Patent GB-823237-A (GB)
Title: Process for refining hydrocarbon oils and obtaining purified surface-active products from refined oil and from acid sludges
IPC: C07C303/46
Filed: 1956-03-29
Abstract: A process for refining hydrocarbon oils comprises treating the oil with a sulphonating reagent in order to convert the impurities into sulphonic acids, separating the oil phase from the excess of sulphonating reagent, and extracting the oil phase with an oil-insoluble solvent whose minimum boiling-point at atmospheric pressure is 100 DEG  C.  The hydrocarbon oils may be mineral or synthetic, and include spindle oils, oily residues obtained from the refining by mineral oils by solvents, and used lubricating oils, transformer oils or turbine oils.  The preferred sulphonating agent is a blend of equal weights of 66 DEG  Baume sulphuric acid and of oleum containing 20% free SO3. Several treatments with the sulphonating reagent may be employed. Oil-insoluble solvents mentioned are amino-alcohols (e.g. ethanolamines and propanolamines, and especially triethanolamine), polyalcohols (e.g. glycerol, ethanediol or diethylene glycol), esters of fatty acids (e.g. glycerides), hydroxy fatty acids (e.g. ricinoleic acid), sulphonic acids (e.g. sulpho-oleic or sulpho-ricinoleic acid) and polyamines (e.g. diethylenetriamine and ethylenediamine).  If desired, the oil phase, before extraction with the oil-insoluble solvent, may be neutralized with a hydroxide or carbonate of an alkali or alkaline earth metal and filtered.  The subsequent extraction with the oil-insoluble solvent then removes the metal sulphonates.  The purified oil may finally be decolorized with activated bleaching earth and filtered.  In examples: (a) spindle oil, residue from the refining of petroleum oils by extraction with liquid SO2 or phenol, shale oil, benzol, gas oil, or oils obtained by the distillation of lignite, are sulphonated with the preferred sulphonating agent mentioned above and the oil phase is then extracted with triethanolamine; (b) used motor lubricating oil is sulphonated first with 66 DEG  Baum<\>ae sulphuric acid and then with the preferred sulphonating agent, and the oil phase is then extracted with triethanolamine; (c) used transformer oil is sulphonated as in (b) and then extracted with mono- or di-ethanolamine or mono- or tri-isopropanolamine, and (d) spindle oil is sulphonated with the preferred sulphonating agent, and the oil phase is neutralized with sodium carbonate and then extracted with triethanolamine.ALSO:A process for the production of sulphonic acids or sulphonates comprises treating a hydrocarbon oil with a sulphonating reagent in order to convert the impurities in the oil into sulphonic acids, separating the oil phase from the acid phase and subjecting each of these phases to a solvent extraction with a non-volatile solvent in order to remove the sulphonic acids or sulphonates, an oil-insoluble solvent being employed in the case of the oil phase. The non-volatile solvents have a minimum boiling point at atmospheric pressure of 100 DEG  C.  The hydrocarbon oils may be mineral or synthetic, and include spindle oils, oily residues obtained from the refining of mineral oils by solvents, used lubricating oils, transformer oils or turbine oils, alkyl benzenes and alkyl naphthalenes.  The preferred sulphonating reagent is a blend of equal weights of 66 DEG  Beaum<\>e sulphuric acid and of oleum containing 20% free SO3.  Several treatments with the sulphonating reagent may be employed.  Specified oil-insoluble solvents for extracting the oil phase are amino-alcohols (e.g. ethanolamines and propanolamines, and especially triethanolamine), polyalcohols, (e.g. glycerol, ethane diol or diethylene glycol), esters of fatty acids (e.g. glycerides), hydroxy fatty acids (e.g. ricinoleic acid), sulphonic acids (e.g. sulpho-oleic or sulpho-ricinoleic acid), and polyamines (e.g. ethylene diamine and diethylene triamine).  Where the solvent is basic, it will neutralize the sulphonic acids, so that the material extracted will be the corresponding sulphonate.  But, if desired, the oil phase, before extraction with the oil-insoluble solvent, may be neutralized with a hydroxide or carbonate of an alkali or alkaline earth metal, and the subsequent extraction then removes the metal sulphonates.  Specified solvents for extracting the acid phase are amido-alcohols obtained by condensation of fatty or naphthenic acids or tall oil with amino-alcohols (e.g. the condensation products of tall oil with mono- or di-ethanolamine or monoisopropanolamine), the soaps, esters or amides of fatty or naphthenic acids or tall oil (e.g. the mono- or di-esters of triethanolamine), fatty or naphthenic acids or tall oil themselves, polyethylene glycols or polypropylene glycols of molecular weight 300-600 or condensation products of these polyglycols (e.g. with fatty acids, fatty alcohols, alkyl phenols, sulpho fatty acids or sulpho hydroxy fatty acids), or mixtures of these.  If desired, the solvent may be employed in admixture with a light mineral oil such as spindle oil.  Some sulphonation of the solvent may occur when it is a fatty acid or tall oil.  But, before extraction, the acid phase may be water-washed to remove sulphuric acid.  Alternatively, the acid phase, before extraction, may be partially or completely neutralized with a hydroxide or carbonate of an alkali or alkaline earth metal or with ammonia.