Return to Abstracts of Literature

Return to Abstracts of Literature 1250-1499

Literature Abstracts

 1336.    HALL, C. C., CRAXFORD, S. R., GALL, D., AND SMITH, S. L.  Medium-Pressure Synthesis With Iron Fixed-Bed Catalysts and Operation of the Fischer-Tropsch Synthesis in the Liquid Phase – Interrogation of Dr. H. Kölbel, Rheinpreussen.  BIOS Final Rept. 1712 (Interrogation Rept. 679), December 1947, 7 pp.; PB 91,925.

       Good catalyst composition was found to be, in parts by weight:  Al₂O₃, 3.4; Fe₂O₃, 46.3; CaO, 40.7; MgO, 6.5; CuO, 3.1; K₂O, 0.5; CO₂, 40.1; the main constituents being Fe and dolomite.  the catalyst was prepared by precipitation from the nitrates by Na₂CO₃ solution.  The critical step was the pretreatment in synthesis gas at 240°-280° at atm. pressure for 3-24 hr.  The gas was recirculated in the proportion of 9 parts of recycle gas to 1 of fresh gas at a minimum space velocity of 1,000 vol. per vol. catalyst per hr.  After cooling the catalyst, synthesis is started at 10 atm. and the full space velocity (100-150), the temperature varying from catalyst to catalyst.  Multistage operation is preferred, with recirculation of the residual gas.  With 3 stages, a Co-conversion of 90-95% can be obtained at an overall space velocity of 150.  Investigation of operation in the liquid phase with the catalyst suspended in oil of Diesel oil composition was carried out over several years with favorable results.  The usual catalyst composition was Fe, 100; Cu, 0.2; K₂CO₃, 1.0.  Some performance data are given.  Using a benzine-forming catalyst at 8-10 atm., 230°, and a space velocity of 75 vol. gas per vol. reaction space per hr., the synthesis gas has a H₂ : CO ratio of 0.5:1 and a total yield of 168 gm. per m.³ was obtained with a utilization ratio of H₂ : CO = 0.5:1.  No CH₄ was detected, and the amount of C₂H₆ was very small.  Distribution of the product was:  C₃-C₄, 19.6%; 35°-200°, 55%; 200°-320°, 20.8%; 320°, 5.6%.  The fraction 35°-150° contained 60% olefins.  Using catalysts that tended to produce wax, as much as 67% of the total product was obtained as such.  It was observed that the Diesel oil used as the liquid medium took part in the reaction and was converted to wax.