Journal ArticleDOI
Mass transfer in a rectangular air‐lift reactor: Effects of geometry and gas recirculation
Marc H. Siegel,Jose C. Merchuk +1 more
TLDR
It was found that the overall reactor mass transfer coefficient KLA could be correlated to the pneumatic power of gas input per total dispersion volume (P/VD) and to the true riser superficial gas velocity JGR for all experimental conditions examined.Abstract:
The interrelationships between the three parts of the air lift reactor, the riser, the downcomer, and gas-liquid separator, were examined with relation to the overall mass transfer in the reactor. This involved studying the mass transfer of oxygen from the gas phase to the liquid phase for 20 different reactor geometries. Both one- and two-sparger systems were studied. It was demonstrated that the gas-liquid separator plays a major role in reactor behavior and must be considered in reactor design. It was found that the overall reactor mass transfer coefficient KLA could be correlated to the pneumatic power of gas input per total dispersion volume (P/VD) and to the true riser superficial gas velocity JGR for all experimental conditions examined. The KLA is directly related to the P/VD with an exponent of approximately 1. "Two-sparger" systems, where an auxiliary gas sparger is placed near the downcomer entrance, have higher ab solute values for KLA than single-sparger systems.read more
Citations
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Journal ArticleDOI
Reactor Design Issues for Synthesis-Gas Fermentations.
TL;DR: This paper reviews recent progress in the development of synthesis‐gas fermentations, with emphasis on efforts to increase the efficiency of gas mass transfer.
Journal ArticleDOI
Mass-Transfer Properties of Microbubbles. 1. Experimental Studies
Marshall D. Bredwell,R M Worden +1 more
TL;DR: In this paper, the authors used a laser-diffraction technique to determine the interfacial area per unit gas volume, a.k.a. KL, for a synthesis-gas fermentation.
Journal ArticleDOI
Application of airlift gas-liquid-solid reactors in biotechnology
M.H. Siegel,Campbell W. Robinson +1 more
TL;DR: An overview of the current state of knowledge in air-laboratory design and operation can be found in this paper with a focus on external-loop air-flooding.
Journal ArticleDOI
Why use air-lift bioreactors?
TL;DR: Air-lift bioreactors are a relatively new type of fermenter, offering several advantages for large-scale bioprocesses, for animal and plant cell culture in particular, but some of the limitations are determined by the fluid dynamics and mass transfer characteristics of air-lift reactors.
Journal ArticleDOI
Oxygen mass transfer in a high solids loading three-phase internal-loop airlift reactor
TL;DR: In this article, the volumetric mass transfer coefficient was determined in a three-phase internal-loop air-lifting reactor with an enlarged degassing zone, and the effect of parameters such as the airflow rate (riser superficial gas velocities between 0.01 and 0.5 m/s), solids loading (up to 30%, v/v), solics density (1023 and 1048 kg/m 3 ) and the liquid-phase properties on kLa was studied.
References
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Book
Standard methods for the examination of water and wastewater
TL;DR: The most widely read reference in the water industry, Water Industry Reference as discussed by the authors, is a comprehensive reference tool for water analysis methods that covers all aspects of USEPA-approved water analysis.
Book
Wastewater Engineering Treatment Disposal Reuse
TL;DR: Wastewater Engineering: An Overview of Wastewater Engineering, Methods and Implementation Considerations as mentioned in this paper is a good starting point for a discussion of the issues of wastewater engineering. But, it is not a complete survey of the entire literature.
Journal ArticleDOI
Gas holdup and overall volumetric oxygen transfer coefficient in airlift contactors
TL;DR: The two major types of airlift contactors, concentric‐tube and external‐loop, were investigated for their gas holdup (riser and downcomer) and overall mass transfer characteristics.
Journal ArticleDOI
Air-lift reactor analysis: Interrelationships between riser, downcomer, and gas-liquid separator behavior, including gas recirculation effects
TL;DR: In this paper, an approach to air-lift reactor analysis is presented that examines the riser, downcomer, and gas-liquid separator as three interconnected and interrelated elements.
Journal ArticleDOI
Local hold-up and liquid velocity in air-lift reactors
Jose C. Merchuk,Yehuda Stein +1 more
TL;DR: In this article, the authors measured local hold-up and liquid recirculation rate in an air-lift reactor with two types of gas spargers using a manometric technique.