GB240803A - An improved manufacture of petrolatum and petrolatum oils - Google Patents

Abstract

Highly purified petrolatum and petrolatum oils are obtained by heating the crude products with fuming sulphuric acid until the impurities are converted into undissolved solid or semi-solid carbonaceous matter, and dissolving the purified petrolatum &c. from the mass. In an example, 1000 kilograms of crude hydrocarbon grease are heated to 120-180 DEG C. for 24-48 hrs. with 1500 kilograms of 20 per cent oleum, and then extracted with naphtha or benzol. The solution is treated with alkali to remove acidity, and is distilled to remove the solvent. The carbonaceous matter is pulverized and calcined at a dull red heat to produce a decolorizing carbon. Any sulphur dioxide evolved is absorbed in alkali to produce sulphite. According to the Specification as open to inspection under Sect. 91 (3) (a), petroleum residues and heavy oils are purified by treatment with strong sulphuric acid at an elevated temperature. Preferably the material is first treated below 100 DEG C., and then at over 200 DEG C., e.g. 160-170 DEG C., sulphur trioxide is added to the acid, a hydrocarbon that is liquid at the temperature employed and unacted upon by the acid is mixed with the crude material, and the product is neutralized by treatment with calcium carbonate and filtration through porous clay. Oil that has been treated once with acid as above may be freed from sulphonated compound by extraction with alcohols, light naphtha, or other solvent of the pure oil, or by further treatment with 20 per cent oleum. In an example black cylinder oil is mixed with an equal weight of petroleum jelly that has already been treated with acid, and agitated with 1.5 parts by weight of 20 per cent oleum at 120-160 DEG C. for 24 hours. The liquid is drawn off, neutralized by agitation at 120 DEG C. for 3-4 hours with 10 per cent of porous clay and 1.5 per cent of calcium carbonate, and filtered hot through porous clay. The carbonaceous residue in the acid-treatment vessel is broken up and treated with naphtha, benzol, tetrachlorethylene, or other solvent of the purified oil. The solution is withdrawn, the solvent distilled off, and the oil neutralized and filtered. Alternatively the solution is chilled and the precipitated oil or jelly allowed to settle out. The carbonaceous residue is afterwards heated to about 400 DEG C. to Q remove volatile impurities, ground in a ball mill, and maintained red hot in contact with air until about half is consumed. A highly adsorbent carbon results. Sulphur dioxide evolved during the operations is absorbed in a 28 per cent solution of sodium carbonate. The porous clay is revivified in known manner after treatment at about 50 DEG C. with naptha or other solvent of the oil. This subject-matter does not appear in the Specification as accepted.