The photo is sourced from pirolizator.ru
The emulsions are mechanical mixtures of oil and stratum water, which do not dissolve in one another. There are two types of oil emulsion: the oil-in-water (O/W) emulsion means that drops of oil are suspended in water, while as the inverted emulsion (water-in-oil) means that drops of water are suspended in oil. The scientists from the Vernadsky Institute of RAS worked with the second type of emulsion, where the average diameter of water drops makes 30-45 µm (0.030 – 0.045 mm).
“We wanted to create a simple and efficient method of breaking stable water-in-oil emulsions (their intermediate layers), which would not require application of big amounts of specialised chemical agents (de-emulsifiers)”, the Ministry of Education and Science says citing the words of Tatiana Maryutina, Doctor of Chemistry, the Head of the concentration laboratory of the Vernadsky Institute.
The researchers exposed the emulsion to ultrasonic treatment with 1 KW capacity and 22±10% KHz frequency, simultaneously using the nanosized additive – the aluminium nitride suspended in acetone. This allowed for breaking the water drops’ capsules normally impeding their coalescence. The result was merging of the water drops and the emulsion separating into oil with water content not exceeding 0.5% of total mass, and water with oil content not exceeding 46 mg per litre.
Separation of the emulsion also resulted in generation of solid particles sediment (sludge) containing ferric sulphide, silicon oxide, natrium chloride, magnesium and calcium salts, as well as aluminosilicates (particles of sand and clay). This sediment is not classified as hazardous waste, so it may be used in manufacturing road coverings and tiles. Thanks to the fact that all the side impurities are concentrated in the sludge, the water extracted from the emulsion may be used in oil fields for various purposes, and the oil may be sent downstream for refining.