GB762362A - Improvements in the treatment of solutions containing carboxylic acids and derivatives thereof - Google Patents

Abstract

A C8-C24 aliphatic carboxylic acid or a lactone or an estolide of a C8-C24 hydroxy aliphatic carboxylic acid is removed from its solution in an organic solvent in which it does not ionize by contacting the solution, in the presence of water, with an anion exchange material having alkaline properties. The process is primarily concerned with purifying fatty oils from free fatty acids &c. but the latter may also be in solution in volatile solvents such as petroleum ether, carbon tetrachloride, trichlorethane and hexane. In the case of fatty oils they may be diluted with an oil-solvent. The anion exchange material is preferably an anion exchange resin of general formula <FORM:0762362/IV(b)/1> where R1 and R2 are alkyl groups such as methyl groups, R3 is an alkyl group or a hydroxy-alkyl group such as methyl or hydroxyethyl, and R4 is a polystyrene group bound by a di-vinyl benzene bridge to another quaternary ammonium group. The anion exchange material having alkaline properties may be formed by washing an anion-exchange material with an aqueous alkaline hydroxide solution until the wash liquor shows only a slight reaction for anion followed by washing with water until the wash liquor is neutral. The water necessary in the process may be present in the solution which is contacted with the anion exchange material. Alternatively the water may be present in the anion exchange material before it is contacted with the solution. The proportion of water is variable but should be insufficient to cover the surface of the exchange material as a separate phase. Refining may be effected by stirring a batch of crude or de-slurried oil with the anion-exchanger and separating the latter by filtration, or by directing a stream of oil through a column of the material. A small quantity of ammonia may be mixed with the oil before the treatment. The anion-exchange material loaded with the fatty acid &c. is regenerated by treatment with an aqueous alkaline hydroxide solution having a pH not less than 11.8. The regeneration may be effected by first exchanging the fatty acid radical by another acid radical, a salt of which other acid radical and an alkaline hydroxide is soluble in an aqueous alkaline hydroxide solution, and then treating the anion exchange material loaded with the other radical with an alkaline hydroxide solution having a pH not less than 11.8. The Provisional Specification refers to the removal of coumarin from its solution in an organic solvent.ALSO:A C8-C24 aliphatic carboxylic acid or a lactone or an estolide of a C8-C24 hydroxy aliphatic caboxylic acid is removed from its solution in an organic solvent in which it does not ionise by contacting the solution, in the presence of water, with an anion exchange material having alkaline properties. The process is primarily concerned with purifying fatty oils from free fatty acids &c., but the latter may also be in solution in volatile solvents such as petroleum ether, carbon tetrachloride, trichloroethane and hexane. In the case of fatty oils they may be diluted with an oil-solvent. The anion exchange material is preferably an anion exchange resin of general formula <FORM:0762362/III/1> where R1 and R2 are alkyl groups such as methyl groups, R3 is an alkyl group or a hydroxy-alkyl group such as methyl or hydroxyethyl, and R4 is a polystyrene group bound by a de-vinyl benzene bridge to another quaternary ammonium group. The anion exchange material having alkaline properties may be formed by washing an anion-exchange material with an aqueous alkaline hydroxide solution until the wash liquor shows only a slight reaction for anion followed by washing with water until the wash liquor is neutral. The water necessary in the process may be present in the solution which is contacted with the anion exchange material. Alternatively the water may be present in the anion exchange material before it is contacted with the solution. The proportion of water is variable but should be insufficient to cover the surface of the exchange material as a separate phase. Refining may be effected by stirring a batch of crude or de-slimed oil with the anion-exchanger and separating the latter by filtration, or by directing a stream of oil through a column of the material. A small quantity of ammonia may be mixed with the oil before the treatment. The anion exchange material loaded with the fatty acid &c. is regenerated by treatment with an aqueous alkaline hydroxide solution having a pH not less than 11.8. This regeneration may be effected by first exchanging the fatty acid radical by another acid radical, a salt of which other acid radical and an alkaline hydroxide is soluble in an aqueous alkaline hydroxide solution, and then treating the anion exchange material loaded with the other radical with an alkaline hydroxide solution having a pH not less than 11.8. The Provisional Specification refers to the removal of coumarin from its solution in an organic solvent.