Longitudinal Dispersion Coefficient of Liquid in Bubble Column

Kato, Yasuo; Nishiwaki, Akio

doi:10.1252/kakoronbunshu1953.35.912

Cited by 33 publications

(23 citation statements)

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“…In deriving the equations, the following assumptions were made, (a) Liquid-phase resistance controlled the rate of mass transfer, (b) Gas and liquid flowed under steady conditions, (c) From the carbon dioxide balance for a differential column volume at an arbitrary height, j^^=kLa(C-Hp) (8) Since the liquid phase is perfectly mixed, C is independent of z. Integration of Eq.…”

Section: Calculation Of Resultsmentioning

confidence: 99%

Mass transfer in a large bubble column.

Kataoka

Takeuchi

Nakao

et al. 1979

J. Chem. Eng. Japan

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Section: Calculation Of Resultsmentioning

confidence: 99%

Mass transfer in a large bubble column.

Kataoka

Takeuchi

Nakao

et al. 1979

J. Chem. Eng. Japan

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“…At relatively high values of U G (in the transition/heterogeneous flow regime), ε G decreases as U G increases. A scheme of correlation, similar to the one proposed by Mashelkar [192], was proposed by Kato and Nishiwaki [193], as reported by [24,193] and shown in Equation (6):…”

Section: Scheme Of Correlations By Lockett and Kirkpatrickmentioning

confidence: 99%

Two-Phase Bubble Columns: A Comprehensive Review

2018

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We present a comprehensive literature review on the two-phase bubble column; in this review we deeply analyze the flow regimes, the flow regime transitions, the local and global fluid dynamics parameters, and the mass transfer phenomena. First, we discuss the flow regimes, the flow regime transitions, the local and global fluid dynamics parameters, and the mass transfer. We also discuss how the operating parameters (i.e., pressure, temperature, and gas and liquid flow rates), the operating modes (i.e., the co-current, the counter-current and the batch modes), the liquid and gas phase properties, and the design parameters (i.e., gas sparger design, column diameter and aspect ratio) influence the flow regime transitions and the fluid dynamics parameters. Secondly, we present the experimental techniques for studying the global and local fluid dynamic properties. Finally, we present the modeling approaches to study the global and local bubble column fluid dynamics, and we outline the major issues to be solved in future studies.

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“…Early models treated the gas-phase as plug-flow, while the slurry-phase is often assumed to be perfectlymixed [341,342,347,352,356,372]. This latter assumption is inappropriate for simulating small-scale reactors, however, it could be viable for large-scale ones since the liquid-phase backmixing and the dispersion coefficients were reported to increase with reactor diameter [347].…”

Section: Reith Et Al []mentioning

confidence: 99%

Fischer–Tropsch Synthesis in Slurry Bubble Column Reactors: Experimental Investigations and Modeling – A Review

Basha

Sehabiague

Abdel‐Wahab

et al. 2015

International Journal of Chemical Reactor Engineering

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This paper presents an extensive review of the kinetics, hydrodynamics, mass transfer, heat transfer and mathematical as well as computational fluid dynamics (CFD) modeling of Low-Temperature Tropsch Synthesis (LTFT) synthesis in Slurry Bubble Column Reactors (SBCRs), with the aim of identifying potential research and development areas in this particular field. The kinetic expressions developed for F-T synthesis over iron and cobalt catalysts along with the water gas shift (WGS) reactions are summarized and compared. The experimental data and empirical correlations to predict the hydrodynamics (gas holdup, Sauter mean bubble diameter, and bubble rise velocity), mass transfer coefficients and heat transfer coefficients are presented. The effects of various operating variables, including pressure, temperature, gas velocity, catalyst concentration, reactor geometry, and reactor internals on the hydrodynamic and transport parameters as well as the performance of SBCRs are discussed. Additionally, modeling efforts of SBCRs, using axial dispersion models (ADM), multiple cell recirculation models (MCCM) and computational fluid dynamics (CFD), are addressed. This review revealed the following:(1) Numerous F-T and WGS kinetic rate expressions are available for cobalt and iron catalysts and one must be careful in selecting the appropriate expressions for LTFT. Iron catalyst suffers from severe attrition and subsequent deactivation in SBCRs and accordingly building a costly catalyst manufacturing facility onsite is required to maintain a steady operation of the F-T reactor;(2) Experimental data on the hydrodynamic and transport parameters at high pressures and temperatures, typical to those of actual F-T synthesis, remain scanty when compared with the plethora of studies conducted using air-water systems in small reactors at ambient conditions; (3) Several empirical correlations for predicting the hydrodynamic and mass as well heat transfer parameters are available and one should select those which consider the reactor diameter, gas mixtures and the potential foamability of the F-T liquids; (4) The effect of cooling internals configuration and sparger design on the hydrodynamic and transport parameters, local turbulence, mixing and catalyst attrition are yet to be seriously addressed; (5) The impact of operating variables on the hydrodynamic and transport parameters as well as the overall performance of the SBCRs should be investigated using actual F-T fluid-solid systems under typical pressures and temperatures using a large-scale reactor ( > 0.15 m ID) in the presence of gas spargers and cooling internals; (6) Significant efforts are still required in order to advance CFD modeling of SBCRs, particularly those pertaining to the relevant closure models, such as drag, lift and turbulence. Also, cooling internals configuration and the design as well as orientation of gas spargers should be accounted for in the CFD modeling; and (7) Proper validations of the CFD formulations using actual systems for F-T SBCR are needed.

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Longitudinal Dispersion Coefficient of Liquid in Bubble Column

Cited by 33 publications

References 0 publications

Mass transfer in a large bubble column.

Mass transfer in a large bubble column.

Two-Phase Bubble Columns: A Comprehensive Review

Fischer–Tropsch Synthesis in Slurry Bubble Column Reactors: Experimental Investigations and Modeling – A Review

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