Hydrogen production by thermocatalytic decomposition of butane over a carbon black catalyst

Catalytic activity of carbon black for decomposition of butane was investigated for CO2-free hydrogen production. The carbon black employed was a rubber black and the range of reaction temperature was from 500 to 1100 °C. Although the primary decomposition of butane occurred mostly by non-catalytic thermal decomposition, the butane conversion and the hydrogen yield obtained in the presence of the carbon black were higher than those obtained by non-catalytic thermal decomposition. This is mainly due to the catalytic effect of carbon black which accelerates decomposition of butane as well as subsequent decomposition of propylene, ethylene and methane that have been produced by the primary decomposition. The catalytic decomposition of ethylene was pronounced from 750 °C and that of methane from 950 °C. A variety of products such as methane, ethylene, ethane, propylene and propane were formed, but in the presence of carbon black ethane, propylene and propane were negligible above 900 °C and ethylene was so at and above 1000 °C. Deactivation of the catalyst was not observed at least for 200 min in spite of carbon deposition.