2176.     MARKLEY, K. S., AND GOSS, W. H.  Märkische Seifen Industrie.  BIOS Final Rept. 86, 1945, pp. 25-32, PB 18,911; PB Rept. 225.

        Besides the above-named plant (raw material capacity, 40,000 tons per yr.), 3 other plants have produced synthetic fatty acids:  Oppau (capacity 20,000 tons); Heydebrech (20,000 tons); and Magdeburg (12,000 tons).  The raw material is gatsch produced in the Fischer-Tropsch process.  Material made in coal hydrogenation plants cannot be employed because it contains aromatic compounds.  About 150-200 tons of fatty acids per month was the maximum used for the production of synthetic fats and margarine.  Fatty acids C₁₀-C₁₈ (55-60% of the total fatty acids obtained) are used for edible purposes as compared with the C₈-C₂₂ acids (60-65% of the total fatty acids) used for soap making.  A flow sheet of the process and plant for the manufacture of fatty acids is attached.  The oxidation of the gatsch by air is carried out at 110° in Al vessels with stainless steel (V2A) tops and at atmospheric pressure in the presence of 0.2% KMnO₄ as catalyst.  The reaction is continued until the mixture contains about 33-35% fatty acids, the remaining nonoxidized material being recycled.  The overall yield of fatty acids is about 80%.  Synthetic fats and margarine are made from the fatty acids by esterifying with glycerin at 120°-180° in the presence of a Zn catalyst.  Whereas, the fatty acids themselves have a strong, unpleasant odor, the fats made from them are much better and have very good keeping qualities.  It also is claimed that synthetic fats are utilized in the body as well as natural fats and are more suitable for diabetics, the explanation being that while diabetics burn the even number of C chains present in natural fats to give acetone, the odd number chains in synthetic fats, in addition to even number chains, are burned to propionic acid and finally give CO₂ and H₂O.  The cost of synthetic acids in the different plants ranged RM 70-120 per 100 kg., whereas that from natural oils during the war was RM 140.  The cost, however, depends upon the price of gatsch (during the war this was RM 30 per 10 kg.), and normally synthetic acids for soap making would cost 2 times as much as natural soapmaking oils in Germany and on the world market perhaps 3 times as much.