Methods and Apparatus for Bitumen Extraction

Abstract

A bitumen extraction method can include the use of a two or more mixing drums aligned in series for spraying solvent over bituminous material and/or tailings loaded in the mixing drums while the mixing drums rotate. Such mixing can result in the dissolution of bitumen into the solvent, which then allows for the separation of a “dilbit” stream from the bituminous material.

1 . A bitumen extraction method comprising:
 feeding a first quantity of bituminous material into a mixing drum;   spraying a solvent over the first quantity of bituminous material inside the mixing drum; and   separating the first quantity of bituminous material into a dilbit stream and a tailings stream.   
     
     
         2 . The method as recited in  claim 1 , wherein the solvent comprises a paraffinic solvent. 
     
     
         3 . The method as recited in  claim 1 , wherein the solvent comprises pentane 
     
     
         4 . The method as recited in  claim 1 , wherein the first quantity and second quantity of bituminous material comprises oil sands. 
     
     
         5 . The method as recited in  claim 1 , further comprising:
 removing the dilbit stream and tailings stream from inside the mixing drum;   feeding a second quantity of bituminous material into the mixing drum; and   spraying the dilbit stream over the second quantity of bituminous material inside the mixing drum.   
     
     
         6 . The method as recited in  claim 1 , further comprising:
 rotating the mixing drum while spraying solvent over the first quantity of bituminous material.   
     
     
         7 . The method as recited in  claim 6 , wherein the mixing drum is rotated at a rate of less than 10 rpm. 
     
     
         8 . The method as recited in  claim 1 , wherein solvent is sprayed over the first quantity of bituminous material at a solvent:bitumen ratio of from 0.5:1 to 3:1 on a volume basis. 
     
     
         9 . The method as recited in  claim 1 , wherein separating the first quantity of bituminous material into a dilbit stream and a tailings stream comprises filtering the dilbit stream from the tailings stream through a screen liner positioned inside of the mixing drum. 
     
     
         10 . The method as recited in  claim 1 , further comprising:
 separating solid material from the dilbit stream.   
     
     
         11 . The method as recited in  claim 10 , wherein separating solid material from the dilbit stream comprises subjecting the dilbit stream to a hydrocyclone, polymeric membrane, or centrifugal separation unit. 
     
     
         12 . The method as recited in  claim 5 , further comprising adding solvent to the dilbit stream or removing bitumen from the dilbit stream prior to spraying the dilbit stream over the second quantity of bituminous material inside the mixing drum. 
     
     
         13 . A bitumen extraction system comprising:
 a mixing drum comprising a solvent inlet, a first dilbit outlet, and a first tailings outlet;   a first separation unit comprising a second dilbit inlet in fluid communication with the first dilbit outlet, a cleaned dilbit outlet, and a solid materials outlet; and   a dilbit storage unit comprising a cleaned dilbit inlet in fluid communication with the cleaned dilbit outlet.   
     
     
         14 . The bitumen extraction system as recited in  claim 13 , wherein the cleaned dilbit outlet is in fluid communication with the solvent inlet of the mixing drum. 
     
     
         15 . The bitumen extraction system as recited in  claim 13 , wherein the mixing drum further includes a liner screen positioned inside of the mixing drum. 
     
     
         16 . A bitumen extraction system comprising:
 a mixing drum comprising a solvent inlet and a slurry outlet;   a hydrocyclone comprising a slurry inlet, a bitumen-depleted tailings outlet, and a dilbit outlet, wherein the slurry inlet is in fluid communication with the slurry inlet of the mixing drum and the dilbit outlet is in fluid communication with the solvent inlet.