Overall volumetric mass transfer coefficient in a modified reversed flow jet loop bioreactor with low density particles

Prasad, K. Yagna; Ramanujam, T. K.

doi:10.1007/bf01767469

Cited by 5 publications

(5 citation statements)

References 21 publications

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“…4A, Section 2.4). For the JLR the absolute values of the obtained k L a dyn values (k L a dyn (P L /V, u g ) fit to the results obtained by correlation published by Jamshidi et al [37] and Prasad and Ramanujam [36] (Eq. (9)).…”

Section: Comparison Of Str (B1) and Retrofitted Jlr (A1)supporting

confidence: 72%

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Impact of nozzle operation on mass transfer in jet aerated loop reactors. Characterization and comparison to an aerated stirred tank reactor

Weber

Schaepe

Freyer

et al. 2018

Engineering in Life Sciences

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The impact of mass transfer on productivity can become a crucial aspect in the fermentative production of bulk chemicals. For highly aerobic bioprocesses the oxygen transfer rate (OTR) and productivity are coupled. The achievable space time yields can often be correlated to the mass transfer performance of the respective bioreactor. The oxygen mass transfer capability of a jet aerated loop reactor is discussed in terms of the volumetric oxygen mass transfer coefficient kLa [h−1] and the energetic oxygen transfer efficiency E [kgO2 kW−1 h−1]. The jet aerated loop reactor (JLR) is compared to the frequently deployed aerated stirred tank reactor. In jet aerated reactors high local power densities in the mixing zone allow higher mass transfer rates, compared to aerated stirred tank reactors. When both reactors are operated at identical volumetric power input and aeration rates, local kLa values up to 1.5 times higher are possible with the JLR. High dispersion efficiencies in the JLR can be maintained even if the nozzle is supplied with pressurized gas. For increased oxygen demands (above 120 mmol L−1 h−1) improved energetic oxygen transfer efficiencies of up to 100 % were found for a JLR compared to an aerated stirred tank reactor operating with Rushton turbines.

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Section: Comparison Of Str (B1) and Retrofitted Jlr (A1)supporting

confidence: 72%

“…For the JLR the k L a value was correlated using the Sherwood number (Sh), the respective diffusion coefficient (D AB ) and a length scale expressed as diameter (D R ) of the section available for co-current flow of gas and liquid [36,37].…”

Section: Dynamic K L A-measurements Apparatus A1 and B1mentioning

confidence: 99%

Impact of nozzle operation on mass transfer in jet aerated loop reactors. Characterization and comparison to an aerated stirred tank reactor

Weber

Schaepe

Freyer

et al. 2018

Engineering in Life Sciences

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“…. The Sherwood number is the ratio of effective mass transfer to diffusive mass transfer and a variety of correlations for various reactor types and flow regimes is available in the literature . Most commonly they are expressed as a function of the two dimensionless parameters Schmidt ( Sc ) and Reynolds number ( Re ) depicted in Eqs.…”

Section: Resultsmentioning

confidence: 99%

Considerations on film reactivity in the aqueous biphasic hydroformylation

2017

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In experiments and kinetic models it was shown that the reaction rate of the biphasic aqueous hydroformylation of 1octene is linear dependent on the created interfacial area. This phenomenon is directly linked to the question whether the reaction takes place in the bulk phase and is mass transfer limitation or at the surface which would mean an increase of reaction space. To evaluate the place of reaction a mass transfer analysis has been carried out. No mass transfer limitation for the gaseous components carbon monoxide and hydrogen as well as the olefin 1-octene was determined for the aqueous catalyst phase by calculating the Hatta numbers. With this observation it is possible to exclude the mass transfer as a potential influence and hence the aqueous bulk as the place of reaction. Thus the reaction is most probably surface active. This can be either explained the increase in film volume fraction where non-polar substrate as well as polar catalyst complex is present or through an increased catalyst concentration at the surface through dipole moment fluctuations.Experimental Materials 1-Hexene (971%), 1-octene (991%), and 1-decene (95%) were purchased from Acros Organics; 1-dodecene was V tot 5 0.001 m 3 , u 5 0.6, c Rh 5 0.5 mol m 23 aq , P/Rh 5 10, precursor 5 [Rh(cod)Cl]2, T 5 353.15 K, pH 5 5.5, p tot 5 8 MPa, p H2 /p CO 5 1, t 5 1.5 h. 5 163 V tot 5 0.001 m 3 , u 5 0.6, c Rh 5 0.5 mol m 23 aq, P/Rh 5 10, precursor 5 [Rh(cod)Cl]2, T 5 353.15 K, pH 5 5.5, p tot 5 8 MPa, p H2 /p CO 5 1, t 5 1.5 h. 5 V tot 5 0.001 m 3 , u 5 0.6, c Rh 5 0.5 mol m 23 aq, P/Rh 5 10, precursor 5 [Rh(cod)Cl]2, T 5 353.15 K, pH 5 5.5, p tot 5 8 MPa, p H2 /p CO 5 1, t 5 1.5 h. 1HX 5 1-hexene, 1OC 5 1-octene, 1DC 5 1-decene.V tot 5 0.001 m 3 , u 5 0.6, c Rh 5 0.5 mol m 23 aq, P/Rh 5 10, precursor 5 [Rh(cod)Cl]2, T 5 353.15 K, pH 5 5.5, p tot 5 8 MPa, p H2 /p CO 5 1, t 5 1.5 h.

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“…The draft tube diameter is adjusted to achieve maximal mass transfer in the reactor [45][46][47][48]. The design parameters used in this work are defined by Equations 6-9:…”

Section: Experimental Reactor Designmentioning

confidence: 99%

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

Li,

Kowalczyk,

Liessem

et al. 2024

Beilstein J. Org. Chem.

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Photocatalytic hydrogen production from water is a promising way to fulfill energy demands and attain carbon emission reduction goals effectively. In this study, a loop photoreactor with a total volume of around 500 mL is presented for the photocatalytic hydrogen evolution using a Pt-loaded polymeric carbon nitride photocatalyst under 365 nm irradiation in the presence of sacrificial reducing agents. The fluid flow pattern of the developed photoreactor was characterized experimentally and the photon flux incident to the loop photoreactor was measured by chemical actinometry. The system displayed exceptional stability, with operation sustained over 70 hours. A design of experiment (DOE) analysis was used to systematically investigate the influence of key parameters – photon flux, photocatalyst loading, stirring speed, and inert gas flow rate – on the hydrogen generation rate. Linear relationships were found between hydrogen evolution rate and photon flux as well as inert gas flow rate. Photocatalyst loading and stirring speed also showed linear correlations, but could not be correctly described by DOE analysis. Instead, linear single parameter correlations could be applied. Notably, the loop photoreactor demonstrated an external photon efficiency up to 17 times higher than reported in literature studies, while scaling the reactor size by a factor of 10.

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Overall volumetric mass transfer coefficient in a modified reversed flow jet loop bioreactor with low density particles

Abstract: Experiments were conducted using glass beads and Hr m low-density particles such as polyurethane and polystyrene which are comparable to bioparticles found in biological applications to evaluate the overall volumetric mass transfer KL m scoefficient (KLa) List of symbols

Cited by 5 publications

References 21 publications

Impact of nozzle operation on mass transfer in jet aerated loop reactors. Characterization and comparison to an aerated stirred tank reactor

Impact of nozzle operation on mass transfer in jet aerated loop reactors. Characterization and comparison to an aerated stirred tank reactor

Considerations on film reactivity in the aqueous biphasic hydroformylation

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

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