2688.     PICHLER, H., AND ZIESECKE, K. H.  [High-Pressure Hydrogenation of Carbon Monoxide Preferably to Isoparaffinic Hydrocarbons.  (Isosynthesis).  I.]  Brennstoff-Chem., vol. 30, 1949, pp. 13-22; Fuel Abs., 1949, No. 2,913.

        Isosynthesis is defined as the high-pressure hydrogenation of CO at pressures exceeding 30 atm., preferably between 300 and 600 atm., and about 450°.  ThO₂ has been found to be the best simple catalyst.  ZrO₂, CeO₂, and, to a much less extent, Al₂O₃ are suitable also.  Gaseous and liquid hydrocarbons are formed in which, for example, the C₄ hydrocarbons are 80-90% of a branched nature.  If the pressure is too high (above 600 atm.) and the temperature too low (below 400°), considerable quantities of compounds containing O₂ (most of all MeOH, isobutanol, and dimethyl ether) are formed.  At 600 atm. and 450° with ThO₂ catalyst, a yield of about 154 gm. was obtained, which consisted of 34.5% liquid products, 29.3% iso-C₄, 14.7% C₃ and n-C₄, and 18.2% C, and C₂ hydrocarbons beside dimethylether.  By working in several stages, the yield at moderate pressures could be considerably increased.  In circulation experiments the CO:H₂ working ratio could be widely shifted in the direction of H₂ consumption.