Supercritical fluid removal of hydrocarbons adsorbed on wide pore zeolite catalysts
The effect of zeolite pore structure on coke removal by supercritical fluid regeneration (SFR) was studied on a series of wide pore zeolite catalysts, which included acidic Y, beta, L, and mordenite zeolites. Catalyst samples were deactivated under liquid phase isobutane/butene alkylation reaction conditions and treated under flowing supercritical isobutane for 60 min. The chemical nature of the species remaining on the catalyst surface before and after SFR was analyzed by temperature-programmed oxidation (TPO), diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), and ultraviolet-visible (UV-Vis) spectroscopy. Zeolite pore structure played an important role not only in hydrocarbon deposition during alkylation but also in hydrocarbon transformation and removal during SFR. During SFR, the formation of unsaturated cyclic or polycyclic compounds, which likely affects catalyst long-term activity after cyclic alkylation/SFR treatments, was hindered on beta zeolites and favored on catalysts containing periodic expansions or cages, such as Y and L zeolites.
- Research Organization:
- Idaho National Lab. (INL), Idaho Falls, ID (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- DE-AC07-99ID-13727
- OSTI ID:
- 912349
- Report Number(s):
- INEEL/JOU-05-02657; JCTLA5; TRN: US200801%%784
- Journal Information:
- Journal of Catalysis, Vol. 234, Issue 2; ISSN 0021-9517
- Country of Publication:
- United States
- Language:
- English
Similar Records
Preparation of metal/zeolite catalysts: Formation of palladium aquocomplexes in the precursor of palladium-mordenite catalysts
Regeneration of a deactivated USY alkylation catalyst using supercritical isobutane