Recovery of oil from tar sand by an improved extraction process

{
  "publication_number": "US3875046A",
  "country": "US",
  "kind": "A",
  "title": "Recovery of oil from tar sand by an improved extraction process",
  "abstract": "An improved process for extracting oil from tar sand containing fines using extraction and phase separation techniques. A closedcycle, single-stage process uses only one extraction vessel in which tar sand is contacted by an extractant, such as water containing a wetting agent and/or a solvent, and recycle water in a fluidized bed condition which avoids disturbing fines attached to the tar sand particles. Fines exiting the extraction vessel in a water phase are agglomerated and reintroduced to the bottom of the extraction vessel where they are filtered out by the extracted sand passing downward in the vessel. The solvent may be vaporized to enhance contact and assure complete recovery. Steam is advantageously introduced to the extraction vessel to scour the sand particles free of solvent. The usual process control additives may be included in the recycle water. The sand and fines tailings are essentially free of pollutants.",
  "claims": [
    "1. IN A PROCESS FOR RECOVERING OIL FROM TAR SAND BY EXTRACTION AND PHASE SEPARATION, THE IMPROVEMENT OF A CLOSED-CYCLE PROCESS COMPRISING: INTRODUCING THE TAR SAND TO A SINGLE-STAGE EXTRACTION VESEL, FLOWING A LIQUID EXTRACTION STREAM INCLUDING WATER COUNTERCURRENT TO THE TAR SAND TO MAINTAIN IT IN A FLUIDIZED BED CONDITION, SEPARATING AN OIL PHASE ABOVE THE TAR SAID FLUIDIZED BED, SEPARATING A WATER PHASE ABOVE THE TAR SAND BUT BELOW THE OIL PHASE, WITHDRAWING A WATER STREAM FROM THE WATER PHASE IN THE EXTRACTION VESSEL, RECYCLING THE WATER STREAM TO THE EXTRACTION VESSEL AT A POINT BELOW THE TOP OF THE TAR SAND FLUIDIZED BED, WITHDRAWING THE SPENT SAND FROM THE EXTRACTION VESSEL, AND WITHDRAWING AN OIL STREAM FROM THE OIL PHASE IN THE EXTRACTION VESSEL.",
    "2. The improved process as claimed in claim 1, further including: introducing steam to the extraction vessel at a point below the fluidized bed, and steam scouring the sand particles to remove therefrom essentially all extraction stream constituents except inert solids.",
    "3. The improved process as claimed in claim 1, wherein the tar sand is introduced into the reaction vessel at a point below the oil phase.",
    "4. The improved process as claimed in claim 1, wherein the tar sand contains fines and the process further includes: maintaining the fluidized bed condition of the tar sand such that effective tar sand-liquid extraction stream contact is provided and the sand is sufficiently suspended to act as a filter media for agglomerated fines, but insufficiently active to dislodge any fines which may be attached to the sand particles, collecting the unattached fines in the separated water phase, withdrawing the fines in the water phase along with the water stream, recycling the water-fines stream to the vessel through introduction thereto at a point below the top of the fluidized bed, removing the fines in the water-fines recycle stream by passing the stream through the sand in the fluidized bed condition to filter them, withdrawing the sand and filtered fines from the vessel, and withdrawing an oil stream, from the oil phase, with reduced content of contaminants such as fines.",
    "5. The improved process as claimed in claim 1, wherein the liquid extraction stream includes dissolved oil extraction control agents selected from the group consisting of wetting agents and dispersing agents.",
    "6. The improved process as claimed in claim 1, wherein the liquid extraction stream includes solvent which is fed to the extraction vessel at a point near the bottom of the fluidized bed and an oil-solvent phase is separated above the fluidized bed.",
    "7. The improved process as claimed in claim 4 further including: passing the withdrawn water-fines stream to a storage and treatment vessel, and agglomerating the fines in the water-fines stream within the storage and treatment vessel prior to recycling the stream of the extraction vessel.",
    "8. The improved process as claimed in claim 1 further including: feeding a solvent to the extraction vessel at a point near the bottom of the fluidized bed, vaporizing the solvent within the extraction vessel, and separating an oil-solvent phase above the fluidized bed.",
    "9. The improved process as claimed in claim 7, further including back washing the sand and fines withdrawn from the extraction vessel prior to dumping the same as tailings in order to assure that they are pollutant-free.",
    "10. The improved process as claimed in claim 4, further including mixing the tar sand with hot water prior to introduction into the extraction vessel, the mixing to be sufficiently gentle to assure that any fines attached to the sand particles are not dislodged therefrom.",
    "11. A closed cycle process for recovering oil from tar sand by extraction and phase separation comprising: introducing the tar sand to a single stage extraction vessel; flowing a liquid extraction stream countercurrent to the tar sand to maintain it in a fluidized bed condition; separating an oil phase above the tar sand fluidized bed; withdrawing an oil stream from the oil phase in the extraction vessel; and withdrawing spent sand from the extraction vessel."
  ],
  "cpc": [
    "C10G 1/047"
  ],
  "ipc": [
    "C10G 1/04"
  ],
  "inventors": [
    "William J Rosenbloom"
  ],
  "filing_date": "1974-04-09",
  "publication_date": "1975-04-01",
  "grant_date": "1975-04-01",
  "priority_date": "1974-04-09",
  "application_number": "US-45926874-A",
  "family_id": "23824086",
  "cited_by_count": 39,
  "citations": [
    "US2885339A",
    "US3075913A",
    "US3553099A",
    "US3619406A"
  ]
}