Method for the preparation of viscous hydrocarbon in aqueous buffer solution emulsions

Claim 1

A method for forming stable bimodal emulsions of viscous hydrocarbons in aqueous buffer solutions comprising the steps of: (a) providing a viscous hydrocarbon containing an inactive natural surfactant; (b) forming an aqueous buffer solution comprising water, an alkali additive in an amount of greater than or equal to about 30 ppm and a water soluble amine buffer additive in an amount of greater than or equal to about 4,000 ppm wherein the pH of the aqueous buffer solution is greater than or equal to about 11; (c) mixing the viscous hydrocarbon with the aqueous buffer in a ratio of between about 50:50 to 80:20 at a first mixing energy between about 60,000 and 200,000 J/m 3 so as to form a mono-modal emulsion of viscous hydrocarbon in aqueous buffer solution having an average hydrocarbon droplet size of less than or equal to about 5 microns whereby the buffer additive extracts the inactive natural surfactant from the viscous hydrocarbon so as to stabilize the emulsion; (d) adding water to the mono-modal emulsion so as to form a dilute mono-modal emulsion; and (e) mixing additional viscous hydrocarbon with the dilute mono-modal emulsion at a second miming energy between about 80,000 and 1,000,000 J/m 3 sufficient to form a stable bi-modal emulsion of viscous hydrocarbon in aqueous buffer solution having the following physical and chemical properties: a hydrocarbon to aqueous buffer solution ratio of between about 60:40 to 80:20; an average small hydrocarbon droplet size (D S ) of less than or equal to about 5 microns; and an average large hydrocarbon droplet size (D L ) wherein (D L ) is greater than (D S ) and less than or equal to about 30 microns.

Claim 2

A method for forming stable bimodal emulsions of viscous hydrocarbons in aqueous buffer solutions comprising the steps of: (a) providing a viscous hydrocarbon containing an inactive natural surfactant; (b) forming an aqueous buffer solution comprising water, an alkali additive in an amount of greater than or equal to about 30 ppm and a water soluble amine buffer additive in an amount of greater than or equal to about 4,000 ppm wherein the pH of the aqueous buffer solution is greater than or equal to about 11; (c) mixing the viscous hydrocarbon with the aqueous buffer in a ratio of between about 50:50 to 80:20 at a first mixing energy between about 60,000 and 200,000 J/m 3 so as to form a mono-modal emulsion of viscous hydrocarbon in aqueous buffer solution having an average hydrocarbon droplet size of less than or equal to about 5 microns whereby the buffer additive extracts the inactive natural surfactant from the viscous hydrocarbon so as to stabilize the emulsion; (d) adding water to the mono-modal emulsion so as to form a dilute mono-modal emulsion; and (e) mixing additional viscous hydrocarbon with the dilute mono-modal emulsion at a second miming energy between about 80,000 and 1,000,000 J/m 3 sufficient to form a stable bi-modal emulsion of viscous hydrocarbon in aqueous buffer solution having the following physical and chemical properties: a hydrocarbon to aqueous buffer solution ratio of between about 60:40 to 80:20; an average small hydrocarbon droplet size (D S ) of less than or equal to about 5 microns; and an average large hydrocarbon droplet size (D L ) wherein (D L ) is greater than (D S ) and less than or equal to about 30 microns.