Investigation of the structure of two-phase flows. Model media in bubble-column bioreactors

Zakrzewski, W.; Lippert, Jürgen; Lübbert, Α.; Schügerl, K.

doi:10.1007/bf01970037

Cited by 17 publications

(2 citation statements)

References 9 publications

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“…Extensive research on gas-liquid contacting has been undertaken in conventional bubble columns and stirred tank vessels [1][2][3][4][5][6][7][8][9][10][11][12][13], and the latter has been the standard device in fermentation industries worldwide. The oscillatory baffled column (OBC) has recently emerged as a viable alternative to those vessels, since it can provide enhanced mass transfer performance [14,15].…”

Section: Introductionmentioning

confidence: 99%

Effect of hydrodynamics on mass transfer in a gas–liquid oscillatory baffled column

Oliveira

2004

Chemical Engineering Journal

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In this paper, we present an experimental study on mass transfer of oxygen into water in an oscillatory baffled column (OBC). The objective of this work is to establish the contribution of individual parameters, such as the size of bubbles and the gas holdup, to the overall volumetric mass transfer coefficient (k L a). Our results show that the gas holdup is the most important factor. The liquid-side mass transfer coefficient (k L ) is calculated directly from the experimental measurements of gas holdup, Sauter mean diameter and k L a, and an increase of k L with D 32 is observed. The results also show that, above a critical level of fluid oscillation, the mass transfer coefficients are mainly governed by the oscillatory operating conditions, while independent of the type of gas sparger.

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Section: Introductionmentioning

confidence: 99%

Effect of hydrodynamics on mass transfer in a gas–liquid oscillatory baffled column

Oliveira

2004

Chemical Engineering Journal

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“…1,2 Several of the studies consider these properties in model media. [3][4][5] The earlier works restricted themselves to the measurement of gas holdup and (seldom) to the bubble size during cultivation (see ref. 5).…”

Section: Introductionmentioning

confidence: 99%

Characterization of the two‐phase systems in airlift tower–loop bioreactors during the cultivation of E. coli

Lippert

Adler

Meyer

et al. 1983

Biotech & Bioengineering

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During the cultivation of E. coli in an airlift tower-loop bioreactor, the following properties were measured: transverse profiles of Sauter bubble diameter, d(S); local relative gas holdup, E(G); bubble rise velocity, u(BS); local mean velocity, ū turbulence intensity, u'; macrotime scale, T(EL); dissipation time scale, tau(E); power spectrum, E(n); and energy dissipation spectrum D(n) at different distances from the aerator. The influence, distance from the aerator, absence and/or presnece of cells, and batch and/or continuous-culture operation on the behavior of the two-phase system are discussed on the basis of these properties.

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Cultivation of E. coli in single‐ and ten‐stage tower–loop reactors

Adler

Schügerl

1983

Biotech & Bioengineering

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E. Coli was cultivated in batch and continuous operations in the presence of an antifoam agent in stirred-tank and in single- and ten-stage airlift tower reactors with an outer loop. The maximum specific growth rate, mu(m), the substrate yield coefficient, Y(x/s), the respiratory quotient, RQ, substrate conversion, U(s), the volumetric mass transfer coefficient, K(L)a, the specific interfacial area, a, and the specific power input, P/V(L), were measured and compared. If a medium is used with a concentration of complex substrates (extracts) 2.5 times higher than that of glucose, a spectrum of C sources is available and cell regulation influences reactor performance. Both mu(m) and Y(X/S), which were evaluated in batch reactors, cannot be used for continuous reactors or, when measured in stirred-tank reactors, cannot be employed for tower-loop reactors: mu(m) is higher in the stirred-tank batch than in the tower-loop batch reactor, mu(m) and Y(x/s) are higher in the continuous reactor than in the batch single-stage tower-loop reactor. The performance of the single-stage is better than that of the ten-stage reactor due to the inefficient trays employed. A reduction of the medium recirculation rate reduces OTR, U(s), Pr, and Y(X/S) and causes cell sedimentation and flocculation. The volumetric mass transfer coefficient is reduced with increasing cultivation time; the Sauter bubble diameter, d(s), remains constant and does not depend on operational conditions. An increase in the medium recirculation rate reduces k(L)a. The specific power input, P/V(L), for the single-stage tower loop is much lower with the same k(L)a value than for a stirred tank. The relationship k(L)a vs. P/V(L) evaluated for model media in stirred tanks, can also be used for cultivations in these reactors.

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Investigation of the structure of two-phase flows. Model media in bubble-column bioreactors

Cited by 17 publications

References 9 publications

Effect of hydrodynamics on mass transfer in a gas–liquid oscillatory baffled column

Effect of hydrodynamics on mass transfer in a gas–liquid oscillatory baffled column

Characterization of the two‐phase systems in airlift tower–loop bioreactors during the cultivation of E. coli

Cultivation of E. coli in single‐ and ten‐stage tower–loop reactors

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