Why use bubble-column bioreactors?

“…6), biotic TCE conversions could easily be corrected for the small abiotic losses observed (5-10%). Stripping of TCE from the gas phase was found to range, (14) ( и и и ), and models of Heijnen and van 't Riet (1984) and Hikita et al (Merchuk et al, 1994). Figure 6.…”

Section: Tce Removal In the Two-step Systemmentioning

confidence: 93%

Trichloroethene degradation in a two-step system bymethylosinus trichosporium OB3b. Optimization of system performance: Use of formate and methane

Sipkema

Koning

Vlieg

et al. 1999

Biotechnol. Bioeng.

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“…2). sition from the homogeneous regime to the heterogeneous regime takes place at superficial gas velocities of between 0.04 and 0.07 m s −1 (Merchuk et al, 1994). Joshi (1980) showed that their model was still able to predict liquid velocities at superficial gas velocities of 0.05 m s −1 .…”

Section: Vertical-column Reactors: Bubble Columnsmentioning

confidence: 97%

“…The circulation arises from higher gas hold-up values in the center of the column leading to an upward velocity in the center and a downward velocity close to the reactor wall (Merchuk, 1986). The circulatory flows do not cover the whole length of the column but appear to be of the order of the column diameter (T v ) (Merchuk et al, 1994). The circulatory movements of different liquid elements differ considerably.…”

Section: Vertical-column Reactors: Bubble Columnsmentioning

confidence: 99%

Enclosed outdoor photobioreactors: Light regime, photosynthetic efficiency, scale‐up, and future prospects

Janssen

Tramper

Mur

et al. 2002

Biotech & Bioengineering

386

224

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Enclosed outdoor photobioreactors need to be developed and designed for large-scale production of phototrophic microorganisms. Both light regime and photosynthetic efficiency were analyzed in characteristic examples of state-of-the-art pilot-scale photobioreactors. In this study it is shown that productivity of photobioreactors is determined by the light regime inside the bioreactors. In addition to light regime, oxygen accumulation and shear stress limit productivity in certain designs. In short light-path systems, high efficiencies, 10% to 20% based on photosynthetic active radiation (PAR 400 to 700 nm), can be reached at high biomass concentrations (>5 kg [dry weight] m(-3)). It is demonstrated, however, that these and other photobioreactor designs are poorly scalable (maximal unit size 0.1 to 10 m(3)), and/or not applicable for cultivation of monocultures. This is why a new photobioreactor design is proposed in which light capture is physically separated from photoautotrophic cultivation. This system can possibly be scaled to larger unit sizes, 10 to >100 m(3), and the reactor liquid as a whole is mixed and aerated. It is deduced that high photosynthetic efficiencies, 15% on a PAR-basis, can be achieved. Future designs from optical engineers should be used to collect, concentrate, and transport sunlight, followed by redistribution in a large-scale photobioreactor.

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“…24 (242). The measured variable (usually oxygen concentration) is compared with the value that a mathematical model of the process predicts.…”

Section: Mass Transfer Rate Measurementmentioning

confidence: 99%

Bioreactors: Airlift Reactors

Merchuk

Camacho

2010

Encyclopedia of Industrial Biotechnology

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ALRs are popular in modern bioprocess research and development and, in many cases, they have found industrial uses. The distinctive characteristics of ALRs are conferred by the fluid dynamics of the liquid‐gas or liquid gas‐solid mixtures: holdup, liquid velocity, and mixing in the riser, gas separator, and downcomer. Only a correct understanding of the interconnection of these regions can make possible the scale‐up of a laboratory device, to pilot or industrial size. Several correlations are available in the literature for the prediction of the fluid dynamic characteristics of the reactor and of the mass and heat transfer coefficients, and a selection is presented in this review. Significant progress has been made in the application of modern computational tools to the simulation and design of ALRs. In parallel, innovative and sophisticated methods have been applied to obtain a deeper insight into the mechanisms of fluid motion and the flow patterns in the reactor. However, no single research group has managed to cover all the variables over a wide range. The engineer confronting scale‐up or de novo design of an ALR must analyze the validity of the correlations and computation methods used for the calculations.

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Why use bubble-column bioreactors?

Cited by 29 publications

References 33 publications

Trichloroethene degradation in a two-step system bymethylosinus trichosporium OB3b. Optimization of system performance: Use of formate and methane

Trichloroethene degradation in a two-step system bymethylosinus trichosporium OB3b. Optimization of system performance: Use of formate and methane

Enclosed outdoor photobioreactors: Light regime, photosynthetic efficiency, scale‐up, and future prospects

Bioreactors: Airlift Reactors

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