Reaction network analysis and kinetics

Reaction network analysis and kinetics

Catalyst preparation, kinetic characterization and modulation of deactivation effects

Demand for propene has been constantly growing in past years since propene is used for the production of a wide variety of chemicals (e.g. polypropylene). Propene is obtained mainly from naphta steam crackers as a co-product with ethene, and as a co-product from gasoline production from fluid catalytic cracking (FCC) units. One of the potential alternatives to deal with the increasing gap between demand and supply is the direct conversion of ethene to propene (ETP-reaction) by using a catalyst constituted of both MCM-41 and AlMCM-41 doped with nickel. This catalytic system is efficient, but faces a severe drawback with fast deactivation with time on stream. Therefore, an alternative is investigated in form of a sequential reactor setup.

 

Ethene to propene (ETP): Catalyst preparation and process concepts

Propene is a central building block in a chemical industry. Nevertheless, there is a gap in the propene market resulting from an increasing demand due to its consumption in the polypropene and propene oxide production. One very promising alternative to increase the availability of propene is the direct conversion of ethene.

3 C2H4 --> 2 C3H6         (ETP- reaction)

Reaction network

  1. Dimerization of ethene (Ni/AlMCM-41 and acid sites)                                   (Cat. 1)
  2. Isomerization of 1-butene (Acid sites)                                                       (Cat. 1)
  3. Metathesis of 2-butene and ethene (NiRe-, Re-, Mo-, W- based catalyst)      (Cat. 2)

Fig. 1: ETP reaction mechanism [1].

The Ni/AlMCM-41 material is an interesting catalyst, capable of performing all three reaction steps at ones, which has been developed previously [1-3]. In the process of intensification of the propene production, a reasonable attempt is the decoupling of the ongoing reaction network.

 

Project goal

Realization of a two-reactor concept (see Fig. 2) with the separation of the metathesis step from the dimerization and isomerization. The work within this project includes also the preparation of the catalysts (see Scheme 1) in a reproducible manner for the two-reactor concept, their characterization with modern techniques, the investigation of catalysts deactivation, reaction network and the determination of reaction kinetics.

Fig. 2: Sequential processes (two-reactor concept) using two catalysts segregated.
Scheme 1: General flexible catalysts preparation procedure.

Characterization equipment

  • Fully automated laboratory equipment for catalytic testing and kinetic measurements with particular catalysts.
  • Nova 2000e surface area and pore size analyzer.
  • Chem Star TPx+ (Quantachrome)  and TPD-R-O (Porotec) equipments(TPR, TPO, pulse chemisorption, TPD).
  • Support by the Faculty of Natural Sciences, Institute of Experimental Physics and the Chemical Institute of the Otto-von-Guericke-University Magdeburg with TEM, EDX, FTIR, MAS-NMR and AAS.

Fig. 3: Conversion of trans-butene (a), conversion of ethene (b) and selectivity of propene (c) for W-SiO2, Re/AlMCM-41 and NiRe-mix(1:1) as a function of the temperature.

Fig. 4: Characterization (Cat. 2) by XRD techniques.

Fig. 5: Characterization (Cat. 2) by H2-TPR techniques.

References

[1] Iwamoto M., (2008), Catal. Surv. Asia 12 pp. 28-37
[2] Lehmann, T.; Wolff, T.; Zahn, V.M.; Veit, P.; Hamel, C.; Seidel-Morgenstern, A.,(2011), "Preparation of Ni-MCM-41 by equilibrium adsorption - Catalytic evaluation for the direct conversion of ethane to propene", Catal. Comm. 12, pp. 368
[3] Lehmann, T.; Wolff, T.; Hamel, C.; Veit, P.; Garke, B.; Seidel-Morgenstern, A., (2012), "Physico-chemical characterization of Ni/MCM-41 synthesized by a template ion exchange", Microporous and Mesoporous Materials 151, pp. 113-125
[4] Alvarado Perea L., Wolff T., Veit P. Hilfert L., Edelmann F.T., Hamel C., Seidel-Morgenstern A., (2013), „Alumino-mesostructured Ni catalysts for the direct conversion of ethane to propene“ Journal of Catalysis, 305, pp. 154-168
[5] Wolff, T.; Felischak, M.; Alvarado-Perea, L.; Hamel, C; Seidel-Morgenstern, A., (2016), „Metathesis of ethene and 2-butene on Re and NiRe based catalysts: Effect of the support”, 49. Jahrestreffen Deutscher Katalytiker, Weimar
[6] Wolff, T., Alvarado-Perea, L., Felischak, M., Hamel, C., Seidel-Morgenstern, A., (2016) „Direct transformation of ethene to propene: study of deactivation of catalysts for two-reactor concept”, Jahrestreffen Reaktionstechnik, Würzburg
[7] Felischak, M., Wolff, T., Alvarado-Perea, L., Seidel-Morgenstern, A., Hamel, C., (2016), „Direct Synthesis of Propene from Ethene Feedstock: Investigation of Catalytic Concepts“, AIChE Annual Meeting San Francisco
[8] Felischak, M., Wolff, T., Alvarado-Perea, L., Lopez Goana, J.A., Seidel-Morgenstern, A., Hamel, C., (2017) „Investigation of prolonged Ni/(Al)MCM-41 application under reaction conditions for the production of propene from ethene”, 50. Jahrestreffen Deutscher Katalytiker, Weimar
[9] Wolff, T., Felischak, M., Alvarado-Perea, L., Lopez Goana, J.A., Hamel, C., Seidel-Morgenstern, A., (2017), „Experimental investigation of the metathesis of ethene and 2-butene using metallic catalysts supported on mesoporous material”, 50. Jahrestreffen Deutscher Katalytiker, Weimar
[10] Felischak, M., Wolff, T., Alvarado-Perea, L., Lopez Goana, J.A., Seidel-Morgenstern, A., Hamel, C., (2017), „Mechanistic Investigation of propene production from ethene feed for long time on stream using Ni/(Al)MCM-41”, Jahrestreffen Reaktionstechnik, Würzburg
[11] Wolff, T., Felischak, M., Alvarado-Perea, L., Lopez Goana, J.A., Hamel, C., Seidel-Morgenstern, A., (2017),  „Deactivation study of Mo, W, Re and NiRe on mesoporous support for metathesis of ethene and 2-butene”, Jahrestreffen Reaktionstechnik, Würzburg
[12] Alvarado-Perea, L., Wolff, T., Hamel, C., Seidel-Morgenstern, A., (2017) „Experimental study of the deactivation of Ni/AlMCM-41 catalysts in the direct conversion of ethene to propene”, Applied Catalysis A: General, 533, pp. 121-131
[13] Alvarado-Perea, L., Felischak, M., Wolff, T., Hamel, C., Seidel-Morgenstern, A., (2017) „Experimental Investigation of the Reaction Network of Ethene to Propene over Ni/AlMCM-41 Catalysts”, Chemie-Ingenieur-Technik, 89, pp. 903-914
[14] Felischak, M., Wolff, T., Alvarado-Perea, L., Seidel-Morgenstern, A., Hamel, C., (2018) „Kinetic Investigation of propene production under metathesis conditions applying W/SiO2”, 51. Jahrestreffen Deutscher Katalytiker, Weimar
[15] Felischak, M., Seidel-Morgenstern, A., Hamel, C., (2018) „Conceptual study of the ethene to propene reaction carried out in a reactor cascade”, Jahrestreffen Reaktionstechnik, Würzburg
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