Liquid purification or separation – Processes – Separating
Patent
1993-11-22
1996-01-02
Dawson, Robert A.
Liquid purification or separation
Processes
Separating
210787, 208390, 208391, 196 1452, C10G 104
Patent
active
054805660
DESCRIPTION:
BRIEF SUMMARY
FIELD OF THE INVENTION
This invention relates to an oil sands separator and a method of separating oil from oil sands.
BACKGROUND OF THE INVENTION
By "oil sands" are meant mineable oil sands of the morphology found in the Athabasca deposits in Northern Alberta, and deposits elsewhere in the world having similar characteristics. To the extent that it may be possible to condition oil and sand combinations found elsewhere, naturally or as a result of oil spills, to have generally similar morphology, the invention is also applicable to such combinations. This morphology and some of its implications from the point of view of separating the bitumen content of the sand are discussed in a paper "Athabasca Mineable Oil Sands: The RTR/Gulf Extraction Process--Theoretical Model of Detachment", A Corti and M. Dente, Paper No. 81, Fourth UNITAR/UNDP Conference on Heavy crude and Tar Sands. A process and apparatus for practically implementing the theory set forth in this paper are described in Canadian Patents Nos. 1,165,712 of RTR Riotinto Til Holding S.A. and 1,167,238 of Ingeco International S.A., discussed further below. For the purposes of the present specification, the entities referred to variously as lumps, particles and matrices in the published art are referred to as granules, to distinguish them on the one hand from sand grains or particles which they contain, and on the other hand from large lumps of oil sand as mined. Such granules consist of a nucleus of sand grains covered with a film of connate water, which may itself contain fine particles, encapsulated, often with gas inclusions, within a layer of the heavy oil known as bitumen, which is essentially solid at ground temperatures. The terms oil and bitumen are used interchangeably in this specification.
The originally developed process for releasing bitumen from tar sands was the Clark hot water process, based on the work of Dr. K. A. Clark, and discussed in the above paper. The Clark process has disadvantages, some of which are discussed in the introductory passage of U.S. Pat. No. 4,946,597, notably a requirement for a large net input of thermal and mechanical energy, complex procedures for separating the released oil, and the generation of large quantities of sludge requiring indefinite storage.
Both the presently used commercial method and apparatus for the separation of oil or bitumen from oil sands based on the Clark process, and the similar process and apparatus described in U.S. Pat. No. 4,946,597, use vigorous mechanical agitation of the oil sands with water and caustic alkali to disrupt the granules and form a slurry, after which the slurry is passed to a separation tank for the flotation of the bitumen from which the bitumen is skimmed. As proposed in the U.S. patent, the process may be operated at ambient temperatures, with a conditioning agent being added to the slurry. Earlier methods, such as the Clark process, used temperatures of 85.degree. C. and above together with vigorous mechanical agitation, and are highly energy inefficient.
It is characteristic of both of the above processes that a great deal of mechanical energy is expended on physically disintegrating the oil sands structure and placing the resulting material in fluid suspension, this disintegration being followed by physical separation of the constituents of the suspension. Chemical adjuvants, particularly alkalis, are utilized to assist these processes. The separation process particularly is quite complex, as will be readily apparent from a study of U.S. Pat. No. 4,946,597, and certain phases have presented particularly intractable problems. Oil sands typically contain substantial but variable quantities of clay, and the very fine particles constituting this clay are dispersed during the process, limiting the degree to which the water utilized in the process can be recovered by flocculation of the clay particles. No economical means has been discovered of disposing of the flocculated and thickened clay particles, which form a sludge which must be stored in sludge ponds wh
REFERENCES:
patent: 889169 (1908-05-01), Trump
patent: 4098648 (1978-07-01), Kraemer et al.
patent: 4512956 (1985-04-01), Robinson et al.
patent: 4533459 (1985-08-01), Dente et al.
patent: 4946597 (1990-08-01), Sury
patent: 4952315 (1990-08-01), Saab
Bitmin Corporation
Dawson Robert A.
Reifsnyder David
LandOfFree
Method for releasing and separating oil from oil sands does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for releasing and separating oil from oil sands, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for releasing and separating oil from oil sands will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-233088