874.    ---------------.  [FARAGHER, W. F. AND HORNE, W. A., HOWES, D. A., SCHINDLER, H., CHAFFEE, C. C., WEST, H. L., AND ROSENFELD, L.]  Supplemental Report on Ruhrchemie A. G., Sterkrade-Holten, Ruhr.  Synthetic Lubricating Oil Manufacture.  CIOS Rept. XXXII-96, 1945, pp. 5-13; TOM Reel 196; PB 1366.

                 Raw material for the manufacture of synthetic lubricating oil by the Ruhrchemie process consists of olefins in the gasoline boiling range having 1 double bond at the end of the chain that are obtained by cracking Fischer-Tropsch gas oil and sweet oil from Fischer-Tropsch wax.  Gas oil from plants operating at atmospheric pressure or at 10-15 atm. is suitable.  The gas oil has a boiling range of about 230-320.  The feed stock, thus obtained, and containing not more than 0.015% of H2O, is polymerized in the presence of 1.2-1.5% of AlCl3, the temperature being gradually raised from 40 to 100 over a period of 4-6 hr.  The synthetic oil product is separated from the catalyst-complex oil by setting; dechlorinated by treatment with 1.5% each of Tonsil, HCl activated clay, and ZnO at 180 for 3 hr.; and double distilled, yielding about 33% gasoline, naphtha diesel oil and spindle oil and 64% lubricating oil, 3% being lost.  The finished motor oil has a density at 20 of 0.855, viscosity at 50 7E and pole height 1.75.  Owing to the unsaturated character of the synthetic oil, it was very unstable toward oxidation and only a temporary improvement was obtained by subjecting it to a second treatment with 1% AlCl3 at 180 for 3 hr.  A more permanent improvement was obtained by adding 0.2-0.5% by weight of phenthiazin to the olefins before polymerization.  Another method was to add 0.3-0.5% by weight of S to the feed stock before polymerization and then treating the oil with 1% by weight of AlCl3 at 250 for 5 hr.  The viscosity of the finished oil could be changed by changing the conditions of polymerization.  Using 1.5% by weight of AlCl3 and keeping the temperature at 100 from the start of the reaction gave an oil low viscosity, 4 E at 50, whereas when 4-6% AlCl3 is used and the temperature kept at 15 for 12-20 hr. followed by heating to 60 for 2 hr., an oil of 38 E at 50 is obtained.  The viscosity index and resistance to oxidation were also improved by using olefins with longer chains.  In making aviation grade bright stock by the so-called Synthol process, a different feed stock had to be used; only olefins from C9 to C18 were to be used and these supplemented with C6 to C10 olefins obtained directly by the Recycle process and by the C15 to C18 paraffins, which remain unreacted in the Oxo process.  The Recycle process, designed for the manufacture of olefins, consists in using 1 vol. of water gas containing 87% of CO and H2 (CO : H2 = 1 : 1.23-1.25) with 3 vol. of recycle gas from the synthesis so that the CO : H2 = 1 : 0.8.  The catalyst is 100 Co. 15 MgO, 200 kieselguhr, the temp. of the synthesis 200-220, pressure 10-15 atm., the space velocity 800 m.3 gas per 10 m.3 catalyst per hr.  The total yield of liquid products and gasol amounts to 160 gm. per m.3 of ideal gas.  The polymerization procedure varied somewhat from that followed in the manufacture of motor lubricant; it was planned to use 4-6% by weight of AlCl3, react the olefins for 10 hr. with the catalyst at 15 and then heat for 2 hr. at 60.  Phentiazen was to be added to the olefins before polymerization.  A flowsheet shows the complete process.