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1724. KELLER, K., AND KLEMPT, W. [Catalytic Conversion of Gases Containing Methane Into Carbon Monoxide and Hydrogen.] Ber. Gesell. Kohlentech., vol. 3, 1930, pp. 230-261; British Chem. Abs., 1931, B, p. 325.
Reaction studied were (1) CH4+H2O=CO+3H2 and (2) CH4+O=CO+2H2. The composition of the gas used was approximately 2% CO2, 2% CnHm, 0.5% O2, 6% CO, 26% CH4, 55% H2, and 8% N2. Poisoning of the catalyst by S compounds present in the gas appears to be due to the formation of NiS, which, at suitable temperatures, can be decomposed by oxidation with steam and, thus, prevented from deactivating the catalyst completely. Since reaction (1) is endothermic, considerable, difficulty was experienced in maintaining the catalyst at the high temperature required when pure steam was used. In the large-scale experiments, a study was made of the best method of combining reactions (1) and (2) to prepare a H2-N2-CO mixture in proportion suitable for the subsequent production of a H2-N2 mixture in the proportions of 3:1. A vertical furnace of alloy steel packed with catalyst was heated externally by gas, and the gas mixture with regulated volumes of steam and air was passed in at the base of the catalyst. With this furnace, which had a layer of catalyst 94 cm. long by 12 cm. in diameter, 6 m.3 of gas, 3 kg. of steam, and 3 m.3 of air per hr. produced a gas containing (%) CO2, 2; CO, 17; H2, 56.5; N2, 24.5; CH4, traces. The highest temperature in the tube was 1,050°. In the absence of air it was only possible to convert 3.5 m.3 of gas per hr. into a CH4-free mixture. Increase in the amount of steam does not in all cases increase the CH4 conversion. In experiments on the carrying out of the reaction in two stages, the catalyst was divided into 2 separate portions. Gas and steam were passed through the first lower-temperature portion and air was added at suitable intervals along the second length of the catalyst. In this way the CH4 content could be reduced to 0.03-0.09% when a 3:1 H2-N2 mixture was required.