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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.

    OLG-O2H

    Goals

    • Control structure–selectivity: Tune zeolite porosity and acidity to maximize propylene and α-olefin yields.
    • Metal modulation: Use Ni, Cr, Zn to bias reaction pathways and improve selectivity to target hydrocarbons.
    • Deactivation control: Reduce coke formation and extend catalyst lifetime with regeneration strategies.
    • Reactor optimization: Shape catalysts into bodies/extrudates and validate 100 h continuous stable operation.

    Related People

    Hend Omar Mohamed
    Kiruthika Jayaseelan

    Related Publications

    Kinetic and Deactivation Differences Among Methanol, Dimethyl Ether and Chloromethane as Stock for Hydrocarbons

    by Valecillos, Manzano, Aguayo, Bilbao, Castaño
    ChemCatChem Year: 2019

    Abstract

    The conversions into hydrocarbons of methanol, dimethyl ether and chloromethane (MTH, DTH and CTH, respectively) on a H‐ZSM‐5 zeolite catalyst were compared trough ab‐initio calculations and experiments, using a fixed‐bed reactor and in‐situ FTIR spectroscopy. The molecular modelling of the reaction was performed using force field calculations. The nature and location of retained species were assessed by a combination of techniques. The experimental results of activity, product distribution and deactivation match these of the molecular modelling as the three reactions proceed through the dual‐cycle mechanism. However, the initiation, evolution and degradation of hydrocarbon pool species are kinetically different depending on the reactant. The reactions are faster in the order DTH>MTH≫CTH whereas the rate at which coke forms and grows (linked with the rate of deactivation) is in the order CTH≫DTH>MTH.

    Keywords

    MKM O2H