Development of Unified Correlations for Volumetric Mass-Transfer Coefficient and Effective Interfacial Area in Bubble Column Reactors for Various Gas−Liquid Systems Using Support Vector Regression

2009 ◽  
Vol 48 (9) ◽  
pp. 4216-4236 ◽  
Author(s):  
Ankit B. Gandhi ◽  
Prashant P. Gupta ◽  
Jyeshtharaj B. Joshi ◽  
Valadi K. Jayaraman ◽  
Bhaskar D. Kulkarni
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Support Vector Regression ◽  
Bubble Column ◽  
Interfacial Area ◽  
Support Vector ◽  
Volumetric Mass Transfer Coefficient ◽  
Bubble Column Reactors ◽  
Liquid Systems

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 Gas Hold-Up and Mass Transfer in a Vessel with an Unsteady Rotating Concave Blade Impeller

Energies ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 346
Author(s):  
Sebastian Frankiewicz ◽  
Szymon Woziwodzki
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Interfacial Area ◽  
Transfer Efficiency ◽  
Volumetric Mass Transfer Coefficient ◽  
Mass Transfer Efficiency ◽  
Liquid Systems ◽  
The Creation

The steady mixing of gas-liquid systems is used where a large development of the interfacial area is required. However, the presence of gas in the liquid reduces the efficiency of mass transfer by reducing the mixing power, due to the creation of gas formations behind the impeller blades and the reduction in density. The efficiency of mass transfer can be increased by using a concave blade impeller or unsteady mixing. Mass transfer efficiency studies for these impellers and unsteady mixing are limited. This paper presents an analysis of the influence of the impeller construction on the gas hold-up and volumetric mass transfer coefficient kLa. Impellers with a different number of concave blades, and with alternatively arranged concave blades, were analyzed. The obtained results were compared with the standard flat blade turbine. The obtained results indicate that the arrangement of the concave blades has the greatest effect on reducing the gas hold-up and kLa. Higher values were obtained for the four-bladed and six-bladed impellers. A comparison of the gas hold-up rate for the unsteady and steady mixing has shown that for steady mixing greater gas hold-up is achieved. The volumetric mass transfer coefficient for unsteady mixing is also greater compared to steady mixing, indicating greater efficiency in mass transfer.

scholarly journals Determination of the ozone volumetric mass transfer coefficient in bubble column with two-fluid nozzle gas distributor

2015 ◽  
Vol 69 (5) ◽  
pp. 553-559 ◽  
Author(s):  
Milica Djekovic-Sevic ◽  
Nevenka Boskovic-Vragolovic ◽  
Ljiljana Takic ◽  
Radmila Garic-Grulovic ◽  
Srdjan Pejanovic
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Bubble Column ◽  
Operating Conditions ◽  
Volumetric Mass Transfer Coefficient ◽  
Gas Distributor ◽  
Liquid Mass Transfer ◽  
Two Fluid

Experimental investigation of gas-liquid mass transfer of ozone in water, in bubble column with two-fluid nozzle gas distributor (BKDM), under different operating conditions, are presented in this work. The main objective was to determine the ozone volumetric mass transfer coefficient, kL a, in calm uniform section of the column, under different values of gas and liquid flow rates. Obtained values of these coefficients were compared with the values in countercurrent bubble column. The critical liquid flowrate, when gas hold up reaches its maximum, was experimentally determined. It was shown that the maximum value of the ozone volumetric mass transfer coefficient is obtained just when liquid flowrate is at its critical value.

scholarly journals Study on Mass Transfer Characteristics of Hydrate-based Gas Absorber

2021 ◽  
Vol 333 ◽  
pp. 04002
Author(s):  
Shun Takano ◽  
Ryosuke Ezure ◽  
Yusuke Takahashi ◽  
Hiroyuki Komatsu ◽  
Kazuaki Yamagiwa ◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Gas Separation ◽  
Bubble Column ◽  
Hydrate Formation ◽  
Continuous Operation ◽  
Gas Absorption ◽  
Volumetric Mass Transfer Coefficient ◽  
Type Apparatus

Hydrated-based gas separation is a method capable of selectively separating and recovering greenhouse gases. Although a conventional hydrate-based gas separation apparatus is a batch or a semi-batch system, continuous operation is preferable to increase the throughput of gas without changing the apparatus volume. Recently, we proposed a flow type apparatus to allow continuous operation of hydrate formation (absorption) and subsequent decomposition (desorption). The aim of this study is to investigate the mass transfer characteristics of the continuous apparatus using the HFC134a-N2 mixed gas system. The volumetric mass transfer coefficient was calculated especially during a steady state of gas absorption. Besides, we compared mass transfer performance between the hydrate-based gas absorber and a conventional bubble column. Sodium dodecyl sulfate was used as a hydrate dispersant. In the flow type apparatus, the gas-liquid contact was good and the hydrate slurry state was observed during hydrate formation. In the surfactant solution, the volumetric mass transfer coefficient increased in comparison with that in water. The volumetric mass transfer coefficient with hydrate was higher than that of the bubble column. These results suggest that hydrate formation improves gas absorption performance.

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