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Packed-Bed Reactor Performance Enhancement by Membrane Distributed Feed: The Case of Methanol Oxidative Dehydrogenation

Published online by Cambridge University Press:  11 February 2011

Victor Diakov  and
Arvind Varma
Victor Diakov
Affiliation:
Department of Chemical Engineering, and Center for Molecularly Engineered Materials University of Notre Dame, Notre Dame, IN 46556, USA
Arvind Varma*
Affiliation:
Department of Chemical Engineering, and Center for Molecularly Engineered Materials University of Notre Dame, Notre Dame, IN 46556, USA
*
* Author to whom correspondence should be addressed Tel: 1–574–631–6491; Fax: 1–574–631–8366; e-mail: [email protected]
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Abstract

For methanol oxidative dehydrogenation to formaldehyde, the performance of the packed-bed membrane reactor (PBMR) is compared with that of the conventional fixed-bed reactor (FBR) over a wide range of operating conditions. The reaction was studied in three reactor configurations: the conventional FBR and the packed-bed membrane reactor, with either methanol (PBMR-M) or oxygen (PBMR-O) as the permeating component. The kinetics of methanol and formaldehyde partial oxidation reactions were determined and incorporated in a PBMR model. Both experimental data and model considerations demonstrate that the PBMR enhances reactant conversion and selectivity.

Small oscillations in CO production were observed experimentally. Their amplitude was taken as a basis for comparison of packed-bed operation instability. The likely source of oscillatory behavior is the non-uniformity in reaction conditions along the reactor. It was found that membrane distributed feed, by providing a more uniform reactor operation, is an effective remedy from these instabilities.

It is found, both by simulations and experimental observations, that relative reactor performance depends strongly on the operating conditions. Using formaldehyde yield as the basis for optimization, optimal reactor performances are determined to be in the order: PBMR-O > FBR > PBMR-M. Further PBMR productivity enhancement is possible by optimizing the membrane feed distribution pattern.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 752: Symposium AA – Membranes–Preparation, Properties and Applications , 2002 , AA13.2
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Santamaria, J.M., Miro, E.E., and Wolf, E.E.. Reactor Simulation Studies of Methane Oxidative Coupling on a Na/NiTiO3 Catalyst. Ind. Eng. Chem. Res., 40, 1157–1165 (1991).Google Scholar
2. Reyes, S.C., Iglesia, E., and Kelkar, C.P.. Kinetic-Transport Models of Bimodal Reaction Sequences – I. Homogeneous and Heterogeneous Pathways in Oxidative Coupling of Methane. Chem. Engng Sci. 48, 2643–2661 (1993).Google Scholar
3. Dixon, A.G.. Innovations in Catalytic Inorganic Membrane Reactors. Catalysis 14, 40–92. Cambridge: Royal Society of Chemistry (1999).Google Scholar
4. Diakov, V.E., Lafarga, D., and Varma, A.. Methanol Oxidative Dehydrogenation in a Catalytic Packed-Bed Membrane Reactor. Catal. Today, 67, 159–167 (2001).Google Scholar
5. Diakov, V.E., Blackwell, B., and Varma, A.. Methanol Oxidative Dehydrogenation in a Catalytic Packed-Bed Membrane Reactor: Reaction Kinetics and Reactor Model. Chem. Engng Sci., 57, 1563–1569 (2002).Google Scholar
6. Al-Juaied, M. A., Lafarga, D., and Varma, A.. Ethylene Epoxidation in a Catalytic Packed-Bed Membrane Reactor: Experiments and Model. Chem. Engng Sci. 56, 395–402 (2001).Google Scholar
7. Razon, L.F., and Schmitz, R.A.. Multiplicities and Instabilities in Chemically Reacting Systems – a Review. Chem. Engng Sci., 42, 1005–1047 (1987).Google Scholar
8. Gray, P., and Scott, S.K., Chemical Oscillations and Instabilities: Non-Linear Chemical Kinetics, pg.5. Oxford: Clarendon Press (1990).Google Scholar
9. Epstein, I.R., and Pojman, J.A., An Introduction to Nonlinear Chemical Dynamics: Oscillations, Waves, Patterns, and Chaos, pg. 23. New York: Oxford University Press (1998).Google Scholar
10. Diakov, V.E., and Varma, A.. Reactant Distribution by Inert Membrane Enhances Packed-Bed Reactor Stability. Chem. Engng Sci., 57, 1099–1105 (2002).Google Scholar
11. Diakov, V.E., and Varma, A.. Methanol Oxidative Dehydrogenation in a Catalytic Packed-Bed Membrane Reactor: Yield Optimization Experiments and Model. Chem. Engng Sci., (2002, in press).Google Scholar
12. Lu, Y., Dixon, A.G., Moser, W.R., and Ma, Y.H.. Oxidative Coupling of Methane in a Modified γ-alumina Membrane Reactor. Chem. Engng Sci., 55, 4901–4912 (2000).Google Scholar
13. Thomas, S., and Seidel-Morgenstern, A.. Selectivity improvement with stagewise adjusted membrane properties. 4th International Conference on Catalysis in Membrane Reactors, Book of Abstracts, Zaragoza, Spain, 29–30 (2000).Google Scholar
14. Ge, S.H., Liu, C.H., and Wang, L.J.. Oxidative Dehydrogenation of Butane using Inert Membrane Reactor with a Non-uniform Permeation Pattern. Chem. Engng J., 84, 497–502 (2001).Google Scholar
15. Diakov, V.E., and Varma, A., “Optimal Feed Distribution in a Packed-Bed Membrane Reactor: The Case of Methanol Oxidative Dehydrogenation,” Ind. Eng. Chem. Res., (2002, in review).Google Scholar