TITLE: Rate and Selectivity Enhancement in Fischer Tropsch Synthesis. Final Technical Report.

AUTHOR: E. Gulari.

INST.  AUTHOR: Michigan Univ., Ann Arbor. Dept. of Chemical Engineering.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  14 Jul 86,  8p.

NTIS ORDER NO.: DE86013014/INW

ABSTRACT:

Overall this project was very successful in proving that one could in fact change the selectivity of a complex reaction such as Fischer Tropsch Synthesis through forced concentration cycling. The basic idea is to change the gas phase composition periodically in order not to allow the catalyst surface to operate at steady state and thus escape the limitations imposed by the kinetics of the rate determining step. With charcoal supported molybdenum catalysts concentration cycling improved both the reactivity and selectivity of the catalysts. In addition to being able to manipulate the carbon number selectivity we were also able to manipulate the olefin to paraffin selectivity of the catalyst. With alumina supported ruthenium catalysts concentration cycling improved the activity of the catalysts much more than the molybdenum based catalysts.  The changes in selectivity however were much more complex. We were successful in enhancing the selectivity to several of the carbon numbers.  Moderate pressure studies showed that the relative rate enhancement and selectivity enhancement increased with pressure. In order to understand the complex behavior of the ruthenium catalyst we also performed in depth transient response studies. Our transient response studies enabled us to measure the changes in the selectivity of the catalyst during concentration cycling. Irrespective of the catalyst we also observed that concentration cycling decreased the rate of catalyst decay very significantly. (ERA citation 11:003989)

REPORT  NUMBER: DOE/PC/70785-T7

CONTRACT  NUMBER: FG22-84PC70785