Patent ID: 7008528

Claim:
A process for continuously extracting oil from oil-bearing materials in an extraction system, said process comprising: (a) removing air from the extraction system; (b) introducing an inert gas into said extraction system at a pressure sufficient to maintain a normally gaseous solvent in liquid state; (c) introducing an oil-bearing material into a silo; (d) passing said oil-bearing material from said silo to a jet pump mixing device; (e) introducing a liquified normally gaseous solvent into said jet pump mixing device; (f) mixing said oil-bearing material and said solvent in said jet pump mixing device for a time sufficient to permit complete wetting of oil-bearing material by said solvent to form a mixture; (g) heating said mixture to near supercritical conditions; (h) passing said mixture through an extractor having a screw conveyor adapted to rotate at a first rpm range and a centrifugal drum adapted to rotate at a second rpm range; (i) treating said mixture within said extractor in such a manner that supercritical temperature and pressure are attained, wherein treating said mixture includes a combination of increasing the rpms of the centrifugal drum, increasing the temperature inside the extractor and increasing the inert gas pressure inside the extractor; (j) extracting oil from said mixture by pressure diffusion provided by the combination of increased rpms, increased temperatures and increased inert gas pressures at supercritical conditions; (j) removing liquids extracted from said mixture through a liquids exit port, and (k) removing solids extracted from said mixture through a solids exit port.