Introduction
The synthesis of hydrocarbons from mixtures of CO and H2, commonly referred to as the Fischer-Tropsch process, was the object of a coprehensive study by the U.S. Naval Technical Mission in Europe’s Petroleum Group in Germany for April through June 1945.
This study disclosed that the process was of secondary importance in the German fuel economy, producing 9.1% of the total German oil supply. The concerted effort of German scientists to improve its two main drawbacks; very low space velocity and poor quality gasoline did not succeed which made it a poor competitor with such processes as coal tar or even coal hydrogenation. It was quite generally agreed in Germany that CO+H2 Syntheses would be used in the future as methods of producing special chemicals and chemical raw materials.
The outstanding quick ignition, ash and sulphur free quality of the diesel oil from FT synthesis would not, in the German point of view, change this picture. No attempts were made to develop engines which could make use of the 90-100 cetane number in a pure FT diesel oil as such. The Germans, being short on all types of hydrocarbons, made good use of the “Cetane” from their FT plants, however, by upgrading diesel fractions from coal tars with cetane numbers of 10-15 and thus increasing their production of 40-50 cetane diesel oil. For this purpose, GT oil was exceptionally suited. The value of cetane number is presently undergoing a re-examination and until this re-examination has been completed, the further use of the Fischer diesel oil is uncertain.
The production of chemicals via synthesis from CO+H2 was still in its early beginnings. The war has slowed down all research not directly connected with the German war effort; but two classes of compounds produced by Fischer-Tropsch synthesis, nevertheless, received particular attention; mono-olefines and high boiling alcohols. These compounds were of great interest, the first for polymerization to synthetic lube oil and for sulfonation to detergents; the second for esterification to special lubricants. The German efforts to increase and control production of these compounds were successful, in that they developed means to enrich these compounds in the primary synthesis products to concentrations of almost 70%. The ways used to obtain these yields are described in Sections 1a and 1b.
The FT synthesis is known to be but the sum-total of a great many different reactions, such as carbide formation, polymerization, hydrogenation, cracking, and isomerization. The direction of future research must necessarily be towards better insight into the chemistry of synthesis and the kinetics of the reaction. The Germans have done considerable work along this line and the information obtained from them is reported in Section 1b.
Finally, it is pointed out that only the actual synthesis is considered in this report. methods to produce the feed (“CO+H2”), as well as processes based on the primary products are described in the following U.S. NavTecMisEu reports:
(a) The production of H2 and synthesis gas from Solid and Gaseous Fuels.
(b) The Manufacture and Application of Lubricants in Germany.
(c) The Manufacture of Aviation Gasoline in Germany.
(d) German Diesel Fuels.