2024 AIChE Annual Meeting

(668c) Microkinetic Modelling of Ethylene Oligomerization on H-BEA Zeolites

Authors

Batchu, S. P. - Presenter, University of Delaware
Cao, B., Purdue University
Gounder, R., Purdue University
Broadbelt, L. J., Northwestern University
To meet the increasing demand in transportation fuels for the next few decades, shale gas is a potential alternative feedstock to crude oil. Transportation fuels are composed of linear and branched alkanes, cycloalkanes, olefins, aromatics (C5 and above), [1,2] and can be produced from shale gas in two steps: 1) coupling of methane or dehydrogenation of ethane/propane to produce ethylene and propylene and, 2) converting ethylene/propylene to higher-C molecules via. oligomerization reactions accompanied by various other reactions such as cyclization, isomerization, aromatization etc. The latter step represents a complex reaction network, entailing myriad of reactions and species, thus making it challenging to construct corresponding microkinetic models and such models are essential to optimize the reaction conditions to obtain maximum yields of desired fuel composition. A way to overcome this challenge is by combining reactions network generation tools, networking pruning rules, and reaction parameterization strategies.

In this work, we build a complex microkinetic model for ethylene oligomerization on H-BEA catalyst to produce paraffins, olefins, dienes, and aromatics up to C10 compounds. We use NetGen [3] to generate the reaction network, prune the reaction network using various reaction rules, parametrize the model using various scaling relationships, and finally, make a predictive model by fitting it to in-house experimental data at various reaction conditions. This model is more complex than the already existing oligomerization models on H-BEA [4,5] which merely pertain to linear paraffins and olefins and low rank products. Our model can potentially propose optimal reaction conditions that not only maximize the yields of desired fuel composition but also mitigate coke formation reactions.

References:

  1. https://www.atsdr.cdc.gov/toxprofiles/tp72-c3.pdf
  2. https://www.atsdr.cdc.gov/ToxProfiles/tp76-c3.pdf
  3. Broadbelt et al., Eng. Chem. Res. 1994, 33 (4), 790–799.
  4. Koninckx et al., Ind. Eng. Chem. Res.2022, 61, 3860−3876
  5. Vernuccio et al., Journal of Catalysis 395 (2021) 302–314