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Effective Analysis of Different Gas Diffusers on Bubble Hydrodynamics in Bubble Column and Airlift Reactors towards Mass Transfer Enhancement. Processes (Basel) 2021. [DOI: 10.3390/pr9101765] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Even bubble column reactors (BCR) and airlift reactors (ALR) have been developed in terms of various related aspects towards mass transfer enhancement, the effective analysis of gas diffuser types on mass transfer and gas–liquid hydrodynamic characteristics is still limited. Therefore, the present study aims to analyze the relative effect of different types of air diffusers on bubble hydrodynamics and mass transfer performance to understand their behaviors and define the best type. The experiments were conducted by varying different diffuser types, reactor types (BCR and ALR), and superficial gas velocity (Vg) (0.12 to 1.00 cm/s). Five air diffusers including commercial fine sand (F-sand) and coarse sand (C-sand) diffusers, and acrylic perforated diffusers with orifice sizes of 0.3 mm (H-0.3), 0.6 mm (H-0.6), and 1.2 mm (H-1.2), were used in this study. For every condition, it was analyzed in terms of bubble hydrodynamics and oxygen mass transfer coefficient (KLa). Lastly, the selected diffusers that provided the highest KLa coefficient were evaluated with a solid media addition case. The results of both reactor classes showed that F-sand, the smallest orifice diffuser, showed the smallest air bubbles (3.14–4.90 mm) compared to other diffusers, followed by C-sand, which larger about 22–28% on average than F-sand. ALR exhibited a better ability to maintain smaller bubbles than BCR. Moreover, F-sand and C-sand diffusers showed a slower rising velocity through their smaller bubbles and the tiny bubble recirculation in ALR. Using F-sand in ALR, the rising velocity is about 1.60–2.58 dm/s, which is slower than that in BCR about 39–54%. F-sand and C-sand were also found as the significant diffusers in terms of interfacial area and gas hold-up. Then, the KLa coefficient was estimated in every diffuser and reactor under the varying of Vg. Up to 270% higher KLa value was achieved from the use of F-sand and C-sand compared to other types due to their smaller bubbles generated/maintained and longer bubble retention time through slower rising velocity. After adding 10% ring shape plastic media into the reactors with F-sand and C-sand diffusers, a better performance was achieved in terms of KLa coefficient (up to 39%) as well as gas hold-up and liquid mixing. Lastly, ALR also had a larger portion of mixed flow pattern than BCR. This eventually promoted mass transfer by enhancing the mixed flow regime.
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Fathalla AS, Amin NK, El-Ashtoukhy ESZ, Sedahmed GH. Intensification of the Rate of Heat and Liquid‐Solid Mass Transfer at the Wall of a Bubble‐Column Reactor by Turbulence Promoters. Chem Eng Technol 2021. [DOI: 10.1002/ceat.202000616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Ahmed Salah Fathalla
- Alexandria University Faculty of Engineering, Chemical Engineering Department 21544 Alexandria Egypt
| | - Nevine Kamal Amin
- Alexandria University Faculty of Engineering, Chemical Engineering Department 21544 Alexandria Egypt
| | | | - Gomaa Hanafy Sedahmed
- Alexandria University Faculty of Engineering, Chemical Engineering Department 21544 Alexandria Egypt
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Dorostkar E, Khademi MH, Rahimi A. Modeling of Slurry Bubble‐Column Reactors with Emphasis on the Importance of Bubble Size Estimation. Chem Eng Technol 2021. [DOI: 10.1002/ceat.202000231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Elham Dorostkar
- University of Isfahan Department of Chemical Engineering College of Engineering Isfahan Iran
| | - Mohammad Hasan Khademi
- University of Isfahan Department of Chemical Engineering College of Engineering Isfahan Iran
| | - Amir Rahimi
- University of Isfahan Department of Chemical Engineering College of Engineering Isfahan Iran
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Wongwailikhit K, Warunyuwong P, Chawaloesphonsiya N, Dietrich N, Hébrard G, Painmanakul P. Gas Sparger Orifice Sizes and Solid Particle Characteristics in a Bubble Column - Relative Effect on Hydrodynamics and Mass Transfer. Chem Eng Technol 2017. [DOI: 10.1002/ceat.201700293] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Kritchart Wongwailikhit
- Chulalongkorn University; Department of Environmental Engineering; Faculty of Engineering; 254 Phayathai Road, 10330 Bangkok Thailand
- Université de Toulouse; INSA, UPS, INPT, LISBP; 135, Avenue de Rangueil 31077 Toulouse France
| | - Passaworn Warunyuwong
- Chulalongkorn University; Department of Environmental Engineering; Faculty of Engineering; 254 Phayathai Road, 10330 Bangkok Thailand
| | - Nattawin Chawaloesphonsiya
- Chulalongkorn University; Department of Environmental Engineering; Faculty of Engineering; 254 Phayathai Road, 10330 Bangkok Thailand
| | - Nicolas Dietrich
- Université de Toulouse; INSA, UPS, INPT, LISBP; 135, Avenue de Rangueil 31077 Toulouse France
| | - Gilles Hébrard
- Université de Toulouse; INSA, UPS, INPT, LISBP; 135, Avenue de Rangueil 31077 Toulouse France
| | - Pisut Painmanakul
- Chulalongkorn University; Department of Environmental Engineering; Faculty of Engineering; 254 Phayathai Road, 10330 Bangkok Thailand
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