GB442429A - Process for the separation from oil of wax or other matter which is precipitated upon cooling the oil - Google Patents

Abstract

In a process for separating wax, asphalt and similar impurities from oils, the impurity is precipitated in the oil and the resulting mixture is submitted to an electric field, and finally the coagulated impurities are separated from the oil. Crude lubricating oil passes from a tank 10 to a chiller 20 where it is mixed with a light hydrocarbon diluent and shock-chilled to precipitate the wax in the oil. The mixture is then pumped into a chamber 25 provided with a high voltage electrode 27, the container forming the second electrode. The wax is precipitated and removed through a pipe 34, and the upper layer of oil containing some wax is pumped into a tank 50 in which the remainder of the wax settles, and the waxfree oil is then freed from solvent in a still 60. The dewaxed oil is drawn off into a tank 65, and the solvent vapours are condensed and returned to a tank 11. If desired, the wax precipitate and some oil is drawn off <PICT:0442429/III/1> through the pipe 34 and passed directly to the filter press 47, or forced into the chamber 50 for further settling, the supernatant oil containing some wax being treated in a centrifuge or the filter press 47, and the filtrate is then distilled. A battery of electrical treating chambers 25 may be used and provided with scrapers for removing the wax. Potentials of 5000 to 35,000 volts per inch either continuous, interrupted direct, or alternating current are suitable. Diluents specified are naphtha, gasoline, propane, acetone, benzol, methyl chloride, di- or monochlordifluor methane, tri-or dichlorethylene, ethers or mixtures of ethers and alcohols. The impurities which are removed include asphaltines, petrolatum, and sludge.