THE DIRECT CONVERSION OF HYDROGEN-SULFIDE TO HYDROGEN AND SULFUR

The thermal noncatalytic decomposition of H2S has been investigated in the temperature range 1000-1200 degrees C, neat and admired with nitr ogen or helium at a total pressure of one atm. It has been found that, contrary to earlier literature claims, the inhibiting effect of the b ack reaction, the reverse reaction between H-2 and S-i (i = 1-8) molec ules to regenerate H2S, can be overcome by the use of readily attainab le, sufficiently high gas flow rates. In agreement with thermodynamic predictions, the reaction has been shown to be temperature and H2S pre ssure dependent; the experimental conversion was found to increase wit h rising temperature and declining H2S pressure. At 1200 degrees C and one atm. H2S pressure the measured conversion was 35.6% corresponding to 97.5% of the thermodynamic Limit when a steady gas flow of 50 mL/m in and residence time of 48 seconds were maintained. The highest exper imental conversion, 65.8%, was obtained at the highest temperature, 12 00 degrees C, and lowest pressure, 0.050 atm., employed. For optimum c onversions under the present experimental conditions it was necessary to use a quartz reactor packed with quartz chips. Apparently, at 1200 degrees C the chips have no catalytic effect but serve as heat transfe r agents. (C) 1998 International Association for Hydrogen Energy.