Activity and selectivity control on supported cobalt Fischer-Tropsch catalysts

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:43153

Faitao, R A ^[1]; Soled, S L; Iglesia, E; Reyes, S; Via, G; Baumgartner, J ^[2]

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1. Exxon Research and Engineering Co., Florham Park, NJ (United States)
2. Exxon Research and Engineering Co., Annandale, NJ (United States). Corporate Research Labs.

Fischer-Tropsch synthesis in packed-bed reactors requires 1--3 mm pellets in order to minimize pressure gradients through the bed. Studies have shown that CO hydrogenation turnover rates and intrinsic chain growth kinetics depend weakly on Co dispersion and on the identity of the oxide support. In contrast, the authors have found that C5+ selectivity is influenced by dispersion and support, but these effects arise from changes in site density and support structure which modify the rate of intrapellet olefin removal and the extent of olefin readsorption. Studies have demonstrated that added Ru increases the CO turnover rate and C5+ selectivity on a range of supports. In addition the authors have shown that a novel melt impregnation technique coupled with direct slow reduction of the catalyst leads to high cobalt dispersion and high surface site density. The authors have found that maximum C5+ selectivities occur on catalysts with intermediate shell thickness and site density, where olefin readsorption is facilitated, but where intrapellet CO concentration gradients are minimized.

• OSTI ID: 43153
• Report Number(s): CONF-940930--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
10 SYNTHETIC FUELS
CARBON MONOXIDE
CATALYSIS
CATALYST SUPPORTS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTION YIELD
COBALT
FISCHER-TROPSCH SYNTHESIS
METHANATION
MOLECULAR WEIGHT
PENTANOLS
PENTENES
RUTHENIUM