TITLE: Transition Metal-Graphite Catalysts for Production of Light Hydrocarbons from Synthesis Gas. Quarterly Report, August 1, 1977--October  31, 1977.

AUTHOR: M. P. Rosynek.

INST.  AUTHOR: Texas A and M Univ., College Station. Dept. of Chemistry.

SPONSOR: Department of Energy.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Nov 77,  29p.

ABSTRACT:

Commercial kieselguhr-supported cobalt (containing 39 wt% Co) is an effective catalyst, at 200 to 300 exp 0 C, for the Fischer-Tropsch hydrogenation of carbon monoxide. For reaction in a batch system at a total initial pressure of 1 atm and an initial H sub 2 /CO reactant ratio of 2/1, methane is the major carbon-containing product observed in all cases, with selectivities ranging from approximately 55% at 200 exp 0 C to approximately 90% at 300 exp 0 C. The increase in selectivity to methane with increasing reaction temperature occurs primarily at the expense of the C sub 4+ hydrocarbon fraction which decreases from approximately 30 mole% of the carbon-containing product at 200 exp 0 C to virtually zero at 300 exp 0 C. Production of C sub 2 -C sub 3 hydrocarbons, on the other hand, is affected much less by variations in reaction temperature, remaining relatively constant at 5 to 10% of the total product over the temperature range studied. The total initial rate of carbon monoxide conversion at 250 exp 0 C is approximately 1.2 moles of CO/mole of Co/hr, with a temperature coefficient of 23.8 kcal/mole. The reaction rate decreases with increasing ''time-on-stream'' and stabilizes at only approximately 5% of its initial value after 15 to 20 total hrs of use at 250 exp 0 C and 1 atm. A doubly-promoted catalyst, containing Co : ThO sub 2 : MgO = 31.4 : 1.9 : 3.8 wt% on kieselguhr, exhibited a much higher activity, per cobalt atom, and generated substantially less methane and more C sub 4+ hydrocarbons at 200 to 225 exp 0 C than did the unpromoted cobalt catalyst. However, its use resulted in considerably higher levels of coke deposition and consequent loss of carbon from the gas phase. (ERA citation 03:037042)

CONTRACT  NUMBER: EX-76-C-01-2467