Kurita provides tailored treatment concepts for refinery applications

Emulsion breakers improve oil/water phase separation.

Crude oil or slop oils often contain very stable emulsions, which are fine dispersions of oil and water. Emulsions can cause severe fouling and corrosion problems in distillation columns, heat exchangers and reboilers. In general, the emulsion is stabilized by a variety of contaminants and additives from upstream operations. Common stabilising components for an unwanted emulsification are asphaltenes, resins, porphyrins, wax crystals or fatty acids. Such components may react as surfactants with a drop size in the micron range.

Pumped crude oil from the well contains water in emulsified and free state. Untreated crude oil still comprises water and salts when stored in tank farms. The crude oil emulsion consists of small globules of water surrounded by the oil. Crude oil separation to remove oil from water is a very important application step. The emulsion breaking performance is influenced by the composition of the emulsion phase and contaminants. Reduction of impurities and salts from the crude oil are directly related to less corrosion and fouling.  This will improve the desalting efficiency, oil recovery and crude oil separation performance. The bigger droplets will finally settle down to be removed as desalter effluent water. Many crude oils contain a high concentration of solids (BS&W = Basics, Sediments & Water). Such crude oils are difficult to process. Negative impacts are electrical desalter upsets, fouling and corrosion of the downstream distillation equipment.

An adequate residence time is essential for the crude oil separation to remove oil from water. Crude oil separation into two phases by gravity is a very slow process. The physical process can be accelerated by using a suitable chemical emulsion breaker programme. The additives used are termed demulsifiers, emulsion breakers or wetting agents. These chemicals are surfactants, which migrate to the oil/water interface. Nonionic surfactants having both of lipophilic and hydrophilic groups are mainly used. They break the crude oil emulsions that water droplets aggregate to form bigger water drops. That drops are large enough to gravitationally separate them from the oil.

By adding Kurita´s emulsion breaker chemicals you will already achieve far better results. Excellent oil recovery of slop oils and a better dewatering and desalting of crude oils are important measures. The use of the emulsion breaker reduces the risk of corrosion and fouling in the downstream refining operations. Our high-performing programmes accelerate the crude oil separation. This improves the emulsion breaking process to remove oil from water. The risk of undesired oil carry-over into the desalter effluent water will be minimised. The desalted crude oil contains less water and fewer salts with a lower risk of corrosion and fouling. A very good desalting efficiency with increased oil recovery is the key element for the slop oil or desalter treatment. Your benefits are a higher profitability with increased utilisation of the downstream equipment.

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