GB466980A - Processes for refining hydrocarbon oils - Google Patents

Abstract

Hydrocarbon oils are refined by countercurrent or batch treatment with one or more of the following solvents: allylamine, phenylnaphthylamine, diphenyl-ethylene diamine, benzyl-aniline, propionamide, p-amido-diphenyl, allyl cyanide, m-nitro-benzaldehyde, p-nitrodiphenyl ether, o-nitro-diphenyl, quinoline, butyramide, o-nitraniline, o-anisidine. The selective solvents may be mixed with auxiliary solvents of the following types: (A) those soluble preferably in the selective solvent and also soluble in the oil treated; examples are aromatic and hydroaromatic hydrocarbons (other than polycyclic aromatic hydrocarbons) and non-selective aliphatic and aromatic halogen derivatives such as chlorinated hydrocarbons; they increase the solvent power and so the amount of extract, leaving a more refined oil; (B) those miscible with the selective solvent but not or only slightly with the oil; examples are alcohols and organic acids; they decrease the solvent power and so the amount of extract, which is desirable when treating naphthene-base oils; (C) those miscible with the oil only; examples are propane, butane, or other low-boiling paraffins; they sharpen the selective power. Dewaxing, before or after extraction, may be effected by chilling and centrifuging, filtering, or decanting, using as diluent a mixture of such proportions of selective solvent and auxiliary solvent of type A or C that the solvents do not separate from each other on chilling. The slack wax may be refined by treatment with the same or a different solvent mixture. Recovery of the solvents from the raffinate, extract, wax, or dewaxed oil is effected by distillation or by extraction with solvents not dissolving the oils or wax. In examples, a dewaxed oil is batch-extracted at 40 DEG F. with 1, 0,5, and 0,5 vol. respectively of quinoline or a blend of 80 litres of quinoline with 20 litres of ethyl alcohol.