Hydrodynamics of gas-lift reactors with a fast, liquid-phase reaction

Marco A. Márquez, Robert J. Amend, Ruben G. Carbonell, A. Eduardo Sáez, George W. Roberts

Research output: Contribution to journalConference article

16 Scopus citations

Abstract

The reactive absorption of CO2 into concentrated KOH solutions was studied in an external-loop, gas-lift reactor. Three different inlet gas compositions were used: air, 50-50 vol% air-CO2, and pure CO2. The downcomer liquid velocity and the axial profile of the cross-sectionally averaged gas holdup in the riser were measured. The reaction is so fast that the CO2 is consumed appreciably along the riser, and this causes a significant reduction in the liquid circulation relative to a system with no reaction. A one-dimensional, pseudo-steady-state model has been developed to describe the interactions of hydrodynamics, mass transfer, and chemical reaction for the bubbly flow regime in the riser. The model considers mass transfer from the gas to the liquid phase and its enhancement due to the chemical reaction, and is based on the spatially averaged equations of continuity, momentum, and macroscopic mechanical energy. The rate of liquid circulation, and the axial variation of gas holdup, gas composition, pressure, and gas and liquid velocity, are predicted. The gas/liquid mass transfer coefficient and the bubble radius at the sparger, neither of which was known a priori, were used to minimize the error of the data with respect to the model.

Original languageEnglish (US)
Pages (from-to)2263-2271
Number of pages9
JournalChemical Engineering Science
Volume54
Issue number13-14
DOIs
StatePublished - Jul 1 1999
EventProceedings of the 1998 15th International Symposium on Chemical Reaction Engineering, ISCRE 15 - Newport Beach, CA, USA
Duration: Sep 13 1998Sep 16 1998

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Keywords

  • Carbon dioxide
  • Gas-lift reactor
  • Hydrodynamics
  • Mass transfer
  • Modeling
  • Potassium hydroxide

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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