Interfacial area, bubble coalescence and mass transfer in bubble column reactors

AIChE Journal ◽  
1983 ◽  
Vol 29 (2) ◽  
pp. 312-319 ◽  
Author(s):  
D. N. Miller
Keyword(s):  
Mass Transfer ◽  
Bubble Column ◽  
Interfacial Area ◽  
Bubble Coalescence ◽  
Bubble Column Reactors

Effect of scale-up on rate of interfacial mass transfer in shallow-bed bubble column reactors

1983 ◽  
Vol 48 (3) ◽  
pp. 703-710
Author(s):  
Milan Rylek ◽  
Karel Svoboda ◽  
Jindřich Zahradník
Keyword(s):  
Mass Transfer ◽  
Cross Section ◽  
Bubble Column ◽  
Scale Up ◽  
Interfacial Area ◽  
Bubble Columns ◽  
Transfer Coefficients ◽  
Bubble Column Reactors ◽  
Specific Interfacial Area ◽  
Interfacial Mass Transfer

Absorption rates of CO2 into aqueous solutions of sodium hydroxide were measured in shallow-bed bubble columns with sieve trays as gas distributors. Experiments were carried out in two cylindrical columns (ID 0.15 and 0.30 m) and in a rectangular unit with square cross-section 1 m2. Liquid side mass transfer coefficients (kL) and specific interfacial area (a) were evaluated from experimental data of absorption rates. The effect of bubble-bed dimensions on mass transfer characteristics is discussed and recommendations for scale-up of bubble column reactors are presented.

The effect of liquid phase properties on gas holdup in bubble column reactors

1987 ◽  
Vol 52 (2) ◽  
pp. 335-347 ◽  
Author(s):  
Jindřich Zahradník ◽  
Rudolf Peter ◽  
František Kaštánek
Keyword(s):  
Liquid Phase ◽  
Aqueous Solutions ◽  
Bubble Column ◽  
Gas Holdup ◽  
Bubble Coalescence ◽  
Large Set ◽  
Bubble Column Reactors ◽  
Liquid Systems ◽  
Coalescence Suppression ◽  
Phase Properties

The effect of liquid phase properties on gas holdup in bubble column reactors was investigated within a large set of gas-liquid systems. Air was used as a gaseous phase in all experiments, liquid phases included distilled water and aqueous solutions of alcohols and electrolytes. Gas holdup values were determined in a sieve tray bubble column 0.15 m i.d. under conditions of stable uniform gas distribution and an attempt was made to relate these data with values of bubble coalescence ratio determined for respective gas-liquid systems in a coalescence cell. Experimental results proved strong influence of solute addition on bubble coalescence reduction and on the increase of gas holdup values in aqueous solutions of both alcohols and electrolytes. An unambiguous dependence was observed between gas holdup data and values of bubble coalescence ratio in alcohols solutions, the effect of coalescence suppression on gas holdup enhancement increased markedly with increasing gas flow rates. An empirical equation was proposed for estimation of lower and upper gas holdup limits in electrolyte solutions within the coalescence suppression region, i.e. at solute concentrations above coalescence transition value.With the exception of concentrated glycerol solutions, homogeneous bubble beds were generated in all gas-liquid systems using the appropriate gas distributing plate. The positive effect of coalescence restraining on gas holdup values was even more significant in homogeneous bubble beds than under conditions of turbulent bubbling regime.

Influence of Particles and Electrolyte on Gas Hold-Up and Mass Transfer in a Slurry Bubble Column

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Keshav C Ruthiya ◽  
John van der Schaaf ◽  
Ben F.M. Kuster ◽  
Jaap C Schouten
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Bubble Column ◽  
Bubble Diameter ◽  
Interfacial Area ◽  
Large Bubble ◽  
Volumetric Mass Transfer Coefficient ◽  
Gas Velocity ◽  
Slurry Concentration

In this paper, the influence of carbon and silica particle slurry concentration up to 20 g/l (4 vol%) on regime transition, gas hold-up, and volumetric mass transfer coefficient is studied in a 2-dimensional slurry bubble column. From high speed video image analysis, the average large bubble diameter, the frequency of occurrence of large bubbles, the gas-liquid interfacial area, and the large bubble hold-up are obtained. The liquid side mass transfer coefficient is calculated from the volumetric mass transfer coefficient and the gas-liquid interfacial area. The lyophilic silica particles are rendered lyophobic by a methylation process to study the influence of particle wettability. The influence of organic electrolyte (sodium gluconate) and the combination of electrolyte and particles is also studied. It is found that lyophilic silica, lyophobic silica, and lyophobic carbon particles at concentrations larger than 2 g/l (0.4 vol%) decrease the gas hold-up and shift the regime transition point (where the first large bubbles appear) to a lower gas velocity. The volumetric mass transfer coefficient increases with gas velocity, increases with electrolyte concentration, decreases with slurry concentration, and is higher for lyophobic particles. The liquid side mass transfer coefficient increases with gas velocity, bubble diameter, and is higher for lyophobic particles. A correlation for the mass transfer coefficient based on dimensionless numbers is proposed for the heterogeneous regime.

scholarly journals Effect of Different Configurations on Bubble Cutting and Process Intensification in a Micro-Structured Jet Bubble Column Using Digital Image Analysis

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2220
Author(s):  
Guanghui Chen ◽  
Zhongcheng Zhang ◽  
Fei Gao ◽  
Jianlong Li ◽  
Jipeng Dong
Keyword(s):  
Mass Transfer ◽  
Image Analysis ◽  
Flow Field ◽  
Digital Image ◽  
Bubble Size ◽  
Digital Image Analysis ◽  
Liquid Velocity ◽  
Bubble Column ◽  
Process Intensification ◽  
Interfacial Area

An experimental study was conducted in this work to investigate the effect of different configurations on bubble cutting and process intensification in a micro-structured jet bubble column (MSJBC). Hydrodynamic parameters, including bubble size, flow field, liquid velocity, gas holdup as well as the interfacial area, were compared and researched for a MSJBC with and without mesh. The bubble dynamics and cutting images were recorded by a non-invasive optical measurement. An advanced particle image velocimetry technique (digital image analysis) was used to investigate the influence of different configurations on the surrounding flow field and liquid velocity. When there was a single mesh and two stages of mesh compared with no mesh, the experimental results showed that the bubble size decreased by 22.7% and 29.7%, the gas holdup increased by 5.7% and 9.7%, and the interfacial area increased by more than 34.8% and 43.5%, respectively. Significant changes in the flow field distribution caused by the intrusive effect of the mesh were observed, resulting in separate liquid circulation patterns near the wire mesh, which could alleviate the liquid back-mixing. The mass transfer experiment results on the chemical absorption of CO2 into NaOH enhanced by a mass transfer process show that the reaction time to equilibrium is greatly reduced in the presence of the mesh in the column.

Effect of surfactants on mass transfer coefficients in bubble column contactors: an interpretative critical review study

2019 ◽  
Vol 0 (0) ◽  
Author(s):  
Sahand Nekoeian ◽  
Masoud Aghajani ◽  
Seyed Mehdi Alavi ◽  
Fatemeh Sotoudeh
Keyword(s):  
Mass Transfer ◽  
Bubble Column ◽  
Interfacial Area ◽  
Positive Influence ◽  
Transfer Coefficients ◽  
Mass Transfer Coefficients ◽  
Future Studies ◽  
Specific Interfacial Area ◽  
Transfer Operation ◽  
Review Study

Abstract Since surfactants have been recognized as the most frequently faced contaminants of bubble column-related processes over time, their impact on the mass transfer operation of these columns has become a demanding research interest for two recent decades. Despite the similarities expressing the overall negative and positive influence of these chemicals on mass transfer coefficients and specific interfacial area, respectively, the discrepancies and, sometimes, paradoxical results are still under debate in the literature. To make a more comprehensive recognition of the mentioned subject, the current paper has tried to pave the path by reviewing all the major methods utilized in related research works. Thereafter, an interpretative argumentative comparison of the main findings of relevant studies has also been proposed, enlightening some of the research gaps which can be the potential candidates for future studies.

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