3068.     SCHENCK, R., AND ZIMMERMANN, F.  [Decomposition of Carbon Monoxide and Chemical Equilibrium in the Blast Furnace.]  Ber. deut. chem. Gesell., vol. 36, 1903, pp. 1231-1251; Jour. Chem. Soc., 1903, II, pp. 423-425.

        Reversible reaction 2 CO=CO₂+C has been studied as a true reaction in the presence of metals and metallic oxides.  The metals employed, Fe, Co, and Ni and their oxides, were deposited on pumice, which had been reduced in a stream of pure H₂ and then extracted with diluted HCl.  By this means, the whole of the original Fe compounds in the pumice were removed.  The oxides were obtained by saturating the pumice with solutions of the metallic nitrates and then strongly heating.  The oxides of Co and Ni completely oxidize CO to CO₂ at 445° and they are reduced to the metallic state.  With Fe oxide only part of the CO is oxidized.  With a gaseous mixture containing 1 CO:4 CO₂ no reduction of the Fe oxide occurs, and the pressure remains constant.  The CO₂ obtained by Boudouard must have been due tot he oxidation of the CO by the Fe oxide and not to the catalytic decomposition of the CO.  Finely divided metals accelerate the decomposition of CO into C and CO₂ in a remarkable manner.  With Ni at 445° the reaction has been shown to be bimolecular and should be represented as 2 CO=C+CO₂; at 310° and 360°, however, the reaction appears to be unimolecular and probably occurs in 2 stages:  CO=C+O and then CO+O=CO₂, the 2d reaction proceeding much more rapidly than the first.  The reaction does not appear to be complete but is reversible, and a state of equilibrium is established even at temperatures of 445°.  When Co is used, the numbers agreed with neither a unimolecular nor a bimolecular reaction.  This probably is due to Fe contained as an impurity in the Co.  When Fe is used, the pressu7re never becomes absolutely constant so long as any gas is present, and ultimately the whole of the C present is deposited in the free state and Fe oxide is formed.  It would appear that the Fe first reacts as a catalyzer, decomposing the CO into C and CO₂.  When the concentration of the CO₂ has increased and that of CO decreased to a certain limit, the metal begins to reduce the CO₂, and the 2 reactions then proceed simultaneously so that the composition of the gas remains the same.  Experiments made at 360° and 445° indicate that the reaction is unimolecular but that at 508° it becomes bimolecular.  The compositions of the gaseous mixtures are as follows:

        360°            10.5% CO and 89.5% CO₂,

        445°            52.8% CO and 47.2% CO₂,

        508°            47.1% CO and 52.9% CO₂.

The numbers obtained at 260° probably indicate the presence of some oxide other than ferric oxide.

        SCHENCK, R., FRANZ, H., AND LAYM ANN, A.  [Equilibrium Investigations in the Reduction Oxidation and Carburization Processes of Iron.  XI.]  See abs. 3060.

        SCHENCK, R., FRANZ, H., AND WILLEKE, H.  [Equilibrium Relations in the Reduction, Oxidation, and Carburization of Iron.  IX.  (10).  Influence of Foreign Oxides Upon the Equilibria.]  See abs. 3058.

        SCHENCK, R., KRÄGELOH, F., AND EISENSTECKEN, F.  [Equilibria in the Reduction, Oxidation, and Carburization of Iron.  II.   Methane-Hydrogen Equilibria in the Presence of Cobalt.]  See abs. 3051.