Gas—Liquid Mass Transfer Coefficient in Stirred Tank Reactors

Yawalkar, Archis A.; Heesink, Albertus B.M.; Versteeg, Geert; Pangarkar, Vishwas G.

doi:10.1002/cjce.5450800507

Cited by 62 publications

(42 citation statements)

References 18 publications

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“…This power reduction is due to the formation of cavities behind the impeller blades and the different density of the fluid under gassed and ungassed conditions (van't Riet and Smith, 1973). The effect of aeration has been extensively studied by Nienow et al (1977), Oosterhuis and Kossen (1981), Warmoeskerken and Smith (1981) and Yawalkar et al (2002) for a single impeller system as studied here. It has been shown that the gassed power input is usually 30-40% of the ungassed power input depending on the type of impeller and aeration rates used (Oosterhuis and Kossen, 1985).…”

Section: Resultsmentioning

confidence: 94%

“…In Figure 4 N CD is represented by the minimum P g /P ug values in each data set. The flow pattern at this operating condition is characterized by a fully dispersed bubbled regime throughout the fluid without any flooding of the impeller (Yawalkar et al, 2002). At this point however the gas hold up is not sufficient to promote gross recirculation of bubbles throughout the dispersion.…”

Section: Resultsmentioning

confidence: 96%

“…The correlation presented by Hughmark (1980) for a six-bladed disc turbine has been applied over a wide range of system configurations and operating parameters. The correlation was based on 391 data sets with a standard deviation of 0.1117 and is considered to be very reliable (Hughmark, 1980;van't Riet and Tramper, 1991;Yawalkar et al, 2002). Although Koloini et al (1989) reported that Hughmark's correlation predicted higher values for power input compared to their experimental data, in the case of the miniature bioreactor this correlation also slightly under estimates the power input compared to the measured values, especially at higher stirrer speeds.…”

Section: Correlation Of Miniature Bioreactor Energy Dissipation Ratesmentioning

confidence: 95%

“…Consequently, the most utilized criteria for scale translation are based on empirical relationships which correlate P g /V and k L a (Vilaca et al, 2000). This criteria account for the relevant parameters influencing gas-liquid mass transport, such as agitation (via power input) and aeration (superficial gas velocity) (Yawalkar et al, 2002). …”

Section: Introductionmentioning

confidence: 99%

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Quantification of power consumption and oxygen transfer characteristics of a stirred miniature bioreactor for predictive fermentation scale‐up

Gill

Appleton²,

Baganz

et al. 2008

Biotech & Bioengineering

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Miniature parallel bioreactors are becoming increasingly important as tools to facilitate rapid bioprocess design. Once the most promising strain and culture conditions have been identified a suitable scale-up basis needs to be established in order that the cell growth rates and product yields achieved in small scale optimization studies are maintained at larger scales. Recently we have reported on the design of a miniature stirred bioreactor system capable of parallel operation [Gill et al. (2008); Biochem Eng J 39:164-176]. In order to enable the predictive scale-up of miniature bioreactor results the current study describes a more detailed investigation of the bioreactor mixing and oxygen mass transfer characteristics and the creation of predictive engineering correlations useful for scale-up studies. A Power number of 3.5 for the miniature turbine impeller was first established based on experimental ungassed power consumption measurements. The variation of the measured gassed to ungassed power ratio, P(g)/P(ug), was then shown to be adequately predicted by existing correlations proposed by Cui et al. [Cui et al. (1996); Chem Eng Sci 51:2631-2636] and Mockel et al. [Mockel et al. (1990); Acta Biotechnol 10:215-224]. A correlation relating the measured oxygen mass transfer coefficient, k(L)a, to the gassed power per unit volume and superficial gas velocity was also established for the miniature bioreactor. Based on these correlations a series of scale-up studies at matched k(L)a (0.06-0.11 s(-1)) and P(g)/V (657-2,960 W m(-3)) were performed for the batch growth of Escherichia coli TOP10 pQR239 using glycerol as a carbon source. Constant k(L)a was shown to be the most reliable basis for predictive scale-up of miniature bioreactor results to conventional laboratory scale. This gave good agreement in both cell growth and oxygen utilization kinetics over the range of k(L)a values investigated. The work described here thus gives further insight into the performance of the miniature bioreactor design and will aid its use as a tool for rapid fermentation process development.

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Section: Resultsmentioning

confidence: 94%

Section: Resultsmentioning

confidence: 96%

Section: Correlation Of Miniature Bioreactor Energy Dissipation Ratesmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Quantification of power consumption and oxygen transfer characteristics of a stirred miniature bioreactor for predictive fermentation scale‐up

Gill

Appleton²,

Baganz

et al. 2008

Biotech & Bioengineering

View full text Add to dashboard Cite

show abstract

“…The power consumption in ungassed systems is always higher than the power consumption in gassed systems, since aeration significantly influences the power drawn from the impeller by the fluid. 7 The effect of aeration has been studied extensively by Nienow et al, 91 Oosterhuis and Kossen, 92 Yawalkar et al 93 and Gogate et al 46 It has been shown that the gassed power input is usually 30-40% of the ungassed power input, …”

Section: Scale-up Based On Volumetric Power Consumptionmentioning

confidence: 99%

Bioprocess scale‐up: quest for the parameters to be used as criterion to move from microreactors to lab‐scale

Marques

Cabral

Fernandes

2010

J of Chemical Tech & Biotech

101

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Advances in high-throughput process development and optimization involve the rational use of miniaturized stirred bioreactors, instrumented shaken flasks and microtiter plates. As expected, each one provides different levels of control and monitoring, requiring a compromise between data quantity and quality. Despite recent advances, traditional shaken flasks with nominal volumes below 250 mL and microtiter plates are still widely used to assemble wide arrays of biotransformation/bioconversion data, because of their simplicity and low cost. These tools are key assets for faster process development and optimization, provided data are representative. Nonetheless, the design, development and implementation of bioprocesses can present variations depending on intrinsic characteristics of the overall process. For each particular process, an adequate and comprehensive approach has to be established, which includes pinpointing key issues required to ensure proper scaleup. Recently, focus has been given to engineering characterization of systems in terms of mass transfer and hydrodynamics (through gaining insight into parameters such as k L a and P/V at shaken and microreactor scale), due to the widespread use of small-scale reactors in the early developmental stages of bioconversion/biotransfomation processes. Within this review, engineering parameters used as criteria for scaling-up fermentation/bioconversion processes are discussed. Particular focus is on the feasibility of the application of such parameters to small-scale devices and concomitant use for scale-up.

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Two‐ and Three‐Phase Chemical Reactors

Pangarkar¹

2018

Kirk-Othmer Encyclopedia of Chemical Technology

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This article presents a discussion on three major types of two/three‐phase reactors: bubble column or two/three‐phase sparged reactor, stirred reactor, and venturi loop reactor. The aim is to provide appropriate process design philosophy. The basics of mass transfer accompanied by a chemical reaction are initially presented followed by experimental methods used for discerning reaction kinetics of a multiphase reaction. Metrics for reactor selection have been outlined. A simplified design philosophy that is based on identification of the rate‐controlling step and the associated rate equation has been presented. The intrinsic reaction kinetics do not vary with the type/size of the reactors used. Therefore, the problem reduces to prediction of reactor type and size‐dependent mass transfer coefficients. Subsequent discussion deals with individual reactors with respect to (i) advantages/drawbacks, (ii) areas of application, (iii) hydrodynamic regimes, (iv) gas‐phase holdup, (v) gas–liquid and solid–liquid mass transfer coefficients, k L a and K SL , respectively. The focus is on presenting reliable correlations for k L a and K SL that allow estimation of the rates of corresponding mass transfer steps. Comparison of these with the intrinsic reaction rate yields the rate‐controlling step and associated rate expression for reactor design. The article concludes with a comparison of the performance of the three types chosen for discussion. For the specific reaction chosen, it is concluded that the venturi loop system yields superior performance.

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Gas—Liquid Mass Transfer Coefficient in Stirred Tank Reactors

Cited by 62 publications

References 18 publications

Quantification of power consumption and oxygen transfer characteristics of a stirred miniature bioreactor for predictive fermentation scale‐up

Quantification of power consumption and oxygen transfer characteristics of a stirred miniature bioreactor for predictive fermentation scale‐up

Bioprocess scale‐up: quest for the parameters to be used as criterion to move from microreactors to lab‐scale

Two‐ and Three‐Phase Chemical Reactors

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