux ratio obtained through design calculations was 3.6. When the ethane content was changed to 0.001, the reflux ratio became 8.0.
It can be calculated using radfrac; please send the detailed problem so that everyone can take a look. Thank you
It has already been posted by someone else, so I’m reposting it here: Here is the link to the question: http://bbs.hcbbs.com/thread-352330-1-2.html The question is as follows: In the example related to the deethanizer, the feed conditions are as follows: Pressure – 18 bar; Vapor fraction – 0; Composition on a molar fraction basis: HYDROGEN – 0.00014, METHANE – 0.00162, ETHANE – 0.24003, ETHYLENE – 0.75746, PROPYLENE – 0.00075; Total molar flow rate – 100 lbmol/hr. The operating conditions are: Reflux ratio – 3.1. Light key: Ethylene recovery rate – 0.95; Heavy key: Ethane recovery rate – 0.03. Condenser pressure – 17.8 bar; Reboiler pressure – 18.2 bar