21.     ALDRICH, R. C.  Manufacture and Regeneration of Fischer-Tropsch Catalyst.  Nat. Petrol. News, vol. 37, 1945, pp. R922-R924; CIOS Rept. VI-22, X-18-SV-5, 1944, 25 pp.; PB 373.

               Operation of the Fischer-Tropsch unit of the Carrières-Kuhlmann plant at Harnes, France.  Of the operating personnel of 120 men, 40 are employed in catalyst manufacture and regeneration.  Capacity of the plant is 350 bbl. per day.  The % composition by weight of the finished catalyst before hydrogenation is:  Co 18.0.  MgO 1.8.  ThO₂ 0.9, kieselguhr 79.3%, 40-50 kg. HNO₂ (36° B.), and 90 kg. of Na₂ CO₂ per 100 kg. of catalyst.  The Co must be 99% pure, the other 1% being Cu or Ni.  ThO₂ must not contain even traces of Pb or P, and the CaO must be less than 0.2% by weight.  The kieselguhr must not contain Fe or lime.  The SiO₂ content must exceed 92%, but the sand content must not exceed a few %.  All organic matter must be removed by roasting at 800° but not greatly above, as the structure of the particles will be destroyed.  Kieselguhr from Kieselguhr-Industrie-Hannover No. 120 is one of the best both as to impurities and particle size; and Johns-Manville Filtracel is satisfactory.  Describes manufacture of the catalyst and its regeneration in great detail, together with the accompanying chemical reactions.