GB427042A - Improvements in the manufacture and production of lubricating oils - Google Patents

Abstract

Lubricating-oils are obtained by: (1) converting coal, peat, or other solid carbonaceous materials into liquid products, e.g. by extraction, low - temperature carbonization, destructive-hydrogenation, or coking, followed or not by cracking or destructive-hydrogenation; (2) topping the liquid products to 350 DEG C., and purifying the residue or fractions containing such residue at elevated temperatures by alcoholic solutions of caustic alkalies or other alkaline reagents; and (3) treating the purified products with selective solvents mixed or not with active carbon or bleaching earths. The oils may then be improved by removing paraffin wax and/or adding agents lowering the setting point. When the 350 DEG C. residues contain large proportions of asphalt or resin these impurities are preferably removed by precipitants or extraction agents, e.g. benzine, illuminating oils, and liquefied gaseous hydrocarbons, before treatment with alcoholic alkali. Selective solvents specified are phenols, liquid sulphur dioxide, liquefied gaseous hydrocarbons, aniline, acetone or other ketones, keto-acids, e.g. levulinic acid. The conversion of the coal or peat into liquid products may be effected by extraction with such solvents as benzine, benzene, middle oils, heavy oils, pyridine, or halogenated hydrocarbons, mixed or not with alcohol or ether, and advantageously under pressure and at 50--500 DEG C.; or by destructive hydrogenation at 350--600 DEG C.; the tarry product is then distilled to 300, 325, or 350 DEG C. In an example, finely ground lignite is treated with dilute sulphuric acid to neutralize basic constituents, impregnated with ammonium molybdate, made into a paste with lubricating oil, treated with hydrogen at 200 atmos. and 475 DEG C., and the mainly liquid products are distilled up to 350 DEG C. 1000 gms. of the residue is boiled under reflux with a solution of 100 gm. of caustic potash in 300 c.c. of ethyl alcohol, and allowed to stand; the refined oil is separated, washed with 5 per cent sulphuric acid, and treated 3 times with equal amounts of phenol at 50 DEG C. The product is freed from phenol by distillation, and from paraffin wax by diluting and cooling.