Patent GB-206535-A (GB)
Title: Improvements in the purification of oils, waxes and the like
IPC: C10G73/42
Filed: 1922-05-04
Abstract: Carbon tetrachloride and benzene are purified by filtration through bauxite or ignited magnesite using a brade of purifier best suited for the treatment of the particular substance, the selection being based on the following considerations:-(1) the dielectric constant or permittivity of the impurity must be greater than that of the substance before its removal is possible; (2) where bodies are present that have permittivities higher than that of the substance but lower than that of the impurity, the grade of bauxite must be so low that it is "commercially" inert to these substances.  The Specification refers to the removal of benzene from petrol by agitation with nitric acid and removal of the nitrobenzene by bauxite.  Specifications 16617/08, [Class 46, Filtering &c.], and 149,453, [Class 1 (iii), Oxides &c., Metallic], are referred to.ALSO:In the purification of oils, waxes, &c. by filtration through bauxite or ignited magnesite a grade of purifier best suited for the treatment of the particular oil &c. is used, the selection being based on the following considerations:-(1) the dieletric constant or permittivity of the impurity must be greater than that of the oil before its removal is possible; (2) where substances are present that have permittivities higher than that of the oil but lower than that of the impurity, and it is desired to retain them, e.g. olefines or naphthenes in an oil of paraffin base containing sulphur, the grade of bauxite must be so low that is is "commercially" inert to these substances.  For example, in desulphurizing a mineral oil, the olefine content is estimated by a bromine absorption test, the sulphur content is estimated by determining the sulphuric acid produced by burning the oil, the permittivity of the oil is deduced from the initial and final boiling points of the oil and of the known permittivities of pentanes, kerosenes, and lubricating oils, and the permittivity of the sulphur bodies by comparison of the action of different grades of bauxite on the oil and on a refined similar oil to which are added different proportions of substances of high and known permittivity such as methyl alcohol or nitrobenzene.  If necessary the permittivity of the impurity is then made greater than that of the oil by either (1) modifying the impurity as by treatment with sulphuric acid, nitric acid, sodium hydrate, chlorine, or chlorine oxides; or (2) diluting the oil with a liquid of low permittivity such as petrol.  If olefines are absent the highest grade of bauxite is then used.  If olefines are present, a grade slightly higher than that indicated by the ratio of the permittivities is taken and steadily degraded and tested at different temperatures until the most efficient grade and temperature are found.  The bauxite is degraded by adding ferric oxide, ferrous sulphate, caustic soda, or salts of the alkalies, copper, nickel, manganese, or of other metal, and igniting.  It may be up-graded by adding aluminium nitrate and igniting.  The Specification refers to the removal of benzol from petrol by agitation with nitric acid and removal of the nitrobenzene by bauxite, the sulphonation or alkali treatment of other impurities such as colouring matters in petrol, kerosene, paraffin or other wax, and vegetable oils followed by filtration through bauxite, and of the desulphurization of mineral oil by passing air charged with chlorine or oxides of chlorine through the oil before filtration through bauxite.  Specifications 16617/08 and 149,453 are referred to.ALSO:Carbon bisulphide, carbon tetrachloride, &c., are purified by filtration through bauxite or ignited magnesite using a grade of purifier best suited for the treatment of the particular substance, the selection being based on the following considerations:-(1) the dielectric constant or permittivity of the impurity must be greater than that of the oil before its removal is possible; (2) where substances are present that have permittivities higher than that of the oil but lower than that of the impurity, and it is desired to retain them, e.g. olefines or naphthenes in an oil of paraffin base containing sulphur, the grade of bauxite must be so low that it is "commercially" inert to these substances.  For example, in desulphurizing a mineral oil, the olefine content is estimated by a bromine absorption test, the sulphur content is estimated by determining the sulphuric acid produced by burning the oil, the permittivity of the oil is deduced from the initial and final boiling points of the oil and of the known permittivities of pentanes, kerosenes, and lubricating oils, and the permittivity of the sulphur bodies by comparison of the action of different grades of bauxite on the oil and on a refined similar oil to which are added different proportions of substances of high and known permittivity such as methyl alcohol or nitrobenzene.  If necessary the permittivity of the impurity is then made greater than that of the oil by either (1) modifying the impurity as by treatment with sulphuric acid, nitric acid, sodium hydrate, chlorine, or chlorine oxides, or (2) diluting the oil with a liquid of low permittivity such as petrol. If olefines are absent the highest grade of bauxite is then used. If olefines are present, a grade slightly higher than that indicated by the ratio of the permittivities is taken and steadily degraded and tested at different temperatures until the most efficient grade and temperature are found.  The bauxite is degraded by adding ferric oxide, ferrous sulphate, caustic soda, or salts of the alkalies, copper, nickel, manganese, or of other metal and igniting.  It may be upgraded by adding aluminium nitrate and igniting.  The Specification refers to the removal of benzol from petrol by agitation with nitric acid and removal of the nitrobenzene by bauxite, the sulphonation or alkali treatment of other impurities such as coloring matters in petrol, kerosene, paraffin or other wax, and vegetable oils followed by filtration through bauxite, and of the desulphurization of mineral oil by passing air charged with chlorine or oxides of chlorine through the oil before filtration through bauxite.  Specifications 16617/08 and 149,453 [both in Class 46, Filtering &c.], are referred to.