TITLE: Study of Fischer-Tropsch Synthesis over a Silica Supported Iron Catalyst Through the Use of Reactive Scavengers.

AUTHOR: C. J. Wang.

INST.  AUTHOR: Texas Univ. at Austin.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  Aug 83,  115p.

ABSTRACT:

The synthesis of hydrocarbons from H sub 2 and CO was studied on a silica-supported Fe catalyst. The synthesis was carried out at 1.54 atm and 200 to 255 exp 0 C in a differential reactor. Conversion of CO never exceeded 2%. The working catalyst was achieved by transforming Fe sub 2 O sub 3 into a mixture of Fe sub 3 O sub 4 , bulk carbides, and iron under synthesis conditions. Synthesis product distributions and the rate of methane formation are reported. Trends in CO sub 2 formation and the presence of cyclic hydrocarbons, saturated and unsaturated, suggest the  presence of some Fe sub 3 O sub 4 at the catalyst surface. Cyclohexene addition to the feed generated low concentrations of alkyl-substituted cyclohexene and cyclohexanes. Pyridine addition to the feed generated alkyl-substituted pyridines. Scavenged products were not formed from interactions between the scavenger and synthesis products on support, indicating that the scavengers react with species involved in chain propagation. Pyridine was used to scavenge C sub 1 to C sub 3 alkyl species from the catalyst surface. The alpha -alkylpyridine distributions were proportional to the dependence of C sub 1 to C sub 3 Fischer-Tropsch products. Two probable Fischer-Tropsch mechanisms were derived. (ERA citation 08:048768)

REPORT  NUMBER: DOE/ER/10720-11

CONTRACT  NUMBER: AS05-80ER10720