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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

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Related Publications

Slowing down the deactivation of H-ZSM-5 zeolite catalyst in the methanol-to-olefin (MTO) reaction by P or Zn modifications

by Valecillos, Epelde, Albo, Aguayo, Bilbao, Castaño
Catal. Today Year: 2020

Abstract

The benefits of H-ZSM-5 zeolite modification with H3PO4 or ZnCl2 have been analyzed during the methanol to olefins (MTO) reaction. The catalysts were prepared, characterized and tested using three different reactors: fixed-bed, operando FTIR and UV–vis. The spent catalysts were further characterized for analyzing the nature and location of the species trapped. The results show that the zeolite modified with H3PO4 has suffered a simultaneous dealumination, leading to a decrease of number of acid sites and activity. However, the zeolite modified with ZnCl2 shows the inclusion of Zn transforming Brønsted into Lewis acid sites, leading to reaction intermediates (hydrocarbon pool species) that decreases the rate of reaction but improves propylene selectivity (+10%), slows downs coke formation (-42%) and expands catalytic lifetime (+80%). The distinct effect of Zn modification, typically associated with the promotion of aromatics, is explained on the grounds of the severe transformation of the strong and Brønsted acid sites.

Keywords

O2H HCE CRE