Method for extracting bitumen from an oil sand stream
View Patent ↗The present invention provides a method for extracting bitumen from an oil sand stream, the method including the steps of: (a) providing an oil sand stream; (b) contacting the oil sand stream with a liquid comprising a solvent thereby obtaining a solvent-diluted oil sand slurry; (c) separating the solvent-diluted oil sand slurry, thereby obtaining a first solids-depleted stream and a first solids-enriched stream; (d) filtering the first solids-enriched stream obtained in step (c), thereby obtaining bitumen-depleted sand and at least a first filtrate; (e) separating at least a part of the first filtrate thereby obtaining a second solids-depleted stream and a second solids-enriched stream; and (f) reusing at least a part of the second solids-enriched stream as obtained in step (e) in the contacting of step (b) or the separating of step (c).
1. A method for extracting bitumen from an oil sand stream, the method comprising at least the steps of:
(a) providing an oil sand stream;
(b) contacting the oil sand stream with a liquid, the liquid comprising a solvent thereby obtaining a solvent-diluted oil sand slurry;
(c) separating the solvent-diluted oil sand slurry, thereby obtaining a first solids-depleted stream and a first solids-enriched stream;
(d) filtering the first solids-enriched stream obtained in step (c), thereby obtaining bitumen-depleted sand and at least a first filtrate;
(e) separating at least a part of the first filtrate thereby obtaining a second solids-depleted stream and a second solids-enriched stream; and
(f) reusing at least a part of the second solids-enriched stream as obtained in step (e) in the contacting of step (b).
2. The method of claim 1 , wherein the solvent in step (b) comprises an aliphatic hydrocarbon.
3. The method of claim 2 wherein the aliphatic hydrocarbon has from 3 to 9 carbon atoms per molecule.
4. The method of claim 3 wherein the aliphatic hydrocarbon has from 4 to 7 carbons per molecule.
5. The method of claim 1 wherein the solvent-diluted oil sand slurry obtained in step (b) has a solvent-to-bitumen (S/B) weight ratio of from 0.5 to 1.5.
6. The method of claim 5 wherein the solvent-diluted oil sand slurry obtained in step (b) has a solvent-to-bitumen (S/B) weight ratio of from 0.7 to 1.3.
7. The method of claim 6 wherein the solvent-diluted oil sand slurry obtained in step (b) has a solvent-to-bitumen (S/B) weight ratio of from 0.7 to 1.1.
8. The method of claim 1 wherein the solvent-diluted oil sand slurry obtained in step (b) comprises from 10 to 60 volume percent of solids.
9. The method of claim 8 wherein the solvent-diluted oil sand slurry obtained in step (b) comprises from 20 to 40 volume percent of solids.
10. The method of claim 9 wherein the solvent-diluted oil sand slurry obtained in step (b) comprises from 25 to 35 volume percent of solids.
11. The method of claim 1 wherein the first solids-enriched stream obtained in step (c) comprises from 30 to 70 volume percent of solids.
12. The method of claim 1 wherein the first solids-enriched stream obtained in step (c) comprises above 40 volume percent of solids.
13. The method of claim 1 wherein at least a part of the first solids-depleted stream is reused in the contacting of step (b).
14. The method of claim 1 wherein at least a part of the first solids-depleted stream is combined with the part of the first filtrate to be separated in step (e), thereby obtaining a combined stream.
15. The method of claim 1 wherein the first filtrate has a S/B weight ratio of from 0.5 to 1.5.
16. The method of claim 1 wherein the part of the first filtrate to be separated in step (e) is heated to a temperature in the range of 70 to 130° C.
17. The method of claim 1 wherein a part of the first filtrate is reused in the contacting of step (b).
18. The method of claim 14 , wherein the combined stream to be separated in step (e) has an S/B weight ratio of at least 1.2.
19. The method of claim 1 wherein at least a part of the second solids-enriched stream obtained in step (e) is reused in the filtering of step (d).
20. A method for extracting bitumen from an oil sand stream, the method comprising at least the steps of:
(a) providing an oil sand stream;
(b) contacting the oil sand stream with a liquid, the liquid comprising a solvent thereby obtaining a solvent-diluted oil sand slurry;
(c) separating the solvent-diluted oil sand slurry, thereby obtaining a first solids-depleted stream and a first solids-enriched stream;
(d) filtering the first solids-enriched stream obtained in step (c), thereby obtaining bitumen-depleted sand and at least a first filtrate;
(e) separating at least a part of the first filtrate thereby obtaining a second solids-depleted stream and a second solids-enriched stream; and
(f) reusing at least a part of the second solids-enriched stream as obtained in step (e) in the separating of step (c) by feeding it as a separate stream into a device in which the separation of step (c) takes place.
21. The method of claim 20 , wherein the solvent in step (b) comprises an aliphatic hydrocarbon.
22. The method of claim 21 wherein the aliphatic hydrocarbon has from 3 to 9 carbon atoms per molecule.
23. The method of claim 22 wherein the aliphatic hydrocarbon has from 4 to 7 carbons per molecule.
24. The method of claim 20 wherein the solvent-diluted oil sand slurry obtained in step (b) has a solvent-to-bitumen (S/B) weight ratio of from 0.5 to 1.5.
25. The method of claim 20 wherein the solvent-diluted oil sand slurry obtained in step (b) comprises from 10 to 60 volume percent of solids.