Method for removing fine solids from an aqueous bitumen-containing stream

Abstract

The present invention provides a method for removing fine solids from an aqueous bitumen-containing stream, in particular from an aqueous bitumen-containing stream as obtained during an oil sands extraction process, the method at least comprising the steps of: (a) providing an aqueous bitumen-containing stream; (b) subjecting the aqueous bitumen-containing stream to membrane separation using a ceramic membrane, thereby obtaining a bitumen-depleted permeate stream and a bitumen-enriched retentate stream.

That which is claimed is:  
     
         1 . A method for removing fine solids from an aqueous bitumen-containing stream, in particular as obtained during an oil sands extraction process, the method at least comprising the steps of:
 (a) providing an aqueous bitumen-containing stream;   (b) subjecting the aqueous bitumen-containing stream to membrane separation using a ceramic membrane, thereby obtaining a bitumen-depleted permeate stream and a bitumen-enriched retentate stream.   
     
     
         2 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream comprises at least 85 wt. % water. 
     
     
         3 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream comprises at least 5 ppm bitumen. 
     
     
         4 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream has a dissolved calcium content of at least 10 ppm, as determined according to ASTM D1976-12. 
     
     
         5 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream has a Total Organic Carbon (TOC) of at least 10 ppm. 
     
     
         6 . The method according to  claim 1 , wherein the ceramic membrane has a mean pore size of at most 500 nm. 
     
     
         7 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream has a temperature during step (b) of at least 0° C. 
     
     
         8 . The method according to  claim 1 , wherein the aqueous bitumen-containing stream has a pressure during step (b) of at least 0.5 bara. 
     
     
         9 . The method according to  claim 1 , wherein during step (b) a cross-flow velocity along the surface of the membrane of at least 1.0 m/s is used. 
     
     
         10 . The method according to  claim 1 , wherein the dissolved calcium content of the permeate stream, as determined according to ASTM D1976-12, is reduced by at least 50%, when compared with the aqueous bitumen-containing stream. 
     
     
         11 . The method according to  claim 1 , wherein the permeate stream has a Total Organic Carbon (TOC) of at most 25 ppm, as determined according to APHA 5310A. 
     
     
         12 . The method according to  claim 1 , wherein the permeate stream has a turbidity of at most 5 NTU (normal turbidity units), as determined according to APHA 2130B. 
     
     
         13 . The method according to  claim 1 , wherein the permeate stream has a recovery of at least 40%, when compared with the volume of the aqueous bitumen-containing stream.