Biotechnology and Bioprocess Engineering

, Volume 11, Issue 3, pp 245–250 | Cite as

Effects of hydrocarbon additions on gas-liquid mass transfer coefficients in biphasic bioreactors

  • Teresa Lopes da Silva
  • Vitor Calado
  • Nadia Silva
  • Rui L. Mendes
  • Sebastião S. Alves
  • Jorge M. T. Vasconcelos
  • Alberto Reis
Article

Abstract

The effects of aliphatic hydrocarbons (n-hexadecane andn-dodecane) on the volumetric oxygen mass transfer coefficient (kLa) were studied in flat alveolar airlift reactor and continuous stirred tank reactors (CSTRs). In the flat alveolar airlift reactor, high aeration rates (>2 vvm) were required in order to obtain efficient organic-aqueous phase dispersion and reliablekLa measurements. Addition of 1% (v/v)n-hexadecane orn-dodecane increased thekla 1.55-and 1.33-fold, respectively, compared to the control (superficial velocity: 25.8×10−3 m/s, sparger orifice diameter: 0.5 mm). Analysis of the gas-liquid interfacial areaa and the liquid film mass transfer coefficientkL suggests that the observedkLa increase was a function of the media's liquid film mass transfer. Addition of 1% (v/v)n-hexadecane orn-dodecane to analogous setups using CSTRs led to akLa increase by a factor of 1.68 and 1.36, respectively (superficial velocity: 2.1×10−3 m/s, stirring rate: 250 rpm). These results propose that low-concentration addition of oxygen-vectors to aerobic microbial cultures has additional benefit relative to incubation in purely aqueous media.

Keywords

flat alveolar airlift bioreactor CSTR oxygen-vector kLa, dodecane hexadecane 

Nomenclature

a

specific interfacial area (1/m)

C*

oxygen saturation concentration of the aqueous phase (g/L)

C

dissolved oxygen concentration of the aqueous phase (g/L)

d32

Sauter mean bubble diameter (m)

deqi

diameter of the volume-equivalent sphere (m)

D

impeller diameter (m)

E

bubble major axis in two-dimensional projection (m)

e

bubble minor axis in two-dimensional projection (m)

kL

liquid film mass transfer coefficient (m/h)

(kl)v

kL in the presence of an oxygen-vector (organic phase) (m/h)

(kL)w

kL in the absence of an oxygen-vector (aqueous phase) (m/h)

kLa

volumetric mass transfer coefficient (1/h)

(kLa)v

kLa in the presence of an oxygen-vector (organic phase) (1/h)

(kLa)w

kLa in the absence of an oxygen-vector (aqueous phase) (1/h)

N

impeller speed (1/s)

P

power (W)

t

time (h)

V

liquid volume (m3)

Greek symbols

δ

sparger orifice diameter (mm)

ε

gas hold up (dimensionless)

Vs

superficial gas velocity (m/s)

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References

  1. [1]
    Ju, L.-K. and C. S. Ho (1989) Oxygen diffusion coefficient and solubility inn-hexadecane.Biotechnol. Bioeng. 34: 1221–1224.CrossRefGoogle Scholar
  2. [2]
    Märl, H. and R. Bronnenmeier (1985) Mechanical stress and microbial production. pp. 369–392. In: H.-J. Rehm and G. Reed (eds.):Biotechnology. VCH, Weinheim, Germany.Google Scholar
  3. [3]
    Déziel, E., Y. Comeau, and R. Villemur (1999) Two-liquidphase bioreactors for enhanced degradation of hydrophobic/toxic compounds.Biodegradation 10: 219–233.CrossRefGoogle Scholar
  4. [4]
    Malinowski, J. J. (2001) Two-phase partitioning bioreactors in fermentation technology.Biotechnol. Adv. 19: 525–538.CrossRefGoogle Scholar
  5. [5]
    Ho, C. S., L.-K. Ju, and R. F. Baddour (1990) Enhancing penicillin fermentations by increased oxygen solubility through the addition ofn-hexadecane.Biotechnol. Bioeng. 36: 1110–1118.CrossRefGoogle Scholar
  6. [6]
    Jia, S., M. Wang, P. Kahar, Y. Park, and M. Okabe (1997) Enhancement of yeast fermentation by addition of oxygen vectors in air-lift bioreactor.J. Ferment. Bioeng. 84: 176–178.CrossRefGoogle Scholar
  7. [7]
    Menge, M., J. Mukherjee, and T. Scheper (2001) Application of oxygen vectors toClaviceps purpurea cultivation.Appl. Microbiol. Biotechnol. 55: 411–416.CrossRefGoogle Scholar
  8. [8]
    Wei, D. Z. and H. Liu (1998) Promotion of L-asparaginase production by usingn-dodecane.Biotechnol. Tech. 12: 129–131.CrossRefGoogle Scholar
  9. [9]
    Giridhar, R. and A. K. Srivastava (2000) Productivity enhancement in 1-sorbose fermentation using oxygen vector.Enzyme Microb. Technol. 27: 537–541.CrossRefGoogle Scholar
  10. [10]
    Jialong, W. (2000) Enhancement of citric acid production byAspergillus niger usingn-dodecane as an oxygen vector.Process Biochem. 35: 1079–1083.CrossRefGoogle Scholar
  11. [11]
    Lai, L. S., T. H. Tsai, and T. C. Wang (2002) Application of oxygen vectors toAspergillus terreus cultivation.J. Biosci. Bioeng. 94: 453–459.Google Scholar
  12. [12]
    Galaction, A. I., D. Cascaval, M. Turnea, and E. Folescu (2005) Enhancement of oxygen mass transfer in stirred bioreactors using oxygen-vectors. 2.Propionobacterium shermanii broths.Bioprocess Biosyst. Eng. 27: 263–271.CrossRefGoogle Scholar
  13. [13]
    MacLean, G. (1977) Oxygen diffusion rates in organic fermentation broths.Process Biochem. 12: 22–28.Google Scholar
  14. [14]
    Lowe, K. C., M. R. Davey, and J. B. Power (1998) Perfluorochemicals: their applications and benefits to cell culture.Trends Biotechnol. 16: 272–277.CrossRefGoogle Scholar
  15. [15]
    Zhao, S., S. Kuttuva, and L. Lu (1999) Oxygen transfer characteristics of multi-phase dispersions simulating water-in-oil xanthan fermentations.Bioprocess Eng. 20: 313–323.CrossRefGoogle Scholar
  16. [16]
    Rols, J. L., J. S. Condoret, C. Fonade, and G. Goma (1990) Mechanism of enhanced oxygen transfer in fermentation using emulsified oxygen-vectors.Biotechnol. Bioeng. 35: 427–435.CrossRefGoogle Scholar
  17. [17]
    Alves, S. S., C. I. Maia, and J. M. T. Vasconcelos (2004) Gas-liquid mass transfer coefficient in stirred tanks interpreted through bubble contamination kinetics.Chem. Eng. Process. 43: 823–830.CrossRefGoogle Scholar
  18. [18]
    Özbek, B. and S. Gayik (2001) The studies on the oxygen mass transfer coefficient in a bioreactor.Process Biochem. 36: 729–741.CrossRefGoogle Scholar
  19. [19]
    Linek, V., P. Benes, J. Sinkule, and T. Moucha (1993) Non-ideal pressure step method fork L a measurement.Chem. Eng. Sci. 48: 1593–1599.CrossRefGoogle Scholar
  20. [20]
    Moucha, T. V., V. Linek, E. Prokopová (2005) Gas holdup, mixing time, and gas-liquid volumetric mass transfer coefficient of various multiple-impeller configurations: Rushton turbine, pitched blade, and techmix impeller and their combinations.Chem. Eng. Sci. 58: 1839–1846.CrossRefGoogle Scholar
  21. [21]
    Silva, T. L., A. Mendes, R. L. Mendes, V. Calado, S. S. Alves, J. M. T. Vasconcelos, and A. Reis (2006) Effect ofn-dodecane onCrypthecodinium cohnii fermentations and DHA production.J. Ind. Microbiol. Biotechnol. 33: 408–416.CrossRefGoogle Scholar
  22. [22]
    Galaction, A. I., D. Cascaval, C. Oniscu, and M. Turnea (2004) Enhancement of oxygen mass transfer in stirred bioreactors using oxygen-vectors. 1. Simulated fermentation broths.Bioprocess Biosyst. Eng. 26: 231–238.CrossRefGoogle Scholar

Copyright information

© The Korean Society for Biotechnology and Bioengineering 2006

Authors and Affiliations

  • Teresa Lopes da Silva
    • 1
  • Vitor Calado
    • 1
  • Nadia Silva
    • 1
  • Rui L. Mendes
    • 2
  • Sebastião S. Alves
    • 3
  • Jorge M. T. Vasconcelos
    • 3
  • Alberto Reis
    • 1
  1. 1.Instituto Nacional de Engenharia, Tecnologia e Inovação, Departamento de BiotecnologiaUnidade de Bioengenharia e BioprocessosLisboaPortugal
  2. 2.Instituto Nacional de Engenharia, Tecnologia e Inovação, Departamento de Energias RenováveisUnidade de BiomassaLisboaPortugal
  3. 3.Instituto Superior Técnico, Departamento de Engenharia Química e BiológicaCentro de Engenharia Biológica e QuímicaLisboaPortugal

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