Studies of the Fischer--Tropsch synthesis. XIV. Hagg iron carbide as catalysts

Journal Article · Wed Jan 05 04:00:00 EST 1955 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja01606a079· OSTI ID:5424435

Shultz, J F; Hall, W K; Seligman, B; Anderson, R B

Reduced, fused-iron catalysts were converted to Hagg iron carbide by treatment with either carbon monoxide or 1H/sub 2/ + 4 CO gas, and these carbided catalysts were tested in the Fischer-Tropsch synthesis with 1H/sub 2/ + 1CO gas at pressures varying from 7.8 to 21.4 atmospheres. Carbides prepared with either of the gases had essentially the same activity and selectivity. The initial activities of catalysts converted to Hagg carbide were higher than those of corresponding reduced catalysts. At 7.8, 11.1 and 14.5 atm, the activity of the carbided catalysts was either constant or increased slowly with time. At 21.4 atm, the activity of the carbide decreased rapidly with time. Although the products from carbides had a higher average molecular weight than those from reduced catalysts, it appears that these differences may largely be attributed to variations in operating temperature and not to any major change in the selectivity of the catalyst. There was no drastic change in the selectivity as observed when reduced catalysts are converted to nitrides. The carbides oxidized during synthesis, the rate of oxidation increasing with operating pressure. In most experiments, the total carbon content increased initially and then either remained constant or decreased. The observed composition changes may be explained by two processes: (a) the reaction of water vapor with carbide to produce in one case magnetic and elemental carbon and in the other magnetite and methane; and (b) the reaction of hydrogen with carbidic or elemental carbon to form methane.

• Research Organization: Bureau of Mines, Pittsburgh
• OSTI ID: 5424435
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 77; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
CARBIDES
CARBON COMPOUNDS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
FISCHER-TROPSCH SYNTHESIS
IRON CARBIDES
IRON COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPOUNDS