| 摘要 |
PROBLEM TO BE SOLVED: To recover a highly volatile fluorine compound using cryogenic rectification by feeding the highly volatile fluorine compound into a cleaning liquid, producing a highly volatile fluorine compound in a third rectification column from a second top fluid separated in a second rectification column from a first bottom fluid separated at a first rectification column through cryogenic rectification and then recovering the highly volatile fluorine compound. SOLUTION: Cleaning liquid containing a highly volatile fluorine compound and a low volatile fluorine compound is extracted, as a flow 22, from the lower part of a cleaning column 9 and combined with the liquid fraction 7 of supply material to produce a flow 23 being fed to the intermediate section of a first rectification column 24. The flow 35 of a first column bottom liquid separated through cryogenic rectification is fed to a second rectification column while the flow 39 of second column top vapor is fed to a heat exchanger 12 to produce a liquid flow 40 which is fed as a return flow 41 to the top of the second rectification column on one part and fed to the upper part of the cleaning column 9 on the other part. A liquid containing a highly volatile fluorine compound is transported from a batch type storage tank 32 to the reservoir of a batch column 44 which operates to separate the mixture of highly volatile fluorine compound into fractions of refined products.
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