Coal gasification by microwave plasma in water vapour

The influence of several parameters on the H₂ and CO yields from gasification of a coal (Blanzy) by microwave plasma in water vapour, in a static system, is discussed. The yields of H₂ and CO significantly increase for low coal weights placed in the discharge illustrating that the gasification occurs on the surface of the coal layer. The time necessary for complete gasification and the gasification yields are measured for several initial weights of coal. The relative yields of H₂ and CO depend on the initial water vapour pressure and are independent of coal granulometry. The reactivity of a coal which was pre-reacted in the discharge is similar to that of an original coal, so a possible recycling of the solid can be envisaged.