Separating cycloalkanes using aqueous solutions of cucurbituril macrocycles

Abstract

Embodiments of the present disclosure include methods for separating cycloalkanes comprising contacting a petroleum solution including one or more cycloalkanes with an aqueous solution including a cucurbituril macrocycle to produce a first aqueous phase and a first organic phase, wherein the cucurbituril macrocycle is selective for extraction of at least one of the one or more cycloalkanes.

What is claimed is: 
     
         1 . A method of separating cycloalkanes comprising:
 contacting a petroleum solution including one or more cycloalkanes with an aqueous solution including a cucurbituril macrocycle to produce a first aqueous phase and a first organic phase, wherein the cucurbituril macrocycle is selective for extraction of at least one of the one or more cycloalkanes.   
     
     
         2 . The method according to  claim 1 , wherein the one or more cycloalkanes includes one or more of cyclohexane, methylcyclohexane, and methylcyclopentane. 
     
     
         3 . The method according to  claim 1 , wherein the petroleum solution further contains one or more of linear hydrocarbons, branched hydrocarbons, and aromatic hydrocarbons and wherein the cucurbituril macrocycle is selective for the extraction of at least one of the one or more cycloalkanes over the one or more of linear hydrocarbons, branched hydrocarbons, and aromatic hydrocarbons. 
     
     
         4 . The method according to  claim 1 , wherein the cucurbituril macrocycle has the following chemical structure: 
       
         
           
           
               
               
           
         
         wherein: 
         a 1  indicates a point of attachment to b 1 ; 
         a 2  indicates a point of attachment to b 2 ; 
         n is 1-20; 
         X is O, S, or NH; and 
         R 1  and R 2  are independently selected from the group consisting of hydrogen, H, optionally substituted C 1 -C 30  alkyl group; optionally substituted C 2 -C 30  alkenyl group; optionally substituted C 2 -C 30  alkynyl group; optionally substituted C 2 -C 30  carbonylalkyl group; optionally substituted C 1 -C 30  thioalkyl group; optionally substituted C 1 -C 30  alkylthiol group; optionally substituted C 1 -C 30  hydroxyalkyl group; optionally substituted C 1 -C 30  alkylsilyl group; optionally substituted C 1 -C 30  aminoalkyl group; optionally substituted C 1 -C 30  aminoalkylthioalkyl group; optionally substituted C 5 -C 30  cycloalkyl group; optionally substituted C 2 -C 30  heterocycloalkyl group; optionally substituted C 6 -C 30  aryl group; optionally substituted C 6 -C 30  arylalkyl group; optionally substituted C 4 -C 30  heteroaryl group; and optionally substituted C 4 -C 30  heteroarylalkyl group. 
       
     
     
         5 . The method according to  claim 4 , wherein n is 7. 
     
     
         6 . The method according to  claim 4 , wherein n is 6. 
     
     
         7 . The method according to  claim 4 , wherein n is 7. 
     
     
         8 . The method according to  claim 4 , wherein X is 0. 
     
     
         9 . The method according to  claim 4 , wherein R 1  and R 2  are H. 
     
     
         10 . The method according to  claim 1 , wherein contacting the petroleum solution with the aqueous solution causes at least a portion of the at least one of the one or more cycloalkanes to be transferred from the petroleum solution to the aqueous solution. 
     
     
         11 . The method according to  claim 10 , wherein the portion of the at least one of the one or more cycloalkanes is transferred from the petroleum to the aqueous solution through formation of a host-guest complex comprising a host and a guest and wherein the cucurbituril macrocycle is the host and the portion of the at least one of the one or more cycloalkanes is the guest. 
     
     
         12 . The method according to  claim 11 , wherein the first aqueous phase includes the host-guest complex; and wherein the first organic phase includes the petroleum solution, the petroleum having a reduced concentration of the at least one of the one or more cycloalkanes. 
     
     
         13 . The method according to  claim 12 , further comprising recovering at least a portion of the at least one of the one or more cycloalkanes from the first aqueous phase using an organic solution to produce a second aqueous phase and a second organic phase. 
     
     
         14 . The method according to  claim 13 , wherein the second aqueous phase includes at least a portion of the cucurbituril macrocycle from the first aqueous phase, and wherein the second organic phase includes the portion of the at least one of the one or more cycloalkanes recovered from the first aqueous phase. 
     
     
         15 . The method according to  claim 14 , further comprising recycling the second aqueous phase for use in one or more separation cycles. 
     
     
         16 . A liquid-liquid extraction solvent comprising: an aqueous solution of a cucurbituril macrocycle, wherein the cucurbituril macrocycle is selective for the extraction of at least one cycloalkane and wherein the cucurbituril has the following chemical structure: 
       
         
           
           
               
               
           
         
         wherein: 
         a 1  indicates a point of attachment to b 1 ; 
         a 2  indicates a point of attachment to b 2 ; 
         n is 1-20; 
         X is O, S, or NH; and 
         R 1  and R 2  are independently selected from the group consisting of hydrogen, H, optionally substituted C 1 -C 30  alkyl group; optionally substituted C 2 -C 30  alkenyl group; optionally substituted C 2 -C 30  alkynyl group; optionally substituted C 2 -C 30  carbonylalkyl group; optionally substituted C 1 -C 30  thioalkyl group; optionally substituted C 1 -C 30  alkylthiol group; optionally substituted C 1 -C 30  hydroxyalkyl group; optionally substituted C 1 -C 30  alkylsilyl group; optionally substituted C 1 -C 30  aminoalkyl group; optionally substituted C 1 -C 30  aminoalkylthioalkyl group; optionally substituted C 5 -C 30  cycloalkyl group; optionally substituted C 2 -C 30  heterocycloalkyl group; optionally substituted C 6 -C 30  aryl group; optionally substituted C 6 -C 30  arylalkyl group; optionally substituted C 4 -C 30  heteroaryl group; and optionally substituted C 4 -C 30  heteroarylalkyl group. 
       
     
     
         17 . The solvent according to  claim 16 , wherein n is 7. 
     
     
         18 . The solvent according to  claim 16 , wherein X is 0. 
     
     
         19 . The solvent according to  claim 16 , wherein R 1  and R 2  are H.