GB466978A - Processes for refining hydrocarbon oils - Google Patents

Abstract

In the selective extraction or dewaxing of hydrocarbon oils, the oils are treated with one or more of the following solvents, acetonylacetone, dipropyl ketone, acetyl acetone, acetophenone, diacetyl, benzal acetone, fluorenone, benzene sulphonic acid, benzoic anhydride, ethylene oxide, allyl alcohol, phenyl propyl alcohol, resorcinol mono- or di-methyl ether, thioacetic acid, propylene oxide or methyl propyl ketones. These solvents extract the nonparaffinic constituents from the mineral oils. Mineral oil distillates, low temperature or brown coal tar oils may be treated. The extraction may be effected in a batch or countercurrent process, and the selective solvents may be mixed with auxiliary solvents such as (a) aromatic, or hydroaromatic hydrocarbons, nonselective halogenated hydrocarbons, or nonselective ketones, esters, ethers e.g. diethyl ether, ethyl acetate or methyl ethyl ketone, (b) alcohols, or organic acids which decrease the selective power of the selective solvent, and (c) low-boiling paraffinic hydrocarbons e.g. propane and butane. The oil raffinate may be further treated with clay at 450 DEG F. Mineral oils may be dewaxed with a mixture of one of the selective solvents which are poor solvents for wax with auxiliary solvents of classes (a) or (c), and may be effected prior to or after extraction. The wax is separated from the chilled solution by decanting, filtering or centrifuging. The slack wax containing some oil may be further treated with the solvent mixture to produce petrolatum. Solvents are recovered from the dewaxed oils and the oil extracts by distillation or by extracting the solvent by washing with another solvent. The resulting mixture of solvents is then distilled or treated with water or other agents providing separation. Specifications 466,977, 466,979, and 466,980 are referred to.