A Coupled CFD-Kinetic Models for Cellulase Production in Airlift Reactor

Transcription

1 SigmaFOAM Inc. From the SelectedWorks of Abdelfettah Bannari Ph.D April, 2009 A Coupled CFD-Kinetic Models for Cellulase Production in Airlift Reactor Rachid Bannari Abdelfettah Bannari Brahim Selma Pierre Proulx Available at:

2 A Coupled CFD-Kinetic Models for Cellulase Production in Airlift Reactor 4 th OpenFOAM workshop Montréal, 1-4 june 2009 R. Bannari, A Bannari, B. Selma and P. Proulx Department of Chemical Engineering & Biotechnology Université de Sherbrooke (QC)

3 Outlines Background. Computational and experimental reactor Numerical approach Medium composition Computational and experimental results Conclusion

4 Background Benefit of Ethanol environmental (Use of 10% ethanol-blended fuels ): 30% Reduction in Carbon Monoxide (CO) Emissions. 10% Reduction in Net Carbon Dioxide (CO 2 ) Emissions. economy Energy Security and independence. Economic development opportunity to the rural areas where the ethanol is made.

5 Background Enzyme Production

6 Background Product formation Growth Broth rheology Mass transfer Mixing Complex interactions between morphology, productivity and process conditions in submerged fermentations of filamentous micro-organisms

7 Computational and experimental reactor

8 Computational and experimental reactor

9 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) PBES: bubble size distribution is divided into 7 sections using a geometrical distribution method Coalescence phenomena represent: Coalescence due to different bubble rise velocity. Coalescence due to turbulent eddies. Coalescence due to bubble wake entrainment Breakup phenomena due to turbulent eddies.

10 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) Rheological behavior: We use a fitting of the obtained experimental viscosity.

11 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES 1+ Kinetic Model (species) Species: Species transport is applied, for each phase k={l,g}, to predict the local mass fraction of each species Yik Production/consumption/growth rate Mass transfer between species

12 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) Kinetic: For biomasse growth, a model based on equations like exponential and substrate consumption is taken. The biomass growth rate contains two Monod terms which account for cellulose and lactose and oxygen concentrations: Specific growth rate without substrate limitation (t hours) Saturation constant of substrate

13 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) Kinetic: based on work of Cui et al, 1997 we propose that the specific growth will be composed from the inactivation coefficient of hyphae du to specific energy dissipation rate and the increase of hyphae age: Yield coefficient

14 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) Kinetic: based on work of Kelly et al., 2004 :

15 Numerical approach twophaseeulerfoamspecies : twophaseeuler Foam + PBES + Kinetic Model (species) Kinetic: based on work of Velkovska et al., 1997 we use the enzyme activity rather than protein concentration. Because the solution protein concentration is proportional to cellulase activity. enzyme synthesis rate constant total enzyme secretion Enzyme decay rate constant

16 Numerical approach

17 Numerical approach Server Name : Mammouth-parallel (MP) Type : Parallel Cluster (MPI) Nodes : 576 (Dell 1425SC) Processors : 1152 Intel Xeon, 3.6 GHz Memory : 4 GB / CPU Interconnect : Infiniband 4X Peak performance (measured) : 6,888 Gflops Mp has been Canada's most powerful supercomputer from May 2005 to May 2008

18 Medium composition

19 Numerical results...

20 Numerical results...

21 Numerical results...

22 Numerical results... 14h 24h 48h 72h 80h 140h

23 Numerical results... 1h 14h 24h 72h

24 Numerical results h 140h

25 Conclusion Conclusion A good concordance between the experimental growth and predicted of biomass. A good concordance between the experimental and predicted of enzyme activity. the A good concordance between the experimental and predicted of cellulose consumption. the

26 Thanks! The authors would like to thank the people involved in the development of the OpenFOAM package at the London Imperial college (H. Weller, H, Jasak and H. Rusche in particular) and in general the OpenFOAM community for their generous contributions to the ideas that lead to the continuous development of this package. Special thanks for my supervisor Pr. Pierre Proulx for his support and for the sophisticated materials invested in our Laboratory.

27 Bibliographie 1- Bannari, R., Kerdouss, F., Selma, B., Bannari, A. and Proulx, P. (2008). Three-Dimensional Mathematical Modeling of Dispersed Two-Phase Flow Using Class Method of Population Balance in Bubble Columns. Computers and Chemical Engineering, 32, Aftab, A., Vermette, P., Culture-based strategies to enhance cellulase enzyme production from Trichoderma reesei RUT-C30 in bioreactor culture conditions. Biochemical Engineering Journal, 40, (3), Marten, M. R., Velkovska, S., KHAN, S. A, OLLIS, D. F., (1996). Rheological, mass transfer, and mixing characterization of cellulase-producing Trichoderma reesei suspensions. Biotechnology progress, 1996, 12, Y. Q. Cui, R. G. J. M. van der Lans and K. Ch.A. M. Luyben Effects of dissolved oxygen tension and mechanical forces on fungal morphology in submerged fermentation. Biotechnol. Bioeng Berzins, A., Toma, M., Rikmanis, M. Viesturs, U Influence of Micromixing on Microorganisms and products. Acta Biotechnol, 21, (2), Sven Kelly, Luis H. Grimm, Jan Hengstler, Ellen Schultheis, Rainer Krull, Dietmar C. Hempel, (2004). Agitation effects on submerged growth and product formation of Aspergillus niger. Bioprocess Biosyst Eng, 26,