摘要 |
A process and apparatus for efficiently and economically separating organic chemicals, that have an affinity for water and carbon dioxide, from water using liquefied carbon dioxide extraction. A secondary reboiler with external heating capacity improves the separation of carbon dioxide, for reuse, from extracted organic compounds. The secondary reboiler comprises a boiler heated by an external heat source, such as steam. The secondary reboiler is fed liquid from a primary or vapor recompression reboiler and returns vapor to the primary reboiler. Addition of the secondary reboiler permits the primary vapor recompression apparatus to be operated at a lower temperature and to use the recompressed still overhead vapors for heat. Secondary heating provided by the secondary reboiler improves separation by providing an additional equilibrium stage of separation, thus the stream drained from the secondary reboiler has a much lower concentration of the extractant fluid.
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