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Controlling selectivity and stability of zeolite catalysts for methanol to hydrocarbons and ethylene oligomerization

Problem statement

Olefins are commodity chemicals with applications in the production of plastics (petrochemical industry), lubricants, plasticizers, and surfactants, among many others. However, there is an imbalance between their production and demand, which oligomerization-cracking reactions over zeolites could solve. At the same time, zeolites are excellent catalysts for methanol to hydrocarbons (MTH), olefins (MTO), or aromatics (MTA). The processes aim to produce light hydrocarbons like propylene or convert ethylene into higher-value a-olefins, aromatic hydrocarbons (BTX), and jet fuel.

Our focus in this project is to modify, synthesize and develop novel materials of different porosity (engineered at the multiscale): from hierarchical zeolites, nano zeolites, and hollow zeolites to catalytic particles, bodies, spray-dried and extrudates with tuned properties. Additionally, we incorporate different metals (i.e., Ni, Cr, Zn) to adjust the selectivity of desired products.

We use various reactors, such as operando or high-throughput packed-bed and batch reactors.

Goals

  • Develop a quantitative analytical workflow to analyze and interpret these complex reacting environments
  • Explore novel renewable and waste resources to obtain chemicals and fuels
  • Deploy ad-hoc catalysts and process conditions to incorporate these wastes in the refinery (bio- and waste-refinery)
  • Analyze process dynamics and kinetics
OLG2023

Related People

Related Publications

Simultaneous Modeling of the Kinetics for n-Pentane Cracking and the Deactivation of a HZSM-5 Based Catalyst

by Cordero-Lanzac, Aguayo, Gayubo, Castaño, Bilbao
Chem. Eng. J. Year: 2018

Abstract

A kinetic model for the catalytic cracking of n-pentane over a HZSM-5 zeolite (Si/Al = 15) based catalyst has been proposed. In this model, the kinetic scheme of reactions is based on the paraffin cracking mechanisms and uses lumps (light olefins, light paraffins, C5+ paraffins, aromatics and methane). The reaction steps of the scheme are related with the catalytic cracking routes: protolytic cracking, β-scission, oligomerization-cracking, hydride transfer, olefin condensation and methane formation. In addition, a kinetic deactivation equation has been used for modeling the catalyst deactivation, depending on the coke precursors (light olefins and aromatics) concentration. The catalyst has been prepared by agglomerating the HZSM-5 zeolite with a mesoporous matrix of weak acidity, using pseudoboehmite as a binder. The kinetic runs have been carried out in a fixed bed reactor using the following conditions: 350–550 °C, 1.4 bar, space time up to 1.1 gcat h−1 molC−1 and time on stream up to 15 h. The formation of olefins and aromatics, as well as the catalyst deactivation, are favored at high temperatures. A mathematical methodology based on the Levenberg-Marquardt algorithm has been used for the kinetic parameters estimation. The method has allowed for the simultaneous computing of the kinetic parameters of each step of the reaction scheme and the deactivation kinetics, from the experimental results of evolution with the time on stream of each lump concentration.

Keywords

O2H CHA MKM