TITLE: Separation of Fischer-Tropsch Wax from Catalyst by Supercritical Extraction.

AUTHOR: P. C. Joyce; M. C. Thies; D. Sherrard; J. Biales; P. Kilpatrick.

INST.  AUTHOR: USDOE Assistant Secretary for Fossil Energy, Washington, DC

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  31 Jul 97,  17p.

NTIS ORDER NO.: DE98050349INW

ABSTRACT:

Although alkanes are the major constituent of a Fischer-Tropsch wax, significant quantities (e.g., up to 30 wt %) of long-chain alcohol and alkene compounds can also be found in a F-T wax. With the lack of experimental data, the effect that the hydroxy and double-bond functional groups have on the phase behavior of systems containing long- chain hydrocarbons is unknown. Therefore, the phase behavior of the system n-hexane/1-hexadecanol was measured for comparison with the previously measured system n-hexane/hexadecane. Vapor and liquid equilibrium compositions and mixture critical points were measured at 198.9, 251.3, 299.2, and 349.9 deg C at pressures ranging from 6.2 to 46.4 bar.  Temperature and pressure measurements for all isotherms are believed to be accurate to better than +- 3 and 4 percent, respectively. Results indicate that the addition of the alcohol group to a C 16 hydrocarbon chain significantly affects the phase behavior with hexane, with the two-phase region extending to significantly higher (i.e., up to about 10 bar higher) pressures. The presence of an alcohol group was also found to be an impediment to obtaining a good fit of the experimental data with the Peng-Robinson equation.

REPORT  NUMBER: DOE/PC/94219-T10

CONTRACT  NUMBER: FG22-94PC94219