Kinetics of zeolite-catalyzed heptane hydroisomerization and hydrocracking with CBMC-modeled adsorption terms

Zeolite Beta as a large pore base case

Journal article (2022)

Authors

Umang Agarwal Shell Global Solutions International B.V.
Marcello S. Rigutto Shell Global Solutions International B.V.
Erik Zuidema Shell Global Solutions International B.V.
A. P.J. Jansen Shell Technology Centre Bangalore
A. Poursaeidesfahani Process and Energy
S. Sharma Shell Technology Centre Bangalore
David Dubbeldam Universiteit van Amsterdam
T.J.H. Vlugt Engineering Thermodynamics - Mechanical, Maritime and Materials Engineering
Research Group
Engineering Thermodynamics (Mechanical, Maritime and Materials Engineering) (TU Delft)
Copyright: © 2022 Umang Agarwal, Marcello S. Rigutto, Erik Zuidema, A. P.J. Jansen, A. Poursaeidesfahani, S. Sharma, David Dubbeldam, T.J.H. Vlugt
DOI: https://doi.org/10.1016/j.jcat.2022.09.026
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Published Date

2022

Language

English

Faculty

Mechanical, Maritime and Materials Engineering

Department

Process and Energy

Research Group

Engineering Thermodynamics

Abstract

A reactor model that deconvolutes thermodynamics of adsorption of hydrocarbon in the pores of zeolite Beta, obtained by Configurational-bias Monte Carlo simulations, from intrinsic, intraporous kinetics of hydroisomerization and hydrocracking reactions, provides a good quantitative description of all significant reactions in the kinetic network for interconversion and cracking of different heptane isomers. Activation enthalpies obtained for intraporous reactions follow the expected order according to the carbenium ion formalism: methyl shift< ethyl shift < isom(B) ∼ crack(B2) < crack(B1) < crack(C) ∼ crack(D) < crack(E) and apparently within each isomerization class, in terms of carbenium ions formally involved: sec → tert < sec → sec ∼ tert → tert < tert → sec. except for the ethyl shift reaction forming 3-ethylpentane. Cracking happens primarily through 2,4-dimethylpentane (type B2), regardless of the initial reactant. The model can be subsequently used to separate the effect of pore structure on selective adsorption and on intraporous reaction kinetics. Zeolite Beta will serve as a base case for a comparison of different zeolite structures.