3527.     UNITED STATES NAVAL TECHNICAL MISSION IN EUROPE.  Thoria-Alumina Catalyst for Isoparaffin Synthesis.  Tech. Rept., 110-45, 1945, 8 pp.; Oil Gas Jour., vol. 44, No. 37, 1946, pp. 86, 89; CIOS Rept., XXV-27; PB 289, 890.

        Digest of the report, Wartime Research on Synthetic Fuels by the Kaiser Wilhelm Institut für Kohlenforschung.  A catalyst of ThO₂-Al₂O₃ (1:4) gives the best yields of all catalysts investigated.  Higher gas velocities may be used, the tendency for alcohol formation is low but high for C deposition.  Increasing the Al₂O₃ content increases CH₄ formation, and addition of 0.5-1% K₂CO₃ raises the yield slightly.  ZnO-Al₂O₃ catalyst shows slightly lower yields but better commercial prospects.  Both catalysts are prepared by precipitation from the respective nitrate solution by means of Na₂CO₃.  For synthesizing isoparaffins, pressure of 300 atm. and temperatures of 420°-450° are best.  Yield drops rapidly below 300 atm., but, as pressures increase above this, the % of O-containing products increases until at 1,000 atm. the entire product is dimethyl ether.  Temperatures below 450° show increases of alcohol and unsaturates and a decrease in C deposition.  Above 450°, the reaction rate increases rapidly with mainly naphthenic products and excessive C deposition.  The best synthesis gas is CO:H₂=1.2:1 and the best gas velocity 10 l. per hr. per 20 cc. of catalyst.  Operating with a ZnO-Al₂O₃ catalyst (1:4) with a CO:H₂ ratio of 1 at 300 atm. and 450°, the yields per m.³ of gas were:  Total yield C₃ and higher 120-130 gm.; C₄ (90% isobutane) 50-80 gm., C₅+(97% iso-) 30-60 gm.