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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

    Controlling Coke Deactivation and Cracking Selectivity of MFI Zeolite by H3PO4 or KOH Modification

    by Epelde, Santos, Florian, Aguayo, Gayubo, Bilbao, Castaño
    Appl. Catal. A: Gen. Year: 2015

    Extra Information

    Open Access.

    Abstract

    The effect of the basic (KOH) or acid (H3PO4) treatment of the MFI (HZSM-5) zeolite has been studied comparing the structural and acidic features with the catalytic performance and deactivation of a set of unmodified and modified zeolites (SiO2/Al2O3 = 30–280, 0–3 wt% of K or P). The properties of the catalysts have been elucidated using XRD, 27Al and 29Si NMR, N2 adsorption–desorption, and adsorption-TPD of tert-butylamine. The catalytic performance has been evaluated in the cracking of 1-butene by means of initial, 5 h on-stream activity and coke formation. Our results point to the fact that using zeolites with high SiO2/Al2O3 ratio or neutralizing the strongest acid sites with KOH or H3PO4 increases propylene selectivity while decreases 1-butene conversion. The overall pathway of reaction involves propylene and other olefins as primary products that condensate in further steps to aromatics and ultimately to coke. This pathway can be controlled with less severe acidic features and by desilication with KOH or H3PO4 (particularly with the former).

    Keywords

    OLG HCE