Studies on the reactivity of deposited carbon

The purpose of this work was to study the reactivity to carbon dioxide of carbon deposited by the thermal cracking of methane on metallic iron powder, with a view to evolving a process for the production of synthesis gas from natural gas. The various method of carbon-reactivity measurement and type of carbon available for gasification processes are discussed. Existing processes which utilise natural gas for the production of synthesis gas are criticised and the benefits of a process in which separate streams of hydrogen and of carbon monoxide are produced continuously from natural gas are indicate. Consideration is given to the state of knowledge on the thermodynamics and kinetics of the thermal decomposition of methane and of Boudouard reaction, and to the published evidence for the enhanced reactivity of deposited carbon as compared with graphite. As a basis for comparison a number of preliminary experimental studies have been made of the reactivity to carbon dioxide of powdered metallurgical coke in both fixed and fluidized beds and the effects of reactor temperature, gas flowrate, and the disposition of the bed. The results obtained were found to agree well with published data. A large scale laboratory fluidized bed gasifier has been developed together with a system of two katharometers to give continuously a complete analysis of a gas containing carbon dioxide, carbon monoxide and nitrogen. This reactor was supplied with powdered haematite iron ore which was reduced to metallic iron in the fluidized State with hydrogen. The iron powder was fluidized with a mixture of nitrogen and methane at about 130