3691.     ---------------.  [WIETZEL, G.]  [Synthesis of Fatty Acids by Oxidation of Hydrocarbons.]  Angew. Chem., vol. 51, 1938, pp. 531-537; Brennstoff-Chem., vol. 20, 1939, p. 130; Chem. Age., vol. 39, 1938, p. 278-280; Chem. Abs., vol. 33, 1939, p. 420.

        General discussion with graphs and figures.  The oxidation of synthetic paraffin from the Fischer-Tropsch process is carried out with air at temperatures of 80-120, under pressure and with catalysts.  Overoxidation should be avoided by careful control of the temperature and the time of operation.  The choice of catalysts is important also, since they may promote the oxidation at lower temperatures and prevent overoxidation.  Oxidation takes place after the material has been suitably prepared, therefore, by saponification with caustic and separation of the unsaponified constituents either by selective solution or by distillation at 300-400.  This treatment also clarifies and deodorizes the saponified portion of the fatty acids.  The unsaponified portion is mixed with fresh paraffin and recycled.  The crude soap does not yet meet the requirements for use but must be split by means of mineral acids into fatty acids and be subjected to vacuum distillation, whereby about 50-80% of the original raw material is preserved in a form pure enough for soapmaking.  Some remarks are made also on the food fats made from synthetic fatty acids by esterifying with glycerin.  The results thus far obtained have some appearance of success even though the work has not yet gone beyond the experimental stage.