D107 Study on a Single Bubble Absorption of Ammonia/Water System : Influence of Pressure on Bubble Diameter and Mass Transfer Coefficient

2001 ◽  
Vol 2001 (0) ◽  
pp. 153-154
Author(s):  
Jun YAMADA ◽  
Yoshinori HAMAMOTO ◽  
Shyouji YOSHIDA ◽  
Atsushi AKISAWA ◽  
Takao KASHIWAGI
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Bubble Diameter ◽  
Water System ◽  
Single Bubble ◽  
Ammonia Water

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.

Enhancement of Gas Physical Absorption in Gas-Liquid-Liquid System

2011 ◽  
Vol 201-203 ◽  
pp. 2870-2874
Author(s):  
Wen Xiu Li ◽  
Guang Rong Xu ◽  
Zhi Gang Zhang ◽  
Zhi Ling Ji
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Organic Phase ◽  
Amplification Factor ◽  
Bubble Diameter ◽  
Interfacial Area ◽  
Volumetric Mass Transfer Coefficient ◽  
Absorption Increase ◽  
Physical Absorption

The enhancement of physical absorption of CO2 in the presence of second liquid phase (dispersed organic phase) was investigated due to many important industrial applications. Gas-liquid interfacial area, volumetric mass transfer coefficient and amplification factor were calculated and discussed using penetration model. The experimental results indicated that addition of the dispersed organic phase to water leads to the increase of volumetric mass transfer coefficient by 46%, 34%, 20% for heptanol, toluene and heptane respectively. The performed in this paper shows that addition of the dispersed organic phase to water increases gas-liquid interfacial area and reduces bubble diameter. These two effects play an essential role in the rate of carbon dioxide absorption increase. The effect of enhancement could be quantified by an amplification factor.

scholarly journals Experimental Study and Numerical Simulation of Gas–Liquid Two-Phase Flow in Aeration Tank Based on CFD-PBM Coupled Model

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1569 ◽  
Author(s):  
Liang Dong ◽  
Jinnan Guo ◽  
Jiawei Liu ◽  
Houlin Liu ◽  
Cui Dai
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Two Phase Flow ◽  
Bubble Diameter ◽  
Coupled Model ◽  
Balance Model ◽  
Aeration Tank ◽  
Phase Flow ◽  
Two Phase

Gas–liquid two-phase flow directly determines the efficiency and stability of the aeration tank. In this paper, a gas–liquid two-phase testbed is built to explore the aeration performance and internal flow in an aeration tank, including an inverted-umbrella impeller (immersion depth of 0 mm, rotational speed of 250 r/min). Also, the running process is simulated by computational fluid dynamics (CFD) with a population balance model (PBM), and mass transfer coefficient is compared to the experiment. The experimental results show that there is a big difference in bubble diameter, ranging from 0.4 to 1.6 mm. The simulation shows that the impeller intensely draws air above the free surface into the shallow liquid, and the circulation vortex entrains it to the bottom areas faster. Compared with the experiment, the simulated interfacial area and standard oxygen mass transfer coefficient is 12% more and 3% less, respectively. The results reveal that CFD-PBM coupled model can improve the accuracy of calculation, resulting in the simulation of gas–liquid two-phase flow.

scholarly journals Ultrasonic Investigation of Hydrodynamics and Mass Transfer in a Gas-Liquid(-Liquid) Stirred Vessel

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
A.H.G. Cents ◽  
D.W.F. Brilman ◽  
G.F. Versteeg
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Water System ◽  
Interfacial Area ◽  
Volumetric Mass Transfer Coefficient ◽  
Volume Fractions ◽  
Liquid Mass ◽  
Liquid Mass Transfer ◽  
Transfer Parameters

The rate of gas-liquid mass transfer is very important in several industrial chemical engineering applications. In many multi-phase reaction systems, however, the mechanism of mass transfer is not well understood. This is for instance the case in Gas-Liquid-Solid (G-L-S) and Gas-Liquid-Liquid (G-L-L) systems. To obtain more knowledge of the mechanism of mass transfer, the mass transfer coefficient, kL, and the interfacial area, a, should be studied separately. In this work an ultrasonic measurement technique is used to study the local interfacial area in a standard sized vessel, equipped with a Rushton type impeller. This is done in combination with experimental determination of the volumetric mass transfer coefficient, kLa, using the dynamic oxygen method, to obtain values for kL. The gas hold-up is determined additionally to obtain values for the Sauter mean bubble diameter at different positions in the vessel. In a coalescing air-water system the bubble size was non-uniform throughout the vessel and increased from small bubbles at the impeller along with the flow pattern to larger sizes in the bulk of the vessel. In a non-coalescing electrolyte system the vessel was much more uniform and the bubbles were smaller when compared to the air-water system. To obtain overall values of the mass transfer parameters the local values were integrated according to their volume fraction in the reactor. In both coalescing and non-coalescing systems the overall values for the mass transfer parameters were in good agreement with literature correlations. The addition of small volume-fractions of toluene to an air-water system caused a strong decrease in both the volumetric mass transfer coefficient and in the gas hold-up. The interfacial area increased, however, but it was shown that this was due to the presence of microbubbles in the solution, which do not take part in the mass transfer process. The enhancing effect on gas-liquid mass transfer due to the addition of larger volume-fractions of toluene could be described reasonably well by a homogeneous model of the shuttle mechanism.

scholarly journals Mass transfer investigation in a horizontal–vertical pulsed packed extraction column

RSC Advances ◽  
2017 ◽  
Vol 7 (87) ◽  
pp. 55326-55335 ◽  
Author(s):  
Sajad Khooshechin ◽  
Mohammad Ali Moosavian ◽  
Jaber Safdari ◽  
Mohammad Hassan Mallah
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Pilot Plant ◽  
Water System ◽  
Extraction Column ◽  
Hydrodynamic Parameters ◽  
System P ◽  
Acetone Water

In this study, hydrodynamic parameters and the mass transfer coefficient were investigated in a pilot plant of a horizontal–vertical pulsed packed extraction column using a toluene–acetone–water system.

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