Equilibrium and hydrodynamic studies of water extraction from fermentation broth /
Previous studies using tertiary amines to extract water from reagent-grade carboxylate salts (calcium acetate, propionate, and butyrate) have shown selectivity for water and not for the carboxylate salts. These results allow the design of an extraction system to concentrate fermentation broth from a...
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| Format: | Thesis eBook |
| Language: | English |
| Published: |
[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | Link to OAKTrust copy |
| Summary: | Previous studies using tertiary amines to extract water from reagent-grade carboxylate salts (calcium acetate, propionate, and butyrate) have shown selectivity for water and not for the carboxylate salts. These results allow the design of an extraction system to concentrate fermentation broth from a mixed culture of acid-forming microorganisms. To design the extraction system, equilibrium data from amine and actual fermentation broth systems were obtained. These data are similar to the data found previously for reagent-grade pure components. The data were manipulated to obtain graphs for the Ponchon-Savarit procedure used to design multi-stage extractors. Different cases were studied in which the feed was varied. A 3.8 wt% solution could be concentrated to 17.5 wt% using five countercurrent stripping stages; however, the recovery of carboxylate salts was poor (68 wt%) with this design. To overcome this, a reflux stream and an enriching section were employed. The Janecke procedure was followed to determine the member of equilibrium stages for the skipping and the enriching sections and their operating conditions. For this case, eight stages (two enriching and six stripping) were required to concentrate the carboxylate salts from an initial concentration of 3.8 up to 20 wt%. The salt recovery was 91%, the amine:water ratio was 2.5:1 and the reflux:feed ratio was 2.4:1. This design gives good results and will be implemented in a pilot plant. To study the separation of the organic and aqueous phases, a bench-scale mixer/settler extraction tank was designed and constructed. This apparatus had three sections: a mixing section to blend the two phases, a coalescence section in which the amine and water phases coalesce, and a decanting section in which the liquids completely separate. Several experiments were made to determine the hydrodynamic properties of the mixer/settler. The experiments showed that the apparatus is suitable to perform liquid-liquid extraction. Independent experiments were made using a coalesced apparatus to better analyze what occurs in the coalescing section. A model to describe the hydrodynamic of the liquid mixture in the coalesced apparatus was applied to the system giving good agreement with the experimental data. |
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| Item Description: | "Major subject: Chemical Engineering". Vita. |
| Physical Description: | xiii, 178 leaves : illustrations ; 28 cm. Also available online. Issued also on microfiche from Lange Micrographics. |
| Bibliography: | Includes bibliographical references (leaves 98-100). |