(90b) Model-Based Design and Intensification of a Catalytic Fluidized Bed Membrane Reactor for Oxidative Coupling of Methane | AIChE

(90b) Model-Based Design and Intensification of a Catalytic Fluidized Bed Membrane Reactor for Oxidative Coupling of Methane

Authors 

Tian, Y., Texas A&M University
Demirhan, C. D., Texas A&M University
De, S., Aditya Birla Science & Technology Company Ltd.
Bavel, A. P. V., Shell Global Solutions International B.V
Pistikopoulos, E., Texas A&M Energy Institute, Texas A&M University
The catalytic oxidative coupling of methane (OCM) process has received growing scientific and commercial interests during the past decades. It offers the potential to directly convert methane to higher hydrocarbons (e.g., ethylene) from natural gas, and consequently reducing the cost, energy consumption, and carbon emissions. However, conventional industrial reactors (e.g., packed bed reactor and fluidized bed reactor) for this process suffer from low ethylene yields, high operating temperatures, and fast catalyst degradation, which hinder the commercialization of this technology (Tiemersma et al., 2012). To drive the innovation in OCM processes, a model-based reactor design approach can be useful for generating the optimal reactor design accounting for novel reactor concepts and benchmark with conventional process solutions.

The aim of this work is to present an optimal OCM process at commercial scale leveraging the concept of modular process intensification. An intensified fluidized bed membrane reactor (FBMR) catalyzed by La2O3/CaO has been investigated, and its performance is compared to a conventional fluidized bed reactor (FBR). Although the utilization of membrane for oxygen feed distribution adds to the capital cost investment and scaling up challenges, it has been reported to result in better ethylene yield and selectivity by selectively enhancing the desired reactions. To systematically identify the optimal design solution, high fidelity FBMR and FBR models are developed in gPROMS ModelBuilder, incorporating the partial differential algebraic equations accounting for mass balances, hydrodynamics, catalyst solid distribution, etc. A micro-kinetic model (with more than 350 elementary reactions) (Dooley et al., 2011) and a 10-step reduced kinetic model (Cruellas et al., 2020) are compared to study the impact of kinetics on reactor modeling and design . The two reactor configurations are optimized to obtain maximum profit, taking into account the design parameters on reactor sizing, temperature, catalyst particle velocity, and membrane tube design (for FBMR). Extensions of the reactor models with operational optimization following the PARametric Optimization and Control (PAROC) framework will also be discussed (Pistikopoulos et al., 2015).

References

Cruellas, A., Melchiori, T., Gallucci, F., & van Sint Annaland, M. (2020). Oxidative Coupling of Methane: A Comparison of Different Reactor Configurations. Energy Technology, 8(8), 1–15. https://doi.org/10.1002/ente.201900148

Dooley, S., Burke, M. P., Chaos, M., Stein, Y., Dryer, F. L., ZHUKOV, V. P., FINCH, O., SIMMIE, J. M., & CURRAN, H. J. (2011). Methyl Formate Oxidation: Speciation Data, Laminar Burning Velocities, Ignition Delay Times, and a Validated Chemical Kinetic Model. International Journal of Chemical Kinetics, 43(3), 154–160. https://doi.org/10.1002/kin

Pistikopoulos, E. N., Diangelakis, N. A., Oberdieck, R., Papathanasiou, M. M., Nascu, I., & Sun, M. (2015). PAROC—An integrated framework and software platform for the optimisation and advanced model-based control of process systems. Chemical Engineering Science, 136, 115–138. https://doi.org/10.1016/J.CES.2015.02.030

Tiemersma, T. P., Chaudhari, A. S., Gallucci, F., Kuipers, J. A. M., & van Sint Annaland, M. (2012). Integrated autothermal oxidative coupling and steam reforming of methane. Part 2: Development of a packed bed membrane reactor with a dual function catalyst. Chemical Engineering Science, 82, 232–245. https://doi.org/10.1016/j.ces.2012.07.047