Separation of Fischer-Tropsch wax from catalyst using supercritical fluid extraction. Quarterly technical progress report, April 1, 1996--June 30, 1996

The objective of this research project is to evaluate the potential of SCF extraction for separating the catalyst slurry of a Fischer- Tropsch (F-T) slurry bubble column (SBC) reactor into two fractions: (1) a catalyst-free wax containing less than 10 ppm particulate matter and (2) a concentrated catalyst slurry that is ready for recycle or regeneration. The wax will be extracted with a hydrocarbon solvent that has a critical temperature near the operating temperature of the SBC reactor, i.e., 200-300{degrees}C. Initial work is being performed using n-hexane as the solvent. The success of the project depends on two major factors. First, the supercritical solvent must be able to dissolve the F-T wax; furthermore, this must be accomplished without entraining the solid catalyst. Second, the extraction must be controlled so as not to favor the removal of the low molecular weight wax compounds, i.e., a constant carbon-number distribution of the alkanes in the wax slurry must be maintained at steady-state column operation. To implement our objectives, the following task structure is being implemented: Task 1 equilibrium solubility measurements; Task 2 thermodynamic modeling; and Task 3 process design studies. Progress reports are presented for each task