The invention relates to an oil-in-water emulsion comprising an oil phase and an aqueous phase, and a primary surfactant, wherein the oil phase is dispersed in the aqueous phase, and wherein the oil-in-water emulsion has: an average droplet size distribution (D[4,3]) in the range of from 3 to 15 m and less than 3 wt % of the droplets have a particle size of greater than 125 m; a viscosity of greater than 100 and up to 700 mPas at 50 C.10% and 20 s.sup.110%; and a static stability of less than 5% residue after centrifugation at 50 C.10% and 2000 g=10% for 30 minutes10%. A process for preparing such an oil-in-water emulsion comprises preparing an aqueous phase comprising a primary surfactant, heating a hydrocarbon-containing oil-phase, and blending the hydrocarbon-containing oil and the aqueous phase under conditions sufficient to form an oil-in-water emulsion. The invention also relates to methods for determining the static and dynamic stability of oil-in-water emulsions. Static stability can be determined by a method comprising the steps of: providing an oil-in-water emulsion; centrifuging the oil-in-water emulsion under predetermined conditions for a predetermined period of time; determining the amount of residue deposited from the oil-in-water emulsion after the predetermined period of time; and determining the oil-in-water emulsion's static stability. A method for determining the dynamic stability of an oil-in-water emulsion comprises the steps of: providing an oil-in-water emulsion; analysing the oil-in-water emulsion at a first time; recirculating the oil-in-water emulsion in a recirculation loop; and analysing the oil-in-water emulsion at second time after recirculation has started; in which the oil-in-water emulsion's dynamic stability is determined based on the analysis at the first and second times.

An emulsion comprising water and an immiscible predominantly hydrocarbon-based liquid, wherein the emulsion further comprises at least one protein for inhibiting the growth of microorganisms, said protein containing or being capable of binding to one of: a monosaccharide and an oligosaccharide. Uses of the invention include, but are not limited to: applications in oil well/fracking operations where it is necessary or desirable to neutralise bacteria in the extracted liquid; as an additive emulsion for bio-diesel to reduce emissions, such as NOx etc.; and as an additive in the water of heating/cooling systems for its biocidal properties.

A method for powering a diesel engine with a fuel emulsion involves preparing the fuel emulsion by emulsifying a fuel and water in the presence of an emulsifier package, which contains a branched surfactant of the formula (I) as defined below and optionally, a propoxylated surfactant of the formula (II) as defined below. A fuel emulsion for powering a diesel engine is also provided.

A method for powering a diesel engine with a fuel emulsion involves preparing the fuel emulsion by emulsifying a fuel and water in the presence of an emulsifier package, which contains a short-chained surfactant of the formula (I) as defined below and optionally, a long-chained surfactant of the formula (II) as defined below. A fuel emulsion for powering a diesel engine is also provided.

Aqueous dispersion of paraffine inhibitors, comprising a continuous aqueous phase comprising water and a water-miscible organic solvent, a dispersed phase comprising at least one paraffin inhibitor component, and at least one anionic surfactant, methods of manufacturing such aqueous dispersions, and the use of such aqueous dispersions as paraffin inhibitor or pour point depressant for crude oil or other hydrocarbon fluids, such as fuel oils or diesel.

Provided are an emulsion fuel supply device capable of stably driving a combustion apparatus with a simple device configuration, and a supply method of an emulsion fuel. A device 1 is a device for supplying the emulsion fuel to a combustion apparatus 70, including a processed water generation device 10 for removing Ca and Mg ions from raw water and allowing to remain or adding Na ions in the raw water, tanks 20 and 30, a section for merging a fuel oil from the tank 30 and processed water from the tank 20, a section 50 for producing the emulsion fuel from a mixture of the merged fuel oil and processed water, and a section for supplying the emulsion fuel to the combustion apparatus 70.

Colloidal carbonaceous material-in-water slurries having nano-particles of carbonaceous material creating a pseudo-fluid. The colloidal carbonaceous material-in-water slurry generally includes from about fifty to about seventy two weight percent of carbonaceous material, with about 20 to about 80 percent of the carbonaceous material having a particle size of about one micron or less with a mode particle size of about 250 nanometers. The carbonaceous material-in-water slurry can also include a surfactant system containing one surfactant or mixtures of two or more surfactants, or mixtures of one or more surfactants and an inorganic or organic salt. The carbonaceous material-in-water slurry can be used in low NOx burner applications as the main fuel and/or the reburn fuel, in gasification processes as the input fuel either alone, or in combination with organic materials, in gas turbine applications, and in diesel engine applications.

A fuel emulsion for powering a diesel engine contains water, a fuel, and an emulsifier package containing a quaternary ammonium surfactant. A method for powering a diesel engine with the fuel emulsion involves preparing the fuel emulsion by emulsifying a fuel and water in the presence of the emulsifier package. An emulsifier package for emulsifying a fuel and water contains a quaternary ammonium surfactant and at least one nonionic surfactant, which is an alkoxylate. The quaternary ammonium surfactant is obtainable by reacting a quaternizable nitrogen compound containing at least one quaternizable, especially tertiary, amino group with a quaternizing agent, which converts the at least one quaternizable, especially tertiary, amino group to a quaternary ammonium group, where the quaternizing agent is a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid.

An emulsion comprising an oil phase and an aqueous phase; the emulsion comprising: from about 0.05 wt. % to about 1 wt. % of a surfactant; and from about 0.1 wt. % to about 95 wt. % of C5 carbohydrate; and/or from about 0.1 wt. % to about 95 wt. % of C6 carbohydrate; wherein the sum of the components in the emulsion does not exceed 100 wt. %.