GB920842A - Production of surface active materials - Google Patents

Abstract

Lubricating oils contain salts of acidic surface-active materials prepared by separating a heavy petroleum oil into a less-polar fraction and a more-polar fraction, and oxidizing the more-polar fraction by contact with free oxygen. The salts may be formed from organic or inorganic bases, e.g. alkaline earth hydroxides. The surface-active material may be isolated from the oxidized more-polar fraction by adsorption, e.g. on magnesium oxide, the adsorbent subsequently being washed, e.g. with benzene or acetone, dissolved in an acid, e.g. hydrochloric or acetic acid, and the material separated in a solvent, e.g. benzene, n-heptane, chloroform or petroleum ether, and recovered by distillation of the solvent. In examples refined lubricating oils and furfural extracts are contacted with silica gel, the more-polar fractions are eluted with n-heptane, isopropyl alcohol and ethyl alcohol and oxidized with air at 120 DEG C., and the surface-active material isolated by adsorption on magnesium oxide. Specifications 806,915 and 808,130 are referred to.ALSO:Surface active materials are prepared by separating a heavy petroleum oil into a lesspolar fraction and a more-polar fraction, and oxidizing the more-polar fraction by contact with free oxygen. The heavy petroleum oil may be a distillate fraction p from the vacuum distillation of crude oil, a de-asphalted vacuum residue, a lubricating oil obtained by solvent refining, de-waxing, clay treating or hydrofinishing either of these materials, or a solvent extract obtained from any of these materials using a solvent which preferentially extracts aromatics, e.g. furfural. The separation into less- and more-polar fractions may be effected (1) by contacting the heavy oil with a selective adsorbent, e.g. silica gel, magnesium oxide or alumina, and eluting with a non-polar solvent e.g. n-heptane, to obtain a less-polar fraction and continuing the elution to obtain a morepolar fraction either with the non-polar solvent or with a polar solvent, e.g. benzene, ethyl alcohol, or isopropyl alcohol or (2) by solvent extraction with a solvent which preferentially extracts the more-polar constituents, e.g. with furfural or phenol. The oxidation is carried out by blowing air through the heated fraction, e.g. at 120 DEG to 200 DEG C. The surface active material may be isolated from the oxidized more-polar fraction by adsorption, e.g. on magnesium oxide, the adsorbent subsequently being washed, e.g. with benzene or acetone, dissolved in an acid, e.g. hydrochloric or acetic acid, and the material separated in a solvent, e.g. benzene, n-heptane, chloroform or petroleum ether, and recovered by distillation of the solvent. In examples refined lubricating oils and furfural extracts are contacted with silica gel, the more-polar fractions are eluted with n-heptane, isopropyl alcohol and ethyl alcohol and oxidized with air at 120 DEG C., and the surface active material isolated by adsorption on magnesium oxide. The surface active materials are acidic and may be reacted with bases, e.g. alkaline earth hydroxides. Specifications 806,915 and 808,130 are referred to.