TITLE: Chemistry and Morphology of Coal Liquefaction. Annual Report, October 1, 1982-September 30, 1983.

AUTHOR: H. Heinemann.

INST.  AUTHOR: California Univ., Berkeley. Lawrence Berkeley Lab.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Sep 83,  76p.

ABSTRACT:

The kinetics of Fischer-Tropsch synthesis over a potassium-promoted, fused-iron catalyst were studied as a function of catalyst reduction conditions. Severe reduction leads to a very active catalyst, which deactivates rapidly. Milder reduction conditions give a less active but more stable catalyst. Differences in the order of dependence on H sub 2 and CO and the fact that activation energies are independent of reduction condition suggest that different fractions of the surface are brought into an active state. A study of potential support-metal interaction was undertaken. There are significant differences in the product spectrum between fused Fe sub 2 O sub 3 and precipated Fe sub 2 O sub 3 catalysts.  Supported iron on silica, mordenite, y-zeolite and ZSM-5 indicated that chain growth probability is the same for all these supports. Olefin to paraffin ratio increases with increasing Al/Si ratio. Dependencies of rates of formation of individual products on H sub 2 and CO partial pressure are different for each support. Powdered graphite samples loaded with various amounts of KOH have been reacted with atmospheric pressure of steam in the temperature range 700 to 900 exp 0 K. The reaction proceeds via two successive stages. During Stage 1, hydrogen and hydrocarbons are evolved at a high rate but no CO or CO sub 2 . During Stage 2, gasification proceeds catalytically at a much reduced rate with the production of one CO molecule per equivalent H sub 2 molecule. While the results with graphite described indicate a stoichiometric reaction, recent work with an Illinois No. 5 char shows that hydrocarbon production does not stop when all potassium hydroxide has been converted. It appears that an ash component catalytically decomposes the phenolate at reaction temperature, reconstitutes the potassium hydroxide and permits a continuous hydrocarbon production. (ERA citation 09:005672)

REPORT  NUMBER: LBL-16773

CONTRACT  NUMBER: AC03-76SF00098