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U.S. Department of Energy
Office of Scientific and Technical Information

Catalysts for upgrading coal-derived liquids. Final report, September 24, 1979-September 23, 1982

Technical Report ·
OSTI ID:5933771

Significant activity decay and amounts of coke deposits on catalysts were observed in the runs with SRC feedstock. More than half of the catalyst activity loss and coke buildup occurred during the first 40 hours on stream. Coke profiles in the reactor bed showed that the coking reactions were parallel to the main reactions. Mercury porosimetric analyses revealed that pore volumes and pore sizes of the spent catalysts were linearly reduced by the coke on the catalyst. BET nitrogen adsorption showed surface areas of the spent catalysts slightly decreased. All of the catalysts recovered their original surface areas, pore volumes and pore sizes after regeneration. Thus all of these changes in physical properties were the result of coke deposits. Scanning Auger microscopic analyses showed no detectable nitrogen and metal depositions on the spent catalyst surfaces. Moreover, most carbonaceous material deposited within one fifth depth of a catalyst pellet. A parallel fouling model was developed to represent the experimental observations. This model incorporates a variable diffusivity and intrinsic activities as functions of coke deposition. The model is broadly supported by experimental data, and is able to predict catalyst lives based on pore size and pellet size of the catalyst. Catalyst coke content is a good measure of activity. Both hydrogenation and hydrodenitrogenation can be related to coke content, which in turn is a function of time on stream. Successful operation was conducted using Co-Mo-alumnia, Ni-Mo-alumina and their zonal bed combination for hydrotreating Pamco Process solvent oil. Titanocene dichloride added to the SRC light oil feed enhances the restriction formation in the preheating zone where no catalyst is present. This is probably due to polymerization reactions initiated by titanocene dichloride.

Research Organization:
Oklahoma State Univ., Stillwater (USA). School of Chemical Engineering
DOE Contract Number:
AC22-79ET14876
OSTI ID:
5933771
Report Number(s):
DOE/ET/14876-12; ON: DE83016671
Country of Publication:
United States
Language:
English