Patent GB-358278-A (GB)
Title: Improvements in the recovery of fatty acids from the oxidation products of hydrocarbons
IPC: C07C51/42
Filed: 1930-10-07
Abstract: Fatty acids are isolated from the oxidation products of difficulty volatile non-aromatic hydrocarbons by introducing into the crude product at elevated temperature such as 150-300 DEG  C. and reduced pressure such as 10-50 mm. a mist of finely divided inert liquid preferably of boiling point below 105 DEG  C. such as water, benzine, benzene trichlorethylene or ethyl alcohol, if desired in an inert gaseous carrier.  The hydroxy acids and their inner esters remain behind, the pure fatty acid being distilled off. Preferably a continuously operating apparatus such as that described in Specification 277,085, [Class 32, Distilling &c.], is employed, the liquid being introduced through suitable nozzles as described in Specification 313,254, [Class 32, Distilling &c.], or by means of carrier gases or vapours such as carbon dioxide, nitrogen, or superheated steam.  A suitable suspension of liquid particles is wet steam.  Inert liquids of high boiling point such as paraffin oil, soft paraffin wax, or residues from a previous distillation may be added to the crude product to be distilled. In examples (1) fatty acids from the air oxidation of paraffin wax and subsequent extraction as described in Specification 324,538, [Class 2 (iii), Dyes &c.], is treated at 280 DEG  C. with saturated steam carrying water mist at 55 DEG  C., the pressure being 28 mm.; (2) the product of air-oxidation of Russian gas oil (containing 16,5 per cent of hydroxycarboxylic acids) is treated at 260 DEG  C. and 20 mm. with a mist of trichlorethylene obtained by passing carbon dioxide at 30 DEG C. through a chamber filled with trichlorethylene; a crude mixture of acids from "distillate oil" of paraffin wax oxidation (i.e. constituents of relatively low molecular weight distilling over during the air-oxidation at 140-160 DEG  C.) of mean molecular weight 160 is treated at 240-250 DEG  C. and 18 mm. with saturated steam carrying water-mist at 57 DEG  C.; (4) a fatty acid mixture obtained by distilling the acids for air-oxidation of hard paraffin wax is mixed with 20 per cent of the distillation residue obtained in the first example, and then treated by a process of that example.ALSO:Fatty acids are isolated from the oxidation products of difficultly volatile non-aromatic hydrocarbon by introducing into the crude product at elevated temperature such as 150-300 DEG  C. and reduced pressure such as 10-50 mm. a mist of finely divided inert liquid preferably of boiling point below 105 DEG  C. such as water, benzine, benzene, trichlorethylene or ethyl alcohol, if desired in an inert gaseous carrier.  The hydroxy acids and their inner esters remain behind, the pure fatty acid being distilled off. Preferably a continuously operating apparatus such as that described in Specification 277,085, [Class 32, Distilling &c.], is employed, the liquid being introduced through suitable nozzles as described in Specification 313,254, [Class 32, Distilling &c.], or by means of carrier gases or vapours such as carbon dioxide, nitrogen, or superheated steam.  A suitable suspension of liquid particles is wet steam.  Inert liquids of high boiling-point such as paraffin oil, soft paraffin wax, or residues from a previous distillation may be added to the crude product to be distilled. In examples, (1) fatty acids from the air oxidation of paraffin wax and subsequent extraction as described in Specification 324,538, [Class 2 (iii), Dyes &c.], is treated at 280 DEG  C. with saturated steam carrying water mist at 55 DEG  C., the pressure being 28 mm.; (2) the product of air-oxidation of Russian gas oil (containing 16,5 per cent of hydroxycarboxylic acids) is treated at 260 DEG  C. and 20 mm. with a mist of trichlorethylene obtained by passing carbon dioxide at 30 DEG C. through a chamber filled with trichlorethylene; a crude mixture of acids from "distillate oil" of paraffin wax oxidation (i.e., constituents of relatively low molecular weight distilling over during the airoxidation at 140-160 DEG  C.) of mean molecular weight 160 is treated at 240-250 DEG  C. and 18 mm. with saturated steam carrying water-mist at 57 DEG  C.; (4) a fatty acid mixture obtained by distilling the acids from air-oxidation of hard paraffin wax is mixed with 20 per cent of the distillation residue obtained in the first Example, and then treated by the process of that Example.