Method of Processing a Bituminous Feed By Staged Addition of a Bridging Liquid

Abstract

The present disclosure relates to a method of processing a bituminous feed. The bituminous feed is contacted with an extraction liquor to form a slurry. A bridging liquid is added to the slurry in at least two stages and solids within the slurry are agitated to form an agglomerated slurry comprising agglomerated solids and a low solids bitumen extract. The agglomerates are then separated from the low solids bitumen extract. Potential benefits may include the production of smaller and more uniform agglomerates. The former may lead to higher bitumen recoveries and the latter may improve the solid-liquid separation rate. The bridging liquid may be added in an area of relatively high shear rates. Between stages of bridging liquid addition, agglomerates may be removed.

1 . A method of processing a bituminous feed, the method comprising:
 a) contacting the bituminous feed with an extraction liquor to form a slurry, wherein the extraction liquor comprises a solvent;   b) adding a bridging liquid to the slurry in at least two stages and agitating solids within the slurry to form an agglomerated slurry comprising agglomerates and a low solids bitumen extract; said bridging liquid being added to the slurry in regions having higher shear rates than a median shear rate within the slurry; and   c) separating the agglomerates from the low solids bitumen extract.   
     
     
         2 . The method of  claim 1 , wherein the regions having higher shear rates than a median shear rate within the slurry are regions adjacent propellers used to agitate the slurry. 
     
     
         3 . The method of  claim 2 , wherein the propellers comprise ports for adding the bridging liquid to the slurry. 
     
     
         4 . The method of  claim 1 , wherein the bridging liquid is one of (i) added in at least two stages in a single agglomerator, (ii) added continuously or intermittently in one or more agglomerators, (iii) added in at least two agglomerators, and (iv) added in at least three stages. 
     
     
         5 .- 6 . (canceled) 
     
     
         7 . The method of  claim 1 , wherein step b) comprises:
 i) adding a first portion of the bridging liquid to the slurry;   ii) agitating solids within the slurry to form agglomerates;   iii) removing agglomerates from the slurry to form a solids-reduced slurry;   iv) adding a second portion of the bridging liquid to the solids-reduced slurry; and   v) agitating solids within the solids-reduced slurry to form agglomerates.   
     
     
         8 . The method of  claim 7 , one of (1) wherein steps i) to v) are performed at least twice, (2) wherein the first portion of the bridging liquid is added to a first agglomerator, the second portion of the bridging liquid is added to a second agglomerator, and agglomerates are removed to form the solids-reduced slurry using a solid-liquid separator and (3) further comprising comminuting removed agglomerates of step iii), wherein one of (i) the comminuting is effected in an attrition scrubber and (ii) the comminuting is effected in a mill. 
     
     
         9 .- 12 . (canceled) 
     
     
         13 . The method of  claim 1 , wherein bridging liquid added during a first stage has one of (i) a salinity that is at least 10% higher or lower than a salinity of a bridging liquid added during a second, subsequent stage and (ii) a suspended solids content that is at least 10% higher or lower than a suspended solids content of a bridging liquid added during a second, subsequent stage. 
     
     
         14 .- 15 . (canceled) 
     
     
         16 . The method of  claim 1 , further comprising recovering the solvent from the low solids bitumen extract to form a bitumen product. 
     
     
         17 . The method of  claim 16 , further comprising washing the agglomerates of step c) with one of (i) the solvent recovered from the low solids bitumen extract and (ii) a solvent, which solvent is the same as or different from the solvent of step a), to extract additional bitumen and to form washed agglomerates. 
     
     
         18 . (canceled) 
     
     
         19 . The method of  claim 17 , further comprising recovering solvent from one of (i) the agglomerates, which have been separated from the low solids bitumen extract and ii the washed agglomerates. 
     
     
         20 . (canceled) 
     
     
         21 . The method of  claim 1 , wherein the extraction liquor comprises the solvent of step a) and bitumen in an amount of 10 to 50 wt %. 
     
     
         22 . The method of  claim 1 , further comprising, prior to step a), contacting the bituminous feed with additional extraction liquor to begin extraction. 
     
     
         23 . The method of  claim 1 , wherein the bridging liquid is one of water and an aqueous solution. 
     
     
         24 . (canceled) 
     
     
         25 . The method of  claim 1 , wherein at least 80 wt. % of the agglomerates of step c) are between 0.1 and 1 mm. 
     
     
         26 . The method of  claim 1 , wherein the agglomerated slurry has a solids content of 20 to 70 wt %. 
     
     
         27 . The method of  claim 1 , wherein the solvent comprises at least one of (i) an organic solvent or a mixture of organic solvents and (ii) a paraffinic solvent, a cyclic aliphatic hydrocarbon, or a mixture thereof. 
     
     
         28 . (canceled) 
     
     
         29 . The method of  claim 27 , wherein the paraffinic solvent comprises an alkane, a natural gas condensate, a distillate from a fractionation unit, or a combination thereof containing more than 40% small chain paraffins of 5 to 10 carbon atoms. 
     
     
         30 . The method of  claim 27 , wherein the alkane comprises one of (i) normal alkane, an isoalkane, or a combination thereof and (ii) heptane, iso-heptane, hexane, iso-hexane, pentane, iso-pentane, or a combination thereof. 
     
     
         31 . (canceled) 
     
     
         32 . The method of  claim 27 , wherein the cyclic aliphatic hydrocarbon comprises a cycloalkane of 4 to 9 carbon atoms, and wherein the cycloalkane comprises cyclohexane, cyclopentane, or a mixture thereof. 
     
     
         33 . (canceled) 
     
     
         34 . The method of  claim 1 , wherein the solvent comprises at least 50 wt. % cyclohexane. 
     
     
         35 . The method of  claim 1 , wherein one of the extraction liquor comprises residual solids and the bridging liquid comprises solid fines, and wherein bridging liquid has a solids content of less than 40 wt % solid fines. 
     
     
         36 .- 37 . (canceled) 
     
     
         38 . The method of  claim 1 , wherein a ratio of the solvent to bitumen in the agglomerated slurry is less than 2:1. 
     
     
         39 . The method of  claim 1 , wherein step b) comprises agitating by mixing, shaking, or rolling. 
     
     
         40 . (canceled) 
     
     
         41 . The method of  claim 1 , wherein a ratio of bridging liquid plus connate water from the bituminous feed to solids within the agglomerated slurry is in the range of 0.02 to 0.25. 
     
     
         42 . (canceled)