# Implementation of the Vapor–Liquid Equilibrium On the Kinetic Model for the Oligomerization of Olefins

## TL;DR

This paper presents a kinetic model for the oligomerization of olefins that accounts for vapor-liquid equilibrium and catalyst deactivation, enabling accurate simulation of the process.

## Contribution

A novel lump kinetic model combining vapor-liquid equilibrium and concentration-dependent deactivation for simulating olefin oligomerization.

## Key findings

- The model accurately fits experimental data for 1-butene oligomerization under various temperatures and pressures.
- The model explains catalyst deactivation due to pore filling and reconciles observations from prior studies.
- The model demonstrates the effect of liquid retention on catalyst stability and activity.

## Abstract

The oligomerization of light C2–C4 olefins has emerged as one of the most studied processes
for the
sustainable production of different refinery cuts of interest as green
fuels, such as gasoline, diesel, or aviation fuels. However, oligomerization
is a complex process in which the presence of a gas and liquid phase
(heavy oligomers) leads to unique phenomena in this reaction: an apparent
initial deactivation of the catalyst due to the pore filling with
retained oligomers and a steady state of catalyst constant activity.
These features make it difficult to develop robust kinetic models
to simulate the reactor and upscale the process. Herein, a lump kinetic
model has been developed for the simulation of 1-butene oligomerization
in a packed-bed reactor using a catalyst of the HZSM-5 zeolite embedded
in a mesoporous γ-Al2O3 matrix. The computation
methodology is based on a one-dimensional three-phase reactor model
combined with vapor–liquid equilibrium calculations and a concentration-dependent
deactivation equation. The compounds in the gas phase were considered
reactive, while those in the liquid phase were assumed to be retained
in the catalyst pores. The model suitably fitted the experimental
data obtained at 40 bar, different temperatures (150–250 °C),
and space-time values up to 5.7 g h molC
–1. The proposed model reconciled some of the observations in literature
for oligomerization, such as the effect of the retained liquid as
deactivation kinetics distorted by pore diffusion resistance or the
higher stability (high remanent activity) in the presence of the liquid
flow.