Process for the removal of metals and nitrogen from hydrocarbon oils

Metallic and nitrogen-containing contaminants are removed from hydrocarbon oils, for example a crude oil, or a kerosene, gas oil, or lubricating oil fraction of petroleum, by treatment with anhydrous hydrogen fluoride, characterized in that liquid propane or n-butane containing anhydrous hydrogen fluoride in an amount not exceeding 1% wt., and in any event not more than that which will dissolve in the propane or n-butane, is contacted with the hydrocarbon oil in a ratio of from 1 to 12 volumes of liquid propane or n-butane per volume of hydrocarbon oil at a temperature within the range 0-150 DEG C. and at a pressure which maintains the hydrogen fluoride component as well as the propane or n-butane in liquid phase, and said contaminants are thus precipitated, while avoiding the formation of a dual phase liquid system, the resultant precipitate being separated from the treated oil. Pressures up to 30 atmos. are generally sufficient.