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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

Hend Omar Mohamed
Kiruthika Jayaseelan
Rushana Khairova

Related Publications

Highly productive framework bounded Ni2+ on hierarchical zeolite for ethylene oligomerization

by Mohamed, Velisoju, Hita, Abed, Parsapur, Zambrano, Hassine, Morlanes, Emwas, Huang, Castaño
Chem. Eng. J. Year: 2023 DOI: https://doi.org/10.1016/j.cej.2023.146077

Abstract

The production of higher linear olefins via ethylene oligomerization is an applied industrial process using homogeneous catalysts in the liquid phase. Heterogeneous catalysts based on Ni supported on zeolites are attractive materials for gas phase oligomerization but typically offer a low selectivity or low conversion. Here, we investigate a tailored method to introduce the Ni2+species within the hierarchical zeolite crystallization step (in situ) and compare it with the standard impregnation procedure (ex situ). The in situ engineered catalyst has a very high concentration of Ni2+ species, seamlessly inserted and well dispersed into the zeolite framework, with increased accessibility through meso- and micropores. This catalyst has a unique 1-butene cumulative productivity (32.7 g of 1-butene per g of catalyst) and stability for at least 48 h. This framework bounded Ni2+ promotes oligomerization over isomerization, cracking, and hydride transfer, while the hierarchical zeolite structure enables the discharge of coke precursors. These results pave the way for a more efficient and effective ethylene oligomerization process.

Keywords

OLG HCE