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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

    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