Determination of Bodenstein number and axial dispersion of a triangular external loop airlift reactor

It was shown that the sampling loop, detector and connecting elements in the chromatographic set-up for determination of transport parameters by the dynamic method significantly influence the response peaks from columns packed with porous or nonporous particles. A method, based on the use of convolution theorem, was developed which can take these effects into account. The applicability of this method was demonstrated on the case of axial dispersion in a single-pellet-string column (SPSR) packed with nonporous particles. It is possible to handle also responses from columns packed with porous particles by a similar procedure.

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Computational fluid dynamics of rectangular external loop airlift reactor

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0009 ◽

2020 ◽

Vol 18 (5-6) ◽

Author(s):

Shivanand M. Teli ◽

Channamallikarjun S. Mathpati

Keyword(s):

Large Scale ◽

Lift Coefficient ◽

Volume Ratio ◽

Reynolds Stress Model ◽

Airlift Reactor ◽

Experimental Results ◽

Turbulent Dispersion ◽

Drag Forces ◽

External Loop ◽

Turbulent Models

AbstractThe novel design of a rectangular external loop airlift reactor is at present the most used large-scale reactor for microalgae culture. It has a unique future for a large surface to volume ratio for exposure of light radiation for photosynthesis reaction. The 3D simulations have been performed in rectangular EL-ALR. The Eulerian–Eulerian approach has been used with a dispersed gas phase for different turbulent models. The performance and applicability of different turbulent model’s i.e., K-epsilon standard, K-epsilon realizable, K-omega, and Reynolds stress model are used and compared with experimental results. All drag forces and non-drag forces (turbulent dispersion, virtual mass, and lift coefficient) are included in the model. The experimental values of overall gas hold-up and average liquid circulation velocity have been compared with simulation and literature results. It is seemed to give good agreements. For the different elevations in the downcomer section, liquid axial velocity, turbulent kinetic energy, and turbulent eddy dissipation experimental have been compared with different turbulent models. The K-epsilon Realizable model gives better prediction with experimental results.

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Hydrodynamic Considerations in an External Loop Airlift Reactor with a Modified Downcomer

Industrial & Engineering Chemistry Research ◽

10.1021/ie901311r ◽

2010 ◽

Vol 49 (4) ◽

pp. 1931-1936 ◽

Cited By ~ 5

Author(s):

Samuel T. Jones ◽

Theodore J. Heindel

Keyword(s):

Airlift Reactor ◽

External Loop

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Quenched Instationary Polymerization Systems, 6. The Direct Determination of Axial Dispersion in Size Exclusion Chromatography by Comparison of Theoretical and Ideal Peak Widths

Macromolecular Theory and Simulations ◽

10.1002/1521-3919(20020901)11:7<770::aid-mats770>3.0.co;2-1 ◽

2002 ◽

Vol 11 (7) ◽

pp. 770-776 ◽

Cited By ~ 7

Author(s):

Irene Schnöll-Bitai

Keyword(s):

Size Exclusion Chromatography ◽

Direct Determination ◽

Axial Dispersion ◽

Size Exclusion ◽

Exclusion Chromatography ◽

Peak Widths

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Numerical study of the hydrodynamics and mass transfer in the external loop airlift reactor

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq210522034k ◽

2021 ◽

pp. 34-34

Author(s):

Predrag Kojic ◽

Jovana Kojic ◽

Milada Pezo ◽

Jelena Krulj ◽

Lato Pezo ◽

...

Keyword(s):

Mass Transfer ◽

Transfer Coefficient ◽

Mass Transfer Coefficient ◽

Airlift Reactor ◽

Volumetric Mass Transfer Coefficient ◽

Cfd Model ◽

Gas Velocity ◽

Liquid Mass ◽

External Loop ◽

Liquid Mass Transfer

The objective of this study was to investigate the hydrodynamics and the gas-liquid mass transfer coefficient of an external-loop airlift reactor (ELAR). The ELAR was operated in three cases: different inlet velocities of fluids, different alcohols solutions (water, 0.5% methanol, 0.5% ethanol, 0.5% propanol and 0.5% butanol) and different concentration of methanol in solutions (0%, 0.5%, 1%, 2% and 5%). The influence of superficial gas velocity and various diluted alcohol solutions on hydrodynamics and gas-liquid mass transfer coefficient of the ELAR was studied. Experimentally, the gas hold-up, liquid velocities and volumetric mass transfer coefficient values in the riser and the downcomer were obtained from the literature source. A computational fluid dynamics (CFD) model was developed, based on two-phase flow, investigating different liquids regarding surface tension, assuming the ideal gas flow, applying the finite volume method and Eulerian-Eulerian model. The volumetric mass transfer coefficient was determined using CFD model, as well as artificial neural network model. The effects of liquid parameters and gas velocity on the characteristics of the gas-liquid mass transfer were simulated. These models were compared with appropriate experimental results. CFD model successfully succeed to simulate the influence of different alcohols regarding the number of C-atoms on hydrodynamics and mass transfer.

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