Gas-liquid reaction and mass transfer in microstructured coiled flow inverter. (21st September 2017)

• Record Type: Journal Article
• Authors: Kurt, Safa Kutup; Warnebold, Fabian; Nigam, Krishna D.P.; Kockmann, Norbert
• Is Part Of: Chemical engineering science. Volume 169(2017)
• Page Start: 164
• Page End: 178
• Publication Date: 2017-09-21
• Subjects: Coiled flow inverter -- Microreactor -- Slug flow -- Gas-liquid reaction -- Dean vortices -- Continuous process; Chemical engineering -- Periodicals; Génie chimique -- Périodiques; Chemical engineering; Periodicals; Electronic journals; 660
• DOI: 10.1016/j.ces.2017.01.017
• Languages: English
• ISSNs: 0009-2509

Abstract

Highlights: Gas-liquid slug flow map was generated in a large operation window for coiled tubes. Secondary flow patterns increases gas-liquid flow friction factor in coiled tubes. Dean vortices and their inversions with 90° bends enhance G-L mixing in MCFI. MCFI provides up to 14% higher conversion in comparison to SCR and MHCT. MCFI offers enhanced G-L mass transfer performance with longer residence times. Abstract: Microstructured coiled flow inverter (MCFI) as a helically coiled tubular device with 90° alternating bends provides enhanced radial mixing due to secondary flow (Dean vortices) in different planes. Liquid-liquid mass transfer characterization in MCFI revealed higher mass transfer rates compared to other capillary setups. However, the influence of Dean vortices and 90° bends on gas-liquid mass transfer has not been investigated and described yet. Different reactor setups, i.e. MCFI, straight capillary, helical coil, and bend reactor were fabricated from FEP tubes (ID = 1 mm). Gas-liquid mass transfer performance was investigated for a gas-liquid reaction system, i.e. cobalt (II) catalyzed air oxidation of sodium sulfite. Two-phase slug flow hydrodynamics and pressure drop were experimentally characterized, while the influence of operating and geometrical reactor parameters on conversion was investigated for reactor setups. MCFI offers up to 14% higher conversion in comparison to other capillary setups. Mixing within the liquid phase is enhanced by the formation of Dean vortices and additional direction change via 90° bends, which contribute to the internal diffusion in the liquid phase.