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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

Catalytic Deactivation Pathways During the Cracking of Glycerol and Glycerol/VGO Blends under FCC Unit Conditions

by Errekatxo, Ibarra, Gutierrez, Bilbao, Arandes, Castaño
Chem. Eng. J. Year: 2017

Abstract

The deactivation during the cracking of glycerol into valued chemicals and fuels has been studied under realistic FCC conditions using HZSM-5 or HY zeolite based catalysts. These catalysts suffer a severe catalyst deactivation by coke, which has been characterized quantitatively and qualitatively by TG-TPO, MS/FTIR-TPO, FTIR, 1H and 13C NMR spectroscopies. The first part of this work delves with the product distribution and deactivation of HZSM-5 zeolite based catalyst during the transformation of (pure) aqueous glycerol. The second section focuses on the product distribution and deactivation of HY zeolite based catalyst during the joint cracking of vacuum-gas-oil (VGO) with aqueous glycerol. The results show that the mechanism of deactivation during glycerol cracking, independently of the catalyst used, involves two sequential steps: (i) condensation in the exterior of the zeolite to form an oxygenated coke and (ii) dehydration and hydrogen transfer of the previous oxygenated coke to form a more aromatic one. The second step is only activated at severer conditions (t > 3 s and T > 450 °C). Co-feeding glycerol with VGO increase the yield of coke, gases and decrease the yield of gasoline (with higher octane number), while VGO only participates in the formation of aromatic coke.

Keywords

O2H W2C CRE