A gasification system having a combustor vessel, an optional scrubber vessel, an optional fixer vessel, an optional cyclone vessel and an optional demister vessel. A wide variety of possibly moist solid or semi-solid carbonaceous fuels may be partially combusted in the combustor to generate a combustible gas and a mineral ash. An improved ash support and removal subsystem reduces clogging and other problems. The combustible gas is conveyed by optional heavy-duty blowers through the optional vessels to remove liquids and particulates and to undergo catalytic chemical reactions to provide a relatively clean, dry, highly-combustible hydrocarbon gas that captures a relatively high fraction of the potential heating value of the fuel. Internal gases, liquids and particulates from the vessels may be recycled inside the system to improve efficiency and prevent liquid waste. A portion of the internal liquids may also be extracted for other uses.