1495. ---------------. [HORNE, W. A., AND FARAGHER, W. F.] Interrogation of Dr. Pier and Staff. I. G. Farbenindustrie A.-G. Ludwigshafen and Oppau. IV. Oxidation Process. Fatty Acid Production. FIAT Final Rept. 426, 1945, pp. 9-11; Bureau of Mines Inf. Circ. 7,376; PB 1,367 and 7,745; TOM Reel 199.

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Literature Abstracts

Paraffin waxes produced by the hydrogenation of brown coal, from crude petroleum oils and from the Fischer-Tropsch synthesis, have been oxidized successfully to fatty acids. The molten wax is blown with air in pure Al towers in presence of Mn compounds, such as KMnO₄ or Mn soaps; 0.08-0.15% of Na or K carbonate improves the quality of the products. A temperature of 130°-160° is maintained until oxidation begins and is then lowered to 100°-120°. The lower the oxidation temperature, the smaller is the formation of peroxides, but the longer the reaction time. The airflow is continued for 10-30 hr. until approximately 30% of the paraffin is converted. The product has an acid number of 75 and a saponification number of 130-150. The oxidation product is saponified with aqueous NaOH (20-25% at 80°), heated in an autoclave to 130°-150° under pressure, the soap solution and the unsaponifiable product separating in layers, the former at the bottom. The upper layer is recycled to the oxidation tower, the lower heated in a pipe still to 280°-350° at 80-100 atm., the pressure being released flashing the water vapor and the remaining unsaponifiable material. The molten soap from the flash tower is dissolved in water and hydrolyzed with H₂SO₄. The fatty acid is washed and distilled under a vacuum of 3 mm. Based on 100 parts of paraffin the following 3 fractions are obtained: Acids C₃-C₁₀ boiling up to 150°, 7-15%; soap acids C₃-C₁₀ boiling 150°-240°, 45-55%; higher acids C₁₆-C₂₅ boiling 240°-300°, 2-5%; residue 5-20%. The plant at Oppau had a capacity of 20,000 ton of paraffin wax per yr.