TITLE: Development and process evaluation of improved Fischer-Tropsch slurry catalysts. Final report.

AUTHOR: D. B. Bukur; D. Mukesh; S. A. Patel; W. H. Zimmerman; M. P. Rosynek.

INST.  AUTHOR: Air Products and Chemicals, Inc., Allentown, PA.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNT-RY: United States

SOURCE: Department of Energy [DE],  Apr 90,  353p.

NTIS ORDER NO.: DE95000382INW

ABSTRACT:

This report describes results of a study aimed at developing and evaluating improved catalysts for a slurry Fischer-Tropsch (FT) process for converting synthesis gas to high quality transportation fuels (gasoline and distillate). The improvements in catalyst performance were sought by studying effects of pretreatment conditions, promoters and binders/supports. A total of 20 different, iron based, catalysts were evaluated in 58 fixed bed reactor tests and 10 slurry reactor tests. The major accomplishments and conclusions are summarized below. The pretreatment conditions (temperature, duration and the nature of reducing gas) have significant effect on catalyst performance (activity, selectivity and stability) during Fischer-Tropsch synthesis. One of precipitated unsupported catalysts had hydrocarbon selectivity similar to Mobil's I-B catalyst in high wax mode operation, and had not experienced any loss in activity during 460 hours of testing under variable process conditions in a slurry reactor. The effect of promoters (copper and potassium) on catalyst performance during FT synthesis has been studied in a systematic way. It was found that potassium promotion increases activities of the FT and water-gas-shift (WGS) reactions, the average molecular weight of hydrocarbon products, and suppresses the olefin hydrogenation and isomerization reactions. The addition of binders/supports (silica or alumina) to precipitated Fe/Cu/K catalysts, decreased their activity but improved their stability and hydrocarbon selectivity. The performance of catalysts of this type was very promising and additional studies are recommended to evaluate their potential for use in commercial slurry reactors.

REPORT  NUMBER: DOE/PC/80011-T11

CONTRACT  NUMBER: AC22-85PC80011