Patent ID: 6019912
Filing Date: 2000-02-01
Classification: B01D,C10G

Abstract:
A method for resolving an oil-and-water emulsion, the method comprising adding to the emulsion (1) if the emulsion does not contain polyvalent metal cations in at least a desirably high polyvalent metal cation concentration, said concentration being at least one part per million by weight, an amount of polyvalent metal cations sufficient to produce a treated emulsion having the desirably polyvalent metal cation concentration in the emulsion, and (2) an effective demulsifying amount of a combination of:a. a composition comprising a polydithiocarbamate compound comprising at least two groups represented by the formula --(OR.sup.1).sub.X NHC(:S)SR.sup.2, wherein R.sup.1 represents an alkylene group of 1 to 30 carbon atoms, R.sup.2 represents an alkali metal, an alkaline earth metal, an ammonium group or an amine group, and x represents an integer of from 1 to about 250 independently selected for each of such groups such that the total of the integers x is, on average, from 3 to about 250; thereby to react together in the emulsion at least some of the polyvalent metal cations and the polydithiocarbamate compound to form a polymeric matrix; andb. a terminating agent for increasing the water solubility of the polymeric matrix, selected from the group consisting of:i. non-emulsifying hydrotropes containing a sulfonate group,ii. non-emulsifying hydrotropes containing a sulfate group,iii. coupling agents selected from the group consisting of sulfates of ethoxylated alcohols, sulfates of propoxylated/ethoxylated alcohols, sulfates of ethoxylated phenols, sulfates of propoxylated/ethoxylated phenols, sulfates of ethoxylated amines and sulfates of propoxylated/ethoxylated amines, sulfonates of ethoxylated alcohols, sulfonates of propoxylated/ethoxylated alcohols, sulfonates of ethoxylated phenols, sulfonates of propoxylated/ethoxylated phenols, sulfonates of ethoxylated amines and sulfonates of propoxylated/ethoxylated amines, andvi. mixtures thereof.