493.    ----------------.[CHAUX, R.]   Fischer-Tropsch Research – Tracer Investigation.  Vol. 58, 1948, pp. 680-681.

                  The research project, conducted by the Gulf Oil Corp., of Pittsburgh, Pa., at Mellon Research Institute using radioactive isotopes, has possibilities of improving and perhaps greatly altering the future commercial development of the gas synthesis process by further improving the conversion methods.  The research method is the so-called “tracer” system which involves, in this case, the use of radioactive atoms (C₁₄), which are chemically identical with C but which emit electrons that can be detected by the Geiger counter at any point in the reaction and thus indicate the exact course that the reaction is taking.  It is hoped to prove whether the gasoline produced by the Fischer-Tropsch synthesis comes from the reaction of H₂ with the metal carbides formed from CO and the metal catalyst or from some other source not involving carbide formation.  In the method employed radioactive C is supplied as BaCO₃.  Acid treatment releases radioactive CO₂ and from this is produced the desired radioactive CO by exposing a mixture of the CO₂ with ordinary CO to an incandescent tungsten filament.  This radioactive CO is then reacted with an Fe catalyst to form carbide-containing radiocarbon.  The hydrocarbon products derived from passage of ordinary synthesis gas (CO+2H₂) over this catalyst will show no radioactivity if they are derived entirely from ordinary CO gas rather than from reduction of Fe carbide.  If they are derived from reduction of the Fe carbide, they will show a radioactivity comparable to that of the surface of the Fe carbide catalyst.  The C₁₄ experiments at about 250° F. show that the hydrocarbon gas formed has less than 10% of the radioactivity it would have if the entire surface of the catalyst reacted entirely through the mechanism of alternate carbide reduction formation.