TITLE: Conversion of Low H sub 2 /CO Ratio Synthesis Gas to Hydrocarbons.  Annual Report, October 1, 1981-September 30, 1982.

AUTHOR: A. T. Bell;   H. H. Heinemann.

INST.  AUTHOR: California Univ., Berkeley. Dept. of Chemical Engineering.

SPONSOR: Department of Energy, Washington, DC.


PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  1982,  13p.



The first goals of this project are: (1) to understand the influence of mass transfer on the performance of Fischer-Tropsch slurry reactors, and (2) to determine the nature of carbon formed during reaction. Experiments aimed at the understanding of mass transfer effects have been initiated and are discussed in this report. Fischer-Tropsch synthesis has been carried out in a bubble-column slurry reactor filled with Parawax. A fused-iron catalyst, promoted with potassium and copper, was used for all of the work reported here. The products were analyzed on line by gas chromatography. Experiments have been performed at 250 sup 0 C and 10 atm to determine the dependence of the synthesis rates on the partial pressures of H sub 2 and CO. Following a break-in period, the catalyst activity remained constant over a 4-day period of operation. For each set of partial pressures, a Schulz-Flory distribution of C sub 1 -C sub 10 products was observed. The rate of formation of each product can be described by a power law expression of the form r = kP/sub H sub 2 //sup a/ P/sub CO//sup b/. the value of a is typically 0.9 to 1.0, in excellent agreement with what has been observed for experiments conducted in a well-stirred, slurry reactor using the same catalyst. A positive order CO dependence was observed, with the value of an increasing from 0.05 for CH sub 4 to 0.6 for C sub 4 H sub 8 . These values are in sharp contrast with those found using the well-stirred reactor, where a is negative and increases from -0.4 for CH sub 4 to -0.2 for C sub 4 H sub 8 . The striking difference between the CO dependencies observed between the two reactors is believed to be due to the presence of severe mass-transfer effects in the bubble-column reactor. The validity of the present interpretation is currently being examined very carefully. 5 figs., 1 tab.  (ERA citation 11:055922)