629.    COTTON, E.  Germany’s Fischer-Tropsch Process.  Summary of Latest Developments and Operating Procedures.  Nat. Petrol. News, vol. 38, No. 23, 1946, pp. R425-426, 428, 430, 432-434; Chem. Abs., vol. 42, 1948, p. 9112; PB 12,613, 1946, 16 pp.

      Summary of the investigations by United States Technical Oil Mission.  Discusses the commercial methods of preparing and purifying synthesis gas by the water-gas process and the CH₄-O₂ process; the preparation of the standard Co catalyst (100Co-5ThO₂-SMgO-180-200 kieselguhr) by precipitation from the nitrates and its reduction in a stream of gas (75H₂-25N₂) at 460° and a space velocity of 8,800 for 40-60 min.; the type of reactors employed for both the normal and medium-pressure processes; and the actual synthesis procedure and the products obtained.  Also included is some information on the gas recycle operation and some details of the development of the Fe catalyst.  The latter is made by pasting Fe powder prepared by thermal decomposition of Fe carbonyl with 1% of borax and forming into approximately 1-cm. cubes, which are sintered and reduced with H₂ at 800°-850° for 4 hr.  An interesting development in the use of the Fe catalyst is the hot-gas recycle process in which gas is circulated over the catalyst and through a cooler at such a rate that the temperature rise in the catalyst bed is limited to a maximum of 10°.  The reaction is carried out at a pressure of 300 p.s.i. with a gas-recycle ratio of 10 vol. of recycle to 1 vol. of fresh feed; contact time in the catalyst bed is approximately 0.5-1 sec./pass, with a gas velocity of about 1 m./sec.  Another interesting development in the use of the Fe catalyst is the fixed-bed, oil-circulation process by which the heat of reaction is removed by circulating a product cut of fixed boiling range over the catalyst.  The heat is removed by raising the temperature of the oil as well as by partial vaporization of the oil.  The process operates at 20-25 atm. and 250°-300° in the first stage and 280°-330° in the second stage.  Synthesis gas with a ratio of CO:H₂=55:45 is used.  The throughput is controlled to yield 20-25 gm. of total product/1. of catalyst/hr.  The catalyst is the same as that used in the hot-gas recycle process.

     COUDRAY, R.  See abs. 2720, 2721.

     COUFALIK, F.  See abs. 3187.