Patent GB-499312-A (GB)
Title: A process for extracting phenolic compounds from hydrocarbon oils
IPC: C07C37/00
Filed: 1937-07-19
Abstract: <PICT:0499312/III/1> Phenols and similar compounds are obtained from mineral oil distillates by extracting with aqueous alkali metal hydroxide of 30 to 50 per cent concentration containing dissolved phenol in sufficient amount to form a single aqueous phase which is then separated from the oil layer.  The proportion of oil and alkali solution used are controlled so that in the alkali phenate solution the molar ratio of phenol to alkali metal lies between 0,8 and 0,98. The phenols are then freed from sulphur compounds by oxidation to form disulphides which are then removed by solvent extraction. Mineral oil distillates especially cracked p  distillates are distilled to obtain a fraction boiling from 175 to 300 DEG  C. which contains the bulk of the phenols.  Mineral oil distillate is fed into a fractionating tower 2 from which an overhead fraction passes to a second fractionating tower 4, and the heavy residue passes to a tank 11.  From the fractionator 4, an overhead distillate boiling below 175 DEG  C. passes through a pipe 5, and the residue passes to a tank 8.  The two phenol-containing fractions in tanks 8, 11 may be treated separately or mixed together.  These fractions are fed, together with caustic alkali from a line 17, into a mixer 13 and separator 14.  The oil layer is drawn off through a line 15, and the alkali phenate solution is divided in line 16, one part returning to the oil feed line 17, and the other passing to a tank 23.  A fresh amount of caustic soda is withdrawn from a tank 20 equal to the amount of sodium phenate solution withdrawn.  The sodium phenate solution passes to a mixer 25 together with an oxidizing agent such as hydrogen peroxide, sodium peroxide, sodium hypochlorite, ozone, or chlorine, withdrawn from a tank 27.  The mixture passes to an extractor 31, to which a solvent such as naphtha, pentane, benzol, carbon tetrachloride, or dichlorethane is admitted through a line 32. The solvent and dissolved disulphides pass out through a line 33, and the sodium phenate solution passes through a mixer 36, to which acid is admitted from a tank 37, to a separator 40.  The separated phenols are drawn off at line 41.ALSO:<PICT:0499312/IV/1> Phenols and similar compounds are obtained from mineral oil distillates by extracting with aqueous alkali metal hydroxide of 30 to 50 per cent concentration containing dissolved phenol in sufficient amount to form a single aqueous phase which is then separated from the oil layer.  The proportions of oil and alkali solution are controlled so that in the alkali phenate solution the molar ratio of phenol to alkali metal lies between 0,8 and 0,98.  The phenols are then freed from sulphur compounds by oxidation to form disulphides which are then removed by solvent extraction.  Mineral oil distillates, especially cracked distillates are distilled to obtain a fraction boiling between 175 and 300 DEG  C. which contains the bulk of the phenols.  Mineral oil distillate is fed into a fractionating tower 2 from which an overhead fraction passes to a second fractionating tower 4, and the heavy residue passes to a tank 11.  From the fractionator 4, an overhead distillate boiling below 175 DEG  C. passes through a pipe 5, and the residue passes to a tank 8.  The two phenol-containing fractions in tanks 8, 11 may be treated separately or mixed together.  These fractions are fed, together with caustic alkali from a line 17, into a mixer 13 and separator 14.  The oil layer is drawn off through a line 15, and the alkali phenate solution is divided in a line 16, one part returning to the oil feed line 17, and the other passing to a tank 23.  A fresh amount of caustic soda is withdrawn from a tank 20 equal to the amount of sodium phenate solution withdrawn.  The sodium phenate solution passes to a mixer 25 together with an oxidizing agent such as hydrogen peroxide, sodium peroxide, sodium hypochlorite, ozone, or chlorine, withdrawn from a tank 27.  The mixture passes to an extractor 31, to which a solvent such as naphtha, pentane, benzol, carbon tetra chloride, or dichlorethane, is admitted through a line 32.  The solvent and dissolved disulphides pass out through a line 33, and the sodium phenate solution passes through a mixer 36 to which acid is admitted from a tank 37, to a separator 40.  The separated phenols are drawn off at a line 41.