2754.     PRIVALOV, S. I., CHAUKAVIN, M. K., ZUEVA, V. P., AND OGARKOV, N. P.  [Synthesis of Gas Suitable for Cementation Operations.]  Vestnik metallopromy-shlennesti, vol. 19, No. 1, 1939, p. 85-91; Chem. Abs., vol. 34, 1940, p. 1286.

        Gas suitable for cementation of steel was prepared by synthesizing CH4 from CO, CO2, and H2 in the presence of a catalyst comprising pumice stone impregnated with a solution of Ni(NO3)2 containing 15% powdered Cr2O3 and reduced with H2 at 350.  The life of the catalyst was indefinite provided the temperature did not exceed 500-600 and its surface remained clean.  The temperature in the retort was maintained at 400.  If the starting gas has 4-5 times as much H2 as CO+CO2, the resulting gas did not have to be scrubbed of the CO2.