Solid fuel gasifying method, involves reducing oxygen concentration of freeboard-gasification agent such that temperature at upper ends of freeboard is adjusted, where temperature lies below critical slag intermediate point

摘要

The method involves discharging a gasification agent mixture with oxygen, water vapor and/or carbon dioxide into a fluidized bed (6), a moving bed (5) and a freeboard (8) formed over the bed (6). Oxygen concentration of a fluidized bed-gasification agent (17) is increased such that temperature in a reaction chamber (4) of the fluidized bed is adjusted. Oxygen concentration of a freeboard-gasification agent (20) introduced into the freeboard is reduced such that temperature at upper ends (30) of the freeboard is adjusted, where the temperature lies below a critical slag intermediate point. An independent claim is also included for a device for gasifying a solid fuel in a fluidized bed under high pressure.