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Controlling the selectivity–stability tradeoff in zeolite catalysis: oligomerization–alkylation, cracking, and methanol-to-hydrocarbons 


    Problem Statement

    Olefins and aromatics are commodity chemicals used in producing plastics (in the petrochemical industry), lubricants, plasticizers, and surfactants, among other products. However, there is an imbalance between their production and demand, which reactions like oligomerization, alkylation, and cracking over zeolites could help address. At the same time, zeolites serve as excellent catalysts for converting methanol to hydrocarbons (MTH), olefins (MTO), or aromatics (MTA). These processes aim to produce light hydrocarbons such as propylene or to convert ethylene into higher-value alpha-olefins, aromatic hydrocarbons (BTX), and jet fuel.


    Our focus in this project is to synthesize, modify, and develop new catalysts with engineered porosity at multiple scales: from hierarchical and hollow zeolites to catalytic particles, bodies, or technical catalysts intended for implementation. Additionally, we incorporate various metals (e.g., Ni, Cr, Zn) to influence the selectivity toward the desired products.

    We utilize various reactors, including forced dynamic, operando, high-throughput packed-bed, and batch reactors.

    OLG-O2H

    Goals

    • Control the catalyst structure to balance selectivity and stability.
    • 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

    Faseeh Kulangara Kandiyil
    Hend Omar Mohamed
    Kiruthika Jayaseelan

    Related Publications

    Dispersing zeolite in technical catalyst particles using a top spray fluidized bed reactor for methanol to hydrocarbons reaction

    by Alkadhem, Mohamed, Hoffmann, Fan, Musteata, Ogg, Ruiz-Martinez, Tsotsas, Castaño
    Chem. Eng. J. Year: 2025 DOI: https://doi.org/10.1016/j.cej.2025.161126

    Abstract

    This work investigates catalyst shaping in top spray fluidized beds and its impact on properties at different levels: particle growth stages, zeolite dispersion within the catalyst particles, and their combined effects on active site accessibility and activity in methanol to hydrocarbons (MTH) reaction. We examine the influence of process parameters such as viscosity, atomization, fluidization, temperature, slurry flow, and initial bed mass on particle size distribution and morphology. Dimensionless number analysis clarifies the dominant growth stage for a given set of process parameters. We elaborate more on optimizing the conditions that maximize zeolite, linked to smaller zeolite size, faster diffusion of probes such as 2, 2-dimethylbutane, and slightly higher activity (without violating the reaction mechanism). By optimizing the dispersion of zeolite through catalyst shaping conditions, we achieved 100 % zeolite utilization, compared to 70 % under non-optimized conditions. This improvement would have a significant impact on scaling this shaping technology.

    Keywords

    HCE O2H