The mixer-settler principle as a separation unit in supercritical fluid processes

Citation
A. Pietsch et R. Eggers, The mixer-settler principle as a separation unit in supercritical fluid processes, J SUPERCR F, 14(2), 1999, pp. 163-171
Citations number
15
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physical Chemistry/Chemical Physics","Chemical Engineering
Journal title
JOURNAL OF SUPERCRITICAL FLUIDS
ISSN journal
0896-8446 → ACNP
Volume
14
Issue
2
Year of publication
1999
Pages
163 - 171
Database
ISI
SICI code
0896-8446(19990101)14:2<163:TMPAAS>2.0.ZU;2-U
Abstract
Processes with supercritical fluids are known for both solid and liquid mat erials. Liquids are typically brought into contact with the supercritical f luid in countercurrent columns. In recent years, high-pressure spraying pro cesses such as the spray extraction of viscous media have been investigated . The central idea is to improve mass transfer by dispersing the liquid pha se in the supercritical phase. A mixer-settler system is investigated for t he regeneration of caffeine-loaded CO2 at various conditions. Water is spra yed into the CO2 flow and the resulting two-phase flow passes through a sta tic mixer to intensify phase contact and prevent coalescence of the water p hase. The system shows an efficiency of 80-90% in comparison with the theor etical maximum based on ternary equilibrium data from the literature. The p ressure loss of the static mixer (Kenics) is determined experimentally for various conditions. The pressure drop of the two-phase Bow depends on CO2 v elocity and is significantly determined by the mass ratio. It does not exce ed 2500 Pa in the present investigations, and can be neglected in supercrit ical fluid plant design. (C) 1999 Elsevier Science B.V. All rights reserved .