2337.     MÜLLER, F.  [Low-Temperature Carbonization of Coal in Conjunction With the Fischer-Tropsch Hydrocarbon-Synthesis Process.]  Tech. Mitt. Krupp, Tech. Ber., vol. 6, 1938, pp. 47-49; Brennstoff-Chem., vol. 20, 1939, pp. 141-144; Chem. Abs., vol. 33, 1939, pp. 6025, 9590.

        It was previously pointed out that, by using low-temperature coke for water-gas production for the Fischer-Tropsch process instead of high-temperature coke, a maximum oil yield would be attained.  When using low-temperature tar as fuel oil, the importance of mixing it with other oils is not as great as was formerly assumed.  Moreover, low-temperature tar can be used directly as fuel oil.  The low-temperature carbonization of coal in combination with the Fischer-Tropsch process is particularly suitable where coke ovens are not available, and gas production is not of interest.  In this way, the yield of clean oil amounts to 20-30% more than with high-temperature carbonization.  Moreover, because of the specifically better usefulness of low-temperature coke for the water-gas process, a saving of coal is obvious.  It is immaterial whether gas coal or flame coal is used, since both of  them will yield an appropriate coke in indirectly heated ovens.  Moreover, the water gas made from low-temperature coke more nearly meets the specified composition for synthesis gas – a CO:H₂ ratio of 1:2 – the water gas from high-temperature coke showing a ratio of 1:125 and that from low-temperature coke 1:1.15-1.6.