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 1792.    ---------------.  [KLYUKVIN, N. A. AND KLYUKVINA, S. S.]  [Conversion of Methane.  II.]  Jour. Chem. Ind., U.S.S.R., vol. 7, 1930, pp. 877-885; Chem. Abs., vol. 25, 1931, p. 4520-4521.

       Conversion of CH4 with H2O was carried out in an Fe tube 100 cm. long and 22 mm. in diameter.  As catalysts reduced NiO (16 gm.) and NiO (24 gm.) were used.  The gas mixture consisted of 1 vol. of CH4 and 4 vol. of steam and was passed with a velocity of 6 liter/hr.  The conversion is based on the formula CH4+H2O=CO+3H2, which at low temperature may be modified to:  CH4+2H2O=CO2+4H2, while the interaction of the reaction products may be as follows:  CH4+CO2=2CO+2H2 and H2O+CO=CO2+H2, all of which is substantiated by the composition of the resulting gas.  The best result obtained is 98.4% conversion of CH4 with 218% increase in volume, the gas containing CO2 5.8, CO 12.6, H2 80, O2 0.4, N2 0.7, CH4 0.5% and no unsaturated compounds.  A substitution even in part of Al2O3 or reduced Fe for Ni produced unsatisfactory results.  Activated vegetable C gives 100% conversion of CH4 at 800° with 142% increase in volume, while the respective figures for reduced Ni at 800° are 33.3 and 100%.  At lower temperature (500°-700°) both catalysts give about equal conversion of CH4, but the quantity of gases obtained is higher with C; this indicates that the conversion of CH4 is accompanied by decomposition of water: C+2H2O→CO2+2H2.  AT 700° the resulting gas mixtures contain 1.2% of CO2 with Ni and 10.4% with C.  It must be noted, however, that the increase in vol. is 142% with C and 218% with Ni.  The conversion of CH4 with C catalyst without H2O results at 800° in 26.9% and at 900°-950° in 100% conversion of CH4 with 100% increase in vol.  The gas is of exceptional purity, containing CO2 0.2, CO 0.8, H2 93.1, N2 5.9% and no O2, CH4 or unsaturated compounds.  To investigate more closely the catalytic action of activated C in the thermal conversion of CH4, the last 2 experiments were repeated with C in porcelain tubes instead of Fe tubes, thereby eliminating any possibility of the catalytic action by Fe.  Since the velocity of the gas was 6 l./hr. instead of 3 l./hr. as in the experiments with Ni, it can be concluded from the results that C is a less active catalyst than Ni.  With Ni the reaction begins at 300° and reaches a complete conversion of CH4 at 850°, while with C it starts only at 500°-600°, and ends with only 62.4% of conversion at 1,000°.  The test with inactivated birch C under these conditions produced at 1,000° 47.1% conversion of CH4 in a porcelain tube, and 100% conversion with 100% increase in vol. at 900° when conducted in an Fe tube; that is, equal in its activity to activated C.  From 27 gm. of C used 26.8 gm. were recovered after 8 experiments.  A catalyst containing 9 gm. of inactivated birch C and 72 gm. of Fe filings produced in a porcelain tube at 1,000° 100% conversion of CH4 with 100% increase in vol., the gas containing H2 97.5, N2 2.5% and no other products.  The results are similar to those obtained with Ni and with C in an Fe tube.  No decrease in weight of the catalyst was observed after 9 experiments.