Methods of Using Ionic Liquids as Demulsifiers

Abstract

A method of demulsifying an emulsion with an ionic liquid having a nitrogen or phosphorus cation.

What is claimed is: 
     
         1 . A method of breaking an emulsion comprising contacting the emulsion with an ionic liquid of the formula:
   R 1 R 2 R 3 R 4 A + X −   (II); or
     R 1 R 2 R 3 A + R 8 A + R 5 R 6 R 7 X −   (III)
   
       wherein:
 A in formula (II) is a nitrogen or a nitrogen heterocyclic ring and wherein each A in formula (III) is independently selected from nitrogen or a nitrogen heterocyclic ring thereof; 
 X is an anion selected from the group consisting of anionic alkoxides; anionic phenols; anionic phenol resins; an anionic homo or copolymer of an oxirane or methyloxirane and mixtures thereof; and 
 R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently selected from the group consisting of hydrogen; benzyl; alkylbenzyl, or oxyalkyl; a straight or branched alkyl group, an alkylbenzyl group, an arylalkyl group, a straight or branched chain alkenyl group, a hydroxyalkyl group or a hydroxyalkylbenzyl group; and a polyoxyalkylene group; and R 8  is a straight or branched alkylene group, an alkylene oxyalkylene, or an alkylene polyoxyalkylene or a zwitterion; and further wherein R groups may be joined to form a heterocyclic nitrogen or phosphorus containing ring. 
 
     
     
         2 . The method of  claim 1 , wherein the ionic liquid is of formula (I) and X is an anionic homopolymer or copolymer of ethylene oxide/propylene oxide. 
     
     
         3 . The method of  claim 2 , wherein X is the anion of a homopolymer or copolymer of the structure: 
       
         
           
           
               
               
           
         
       
       wherein x is independently selected from integer of 1 to 1500. 
     
     
         4 . The method of  claim 2 , wherein X is —(CH 2 CH 2 O) x CH 2 CH(CH 3 )O) y  where x and y are independently selected from 1 to 1500. 
     
     
         5 . The method of  claim 1 , wherein X is selected from the group consisting of anionic alkyl substituted phenols, anionic phenol oxyalkylates and anionic alkyl substituted phenol oxyalkylates. 
     
     
         6 . The method of  claim 5 , wherein the alkyl and oxyalkylate groups contain from 1 to 28 carbon atoms. 
     
     
         7 . The method of  claim 1 , wherein each R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  are independently selected from the group consisting of hydrogen; benzyl; oxyalkyl; a straight or branched C 1-30  alkyl group; a C 7-30  alkylbenzyl group; a C 7-30  arylalkyl group; a straight or branched C 3-30  alkenyl group; a C 1-30  hydroxyalkyl group; a C 7-30  hydroxyalkylbenzyl group; and a polyoxyalkylene group and further wherein R groups may be joined to form a heterocyclic nitrogen containing ring; and R 8  is a straight or branched C 1-30  alkylene, an alkylene oxyalkylene, or an alkylene polyoxyalkylene. 
     
     
         8 . The method of  claim 7 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6  and R 7  of (II) and (III) are independently selected from —H, a C 1-20  alkyl, —CH 2 CH 2 OH, —CH 2 CH(CH 3 )OH, and an oxirane or methyloxirane homo or copolymer containing (CH 2 CH 2 O) x  CH 2 CH(CH 3 )O) 4  where x and y are independently selected from 1 to 1500 and mixtures thereof. 
     
     
         9 . The method of  claim 1 , wherein the emulsion is a water-in-oil emulsion. 
     
     
         10 . The method of  claim 1 , wherein the water-in-oil emulsion is a crude oil emulsion. 
     
     
         11 . The method of  claim 12 , wherein the crude oil emulsion is a refinery desalting emulsion or a crude oil production emulsion. 
     
     
         12 . The method of  claim 3 , wherein the melting point of the ionic liquid is −100° C. to 200° C. 
     
     
         13 . The method of  claim 20 , wherein the ionic liquid and second demulsifier form a reaction product or a synergistic blend. 
     
     
         14 . The method of  claim 1 , wherein:
 (a) the ionic liquid is contacted with the emulsion in a conduit or vessel wherein a hydrocarbon stream is in contact with the conduit or vessel;   (b) the ionic liquid is contacted with the emulsion during storage and/or transportation of a petroleum hydrocarbon fluid;   (c) the ionic liquid is contacted with a hydrocarbon-containing stream at a temperature from about −50° C. to about 250° C. and/or a pressure of about 14.7 psia to about 40,000 psia;   (d) the emulsion is demulsified with the ionic liquid during production or refining of crude oil; or   (e) the emulsion is demulsified with the ionic liquid during removal of metals, amines and/or phosphorus from a petroleum hydrocarbon or an industrial stream.   
     
     
         15 . The method of  claim 1 , wherein the emulsion is a water-in-oil emulsion and further wherein the ionic liquid separates, breaks or resolves oil from the water-in-oil emulsion. 
     
     
         16 . The method of  claim 20 , wherein the demulsifying composition is contacted with the emulsion in a conduit or vessel wherein a hydrocarbon stream is in contact with the conduit or vessel. 
     
     
         17 . The method of  claim 1 , wherein the ionic liquid is a component of a demulsifying composition which further contains a second demulsifier which is not an ionic liquid. 
     
     
         18 . The method of  claim 17 , wherein the ionic liquid enhances the performance of the second demulsifier. 
     
     
         19 . The method of  claim 17 , wherein the demulsifying composition is contacted with the emulsion during storage and/or transportation of a petroleum hydrocarbon fluid. 
     
     
         20 . The method of  claim 17 , wherein the emulsion is demulsified with the demulsifying composition during production or refining of crude oil or during the removal of metals, amines and/or phosphorus from a petroleum hydrocarbon or an industrial stream.