SUPERCRITICAL EXTRACTION OF KEROGEN FROM OIL-SHALE.

摘要

The supercritical extraction of Kerogen from Oil-shale was studied both experimentally and theoretically. Experiments were carried out dynamically in a bench scale, fixed-bed type reactor. Oil-shale from Anvil Point Mine (Colorado) was subjected to a continuous-flow extraction with Toluene.;A characteristic dip in the concentration curve is present when the supercritical region (or the two-phase zone) is reached. This behavior was attributed to density changes during the heat-up period of the extraction. Temperature is the most important process variable in the supercritical extraction of Kerogen. A small particle-size effect was found as well as a nonsignificant pressure-effect. Under subpyrolysis temperatures high yield of extraction were obtained (about 65% for a 2.5 hrs period) and no char deposition was observed. Whereas for pyrolysis conditions, severe particle breakage, high char deposition and higher extraction rates were found.;A theoretical extraction model was developed to describe the supercritical extraction of Kerogen from the Oil-shale. The model was solved numerically using a fourth order Runge-Kutta algorithm along with a fully implicit method (finite differences). The extraction model has three adjustable parameters; namely: E;Good agreement was found when the model was fitted to the experimental data. The optimum model parameters found are: ;The Bitumen absorbance was measured continuously in a micro-flow absorption cell. Dispersion effects present between the exit of the reactor and the spectrophotometer were also determined experimentally.