Patent GB-661364-A (GB)
Title: Improvements in and relating to the production of alkyl sulphates and detergents obtained therefrom
IPC: C07C303/24
Filed: 1947-06-30
Abstract: Alkyl hydrogen sulphates and/or dialkyl sulphates suitable for conversion into detergents, are prepared by subjecting a monoolefine containing liquid feed-stock obtained by the distillation of shale to extraction with an inert non-aqueous polar solvent for the removal or partial removal of nitrogen bases, phenols and components such as dienes which are more reactive than the mono-olefines, recovering a mono-olefine containing raffinate and contacting said raffinate with sulphuric acid to produce the alkyl sulphates in known manner, the term "known" being used to designate a method in actual use or described in the literature on the subject.  The preferred liquid feed-stock is a shale spirit fraction boiling in the range 180 DEG to 340 DEG  C.  Inert polar solvents mentioned are liquid sulphur dioxide, furfural, phenol, aniline and dimethyl sulphate.  Sulphur dioxide is the preferred solvent and is usually employed at - 20 DEG to - 30 DEG  C. in an amount constituting 75 to 500 per cent by volume of the feed-stock treated.  The normally liquid solvents may be used at a temperature of 45 DEG  to 100 DEG  C.  Batchwise or continuous solvent extraction methods may be used.  The raffinate is weathered and separated from the solvent and then sulphated.  The selective solvents may be recovered by distillation, phenol; aniline and furfural may be recovered by washing with alkali, acid and water. The alkyl sulphates are of improved colour and odour as compared with the products obtained from a feed-stock which has merely been subjected to acid and alkali washings.  In examples: (1) a shale oil fraction boiling in the range 190 DEG  to 320 DEG  C. is agitated at - 10 DEG  C. with 75 per cent of its volume of liquid sulphur dioxide, the raffinate separated, twice again extracted in this manner and the final raffinate stripped of sulphur dioxide and sulphated with 98 per cent sulphuric acid at 10 DEG  C.; the product is allowed to settle and the upper layer treated with excess aqueous sodium carbonate forming a detergent solution of sodium alkyl sulphates; (2) as in (1) above, but extracting the feed-stock three times with an equal volume of liquid sulphur dioxide.  The nitrogen and sulphur contents of the raffinate, the acid consumption in the sulphation and the yield are compared with a similar raffinate from the same feed-stock only subjected to acid and alkali washings. Specification 657,598 is referred to.  According to the Provisional Specification the process may be applied to any olefine-containing feed-stock.ALSO:Mono-olefine containing liquid feed-stocks obtained by the distillation of shale are subjected to extraction with an inert non-aqueous polar solvent for the removal or partial removal of nitrogen bases, phenols, and components such as dienes, which are more reactive than the mono-olefines, and a mono-olefine containing raffinate recovered.  The raffinate is utilised in the production of alkyl sulphates (See Group IVb).  The preferred feed-stock is a shale spirit fraction boiling in the range 180 DEG  to 340 DEG C.  The selective extraction may be carried out batchwise, if desired in multi-stage operation, or continuously.  The preferred polar solvent is liquid sulphur dioxide which is normally employed at a temperature of - 20 DEG  to - 30 DEG C. and in an amount constituting 75 to 500 per cent by volume of the feed-stock.  Other solvents mentioned are phenol, furfural, aniline and dimethyl sulphate which may be used at a temperature of 45 DEG  to 100 DEG C.  The recovered raffinate is weathered and separated from the solvent, e.g., by distillation; when the solvent is phenol, aniline or furfural, it may be recovered by washing with alkali, acid or water.  In Examples, a shale oil fraction boiling in the range 190 DEG -320 DEG C. is agitated at -10 DEG C. with 75 or 100 per cent of its volume of liquid sulphur dioxide three times and the final raffinate is weathered and heated in a steam bath under reduced pressure until free of sulphur dioxide. The nitrogen and sulphur contents of the raffinate are compared with those of the same feed-stock which has been washed with 25 per cent sulphuric acid and then with 10 per cent caustic soda.  Specification 657,598, [Group IV (b)], is referred to.  According to the Provisional Specification the process may be applied to any olefine-containing feed-stock.