OIL EXTRACTION FROM AUSTRALIAN CONDOR OIL-SHALE WITH WATER AND CO IN THE PRESENCE OF NA2CO3

Extraction of oil from Australian Condor oil shale was carried out in a batch autoclave, heated at a rate of 8.5 K min-1 from room temperature to 673 K and maintained at this temperature for 1 h, in either a water+argon, water+CO or water+CO+Na2CO3 atmosphere. Solvent effect for the extraction decreased in the order water+CO+Na2CO3 to water+CO to water+argon. The oil yield was slightly higher with water+CO than with water+CO+Na2CO3 at a water density of 200 kg m-3. The maximum oil yield (46wt% daf) was obtained under the conditions of water density of 200 kg m-3 (at 673 K) and 1 MPa partial-pressure of CO, when it was charged to the autoclave at room temperature. This oil yield was higher than that (33 wt% daf) of the Fischer assay. It was found from 1H n.m.r. spectra and g.p.c. scans of the oil that the decomposition of kerogen was promoted by CO, and the presence of Na2CO3 suppressed decomposition of the extracted oil into lighter species.