Pereira_et_al_as_accepted.pdf (1.1 MB)
CO2 dissolution and design aspects of a multiorifice oscillatory baffled column
journal contribution
posted on 2015-08-03, 08:57 authored by Filipa M. Pereira, Diana Z. Sousa, M. Madelena Alves, Malcolm R. Mackley, Nuno ReisDissolution of CO2 in water was studied for a batch vertical multiorifice baffled column (MOBC) with varying orifice diameters (d0) of 6.4-30 mm and baffle open area (α) of 15-42%. Bubble size distributions (BSDs) and the overall volumetric CO2 mass transfer coefficient (KLa) were experimentally evaluated for very low superficial gas velocities, UG of 0.12-0.81 mm s-1, using 5% v/v CO2 in the inlet gas stream at a range of fluid oscillations (f = 0-10 Hz and x0 = 0-10 mm). Remarkably, baffles presenting large do = 30 mm and α = 36%, therefore in the range typically found for single-orifice oscillatory baffled columns, were outperformed with respect to BSD control and CO2 dissolution by the other baffle designs or the same aerated column operating without baffles or fluid oscillations. Flow visualization and bubble tracking experiments also presented in this study established that a small do of 10.5 mm combined with a small value of α = 15% generates sufficient, strong eddy mixing capable of generating and trapping an extremely large fraction of microbubbles in the MOBC. This resulted in increased interfacial area yielding KLa values up to 65 ± 12 h-1 in the range of the UG tested, representing up to 3-fold increase in the rate of CO2 dissolution when compared to the unbaffled, steady column. In addition, a modi fied oscillatory Reynolds number, Re′o and Strouhal number, St' were presented to assist on the design and scale-up of gas-liquid systems based on multiorifice oscillatory ba ffled columns. This work is relevant to gas-liquid or multiphase chemical and biological systems relying on efficient dissolution of gaseous compounds into a liquid medium.
Funding
The authors acknowledge financial support of Fundação para a Ciência e Tecnologia (FCT) and the European Social Fund (ESF) through Ph.D. Grant SFRH/BD/62273/2009 awarded to F. M. Pereira. N. M. Reis is also grateful to the European Commission through the Marie Curie programme and to BBSRC, UK, for financial support.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Chemical Engineering
Published in
Industrial and Engineering Chemistry ResearchVolume
53Issue
44Pages
17303 - 17316Citation
PEREIRA, F.M. ... et al, 2014. CO2 dissolution and design aspects of a multiorifice oscillatory baffled column. Industrial and Engineering Chemistry Research, 53(44), pp.17303-17316.Publisher
© American Chemical SocietyVersion
- AM (Accepted Manuscript)
Publisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2014Notes
This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in Industrial and Engineering Chemistry Research, copyright © American Chemical Society after peer review. To access the final edited and published work, see http://pubs.acs.org/doi/abs/10.1021/ie403348g.ISSN
0888-5885eISSN
1520-5045Publisher version
Language
- en