Mass transfer in an external-loop airlift reactor: experiments and modeling

1997 ◽  
Vol 52 (21-22) ◽  
pp. 3909-3917 ◽  
Author(s):  
H. Dhaouadi ◽  
S. Poncin ◽  
J.M. Hornut ◽  
G. Wild ◽  
P. Oinas ◽  
...  
Author(s):  
Predrag Kojic ◽  
Jovana Kojic ◽  
Milada Pezo ◽  
Jelena Krulj ◽  
Lato Pezo ◽  
...  

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.


2014 ◽  
Vol 22 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Mona Ebrahimi Fakhari ◽  
Mostafa Keshavarz Moraveji ◽  
Reza Davarnejad

2007 ◽  
Vol 133 (1-3) ◽  
pp. 257-264 ◽  
Author(s):  
Kaustubha Mohanty ◽  
Debabrata Das ◽  
Manindra Nath Biswas

2012 ◽  
Vol 512-515 ◽  
pp. 2405-2411
Author(s):  
Qian Wu ◽  
Ma Lin Liu ◽  
Tong Wang Zhang

A mathematical model considering the inter-phase mass transfer both in the down-comer and the riser of an external-loop airlift reactor was established in this paper. The calculated global volumetric mass transfer coefficient based on the assumption of continuous stirred tank reactor (CSTR) was different from the local volumetric mass transfer coefficients by the newly proposed mathematical model and the difference was discussed. The effects of mass transfer in the down-comer, the hydrodynamic pressure and the experimental time on the mass transfer coefficient measurement model have been studied in detail. And it was also proved that only the global volumetric mass transfer coefficient, but not the local volumetric mass coefficient, can be obtained from a time-concentration curve in the external-loop airlift reactor.


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