Abstract: A fuel composition having reduced tendency to discoloration at high temperatures comprises kerosine and/or is a jet fuel, and also comprises a cyclic compound comprising m units of the formula 1a.

Abstract: A method for recovering the surfactant from a dispersion or emulsion of oil and water containing a temperature sensitive surfactant which method comprises the steps of heating the dispersion or emulsion to a temperature above the cloud point of the surfactant under conditions of temperature and aqueous phase salinity such that the dispersion or emulsion breaks and separates into an oil layer, an aqueous layer and a surfactant layer, and recovering the surfactant layer.The recovered surfactant may be recycled for use in preparing further quantities of dispersion or emulsion, thus rendering the operation more economic.

Abstract: An HIPR (high internal phase ratio) emulsion of oil in water is prepared by directly mixing 70 to 98% by volume of a viscous oil having a viscosity in the range 200 to 250,000 mPa.s at the mixing temperature with 30 to 2% by volume of an aqueous solution of an emulsifying surfactant or an alkali, percentages being expressed as percentages by volume of the total mixture. Mixing is effected under low shear conditions in the range 10 to 1,000 reciprocal seconds in such manner that an emulsion is formed comprising highly distorted oil droplets having mean droplet diameters in the range 2 to 50 micron separated by thin interfacial films.The emulsions are much less viscous than the oils from which they are prepared and may, optionally after dilution, be pumped through a pipeline.Viscous crude oils may be transported by this method.

Abstract: The salt content of a heavy crude oil is reduced by a method which comprises the steps of(a) mixing 70 to 98% by volume of a heavy crude oil having a viscosity in the range 200 to 250,000 mPa.s at the mixing temperature with 30 to 2% by volume of an aqueous solution of an emulsifying surfactant or an alkali, percentages being expressed as percentages by volume of the total mixture; mixing being effected under low shear conditions in the range 10 to 1,000 reciprocal seconds, in such manner that an HIPR emulsion is formed comprising distorted oil droplets having mean droplet diameters in the range 2 to 50 micron separated by aqueous films,(b) breaking the resulting emulsion, and(c) separating the resulting mixture into a layer of relatively salt-free oil and a layer of relatively salt-enhanced water.Heavy crude oils are desalted by the above method without requiring a hydrocarbon diluent.

Abstract: A continuous method for the preparation of an emulsion of oil in water of desired composition is disclosed which method comprises initially preparing an HIPR emulsion of oil in water by directly mixing 70 to 98% by volume of a viscous oil having a viscosity in the range 200 to 250,000 mPa.s at the mixing temperature with 30 to 2%, by volume of an aqueous solution of an emulsifying surfactant or an alkali, percentages being expressed as percentages by volume of the total mixture; mixing being effected under low shear conditions in the range 10 to 1,000 reciprocal second in such manner that an emulsion is formed comprising distorted oil droplets having mean droplet diameters in the range of 5 to 20 microns separated by aqueous films, measuring the conductivity of the HIPR emulsion, determining the quantity of aqueous liquids to be added as diluent an diluting the HIPR emulsion with the required quantity of diluent.

Abstract: An HIPR emulsion of oil in water is prepared by a method comprising the steps of (a) generating a foam by beating a gas into an aqueous solution of a surfactant and (b) dispersing the foam into the oil under low shear conditions in the range 10 to 1,000 reciprocal seconds in such manner that an emulsion is formed comprising distorted oil droplets having mean droplet diameters in the range 2 to 50 microns, separated by aqueous films, 70 to 98% by volume of the liquid content of the emulsion being oil.The method is applicable to both high and low viscosity oils.Depending on the nature of the oil, the emulsions can be used in the food, drug, cosmetics and petroleum industries.