Deactivation mechanisms for a cobalt molybdate coal liquefaction catalyst
While there are several methods for liquefying coal, those using direct catalytic hydrogenation appear to have some potential advantages. One such process, SYNTHOIL, has been under development by the Pittsburgh Energy Research Center for a number of years. The catalyst in the SYNTHOIL and other processes is multifunctional since it accelerates the rates of heteroatom removal (primarily sulfur) and hydrocracking in the reactor. It consists of cobalt and molybdenum compounds supported on SiO/sub 2/ stabilized/promoted Al/sub 2/O/sub 3/. Such catalysts have a long and successful history as hydrodesulfurization agents in the processing of petroleum-derived feedstocks. For coal liquefaction, their functional activities are very adequate but their lifetimes remain in question. Stanulonis, et.al. have reported on some aspects of the structural and compositional changes accompanying the use of these catalysts in the SYNTHOIL process. In addition, Kang and Johnson have reported on the deactivation mechanisms operative for catalyst in the H-coal process. The object of the present work was to continue the study of catalyst deactivation in the SYNTHOIL process by examining deactivation as a function of time and as a function of position within the reactor. The structural and compositional data indicate that at least four deactivation mechanisms are operative--nitrogen-poisoning, Fe and Ti penetration into the catalyst, surface mineral deposits, and coking within the catalyst. The data indicative of each of these mechanisms is discussed.
- Research Organization:
- Sandia Labs., Albuquerque, NM
- OSTI ID:
- 6926092
- Journal Information:
- Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States), Journal Name: Prepr., Div. Pet. Chem., Am. Chem. Soc.; (United States) Vol. 22:4; ISSN ACPCA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
AUGER ELECTRON SPECTROSCOPY
CATALYSTS
CHEMICAL ANALYSIS
COAL LIQUEFACTION
COBALT
COHERENT SCATTERING
DEACTIVATION
DIFFRACTION
ELECTRON DIFFRACTION
ELECTRON MICROPROBE ANALYSIS
ELECTRON MICROSCOPY
ELECTRON SPECTROSCOPY
ELEMENTS
EMISSION SPECTROSCOPY
LIQUEFACTION
MEASURING INSTRUMENTS
METALS
MICROANALYSIS
MICROSCOPY
MOLYBDENUM COMPOUNDS
OPTICAL MICROSCOPY
POISONING
POROSIMETERS
SCATTERING
SPECTROSCOPY
SYNTHOIL PROCESS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
X-RAY DIFFRACTION