NOVELTY - The multi-chamber system for converting carbonaceous feedstock such as coal and/or switchgrass to syngas and slag, comprises horizontally oriented primary chambers for conversion of carbonaceous feedstock to a processed feedstock/char and a primary chamber gas, vertically oriented secondary chambers for conversion of processed feedstock/char to a residue and a secondary chamber gas, and gas reformulating chambers (4) comprising a zone in fluid communication with primary and secondary chamber gas outlets for conversion of the primary and/or secondary chamber gas to a processed syngas.    USE - The multi-chamber system is useful for converting carbonaceous feedstock such as coal and/or switchgrass to syngas and slag (claimed) such as hydrogen, carbon monoxide, carbon dioxide and methane, which is useful for the production of electricity and useful as primary building blocks for manufacturers of chemicals and transportation fuels.    ADVANTAGE - The multi-chamber system ensure simple, efficient, economic and complete conversion of the carbonaceous feedstock into a syngas product having a consistent and/or specified composition.    DETAILED DESCRIPTION - The multi-chamber system for converting carbonaceous feedstock such as coal and/or switchgrass to syngas and slag, comprises horizontally oriented primary chambers for conversion of carbonaceous feedstock to a processed feedstock/char and a primary chamber gas, vertically oriented secondary chambers for conversion of processed feedstock/char to a residue and a secondary chamber gas, gas reformulating chambers (4) comprising a zone in fluid communication with primary and secondary chamber gas outlets for conversion of the primary and/or secondary chamber gas to a processed syngas, melting chambers for converting the residue from the secondary chambers to slag, and a control system to regulate the operation of the system. Each primary chamber comprises a primary and a secondary feedstock inlet, a first air input means, an optional process additive input, a primary chamber gas outlet, and a processed feedstock/char outlet. Each secondary chamber comprises a processed feedstock/char inlet for receiving processed feedstock/char from the primary chambers, a second air input means, an optional process additive input, a secondary chamber gas outlet, and a residue outlet. The gas reformulating chambers further comprises an optional process additive input, a syngas outlet, and sources of reformulating heat. Each melting chamber comprises a residue inlet in communication with the residue outlet of the secondary chambers, sources of melting heat, and a slag outlet. The sources of reformulating heat are a plasma system, and a hydrogen burner. The secondary feedstock inlet is used for input of feedstock additives. The first input means and second air input means receive heated air from a syngas-to-air heat exchanger. The primary and secondary chambers comprise means for controlling the residence time having a controllable solids removal means. The controllable solids removal means comprises a rotating arm, a pusher ram, or a set of screws. The sources of melting heat are a plasma system, a gas burner or a Joule heating element. The control system comprises sensing elements for monitoring and obtaining data regarding operating parameters within the system, and response elements for adjusting operating conditions within the system according to the data obtained from the sensing elements.    DESCRIPTION OF DRAWING(S) - The figure shows multi-chamber carbonaceous feedstock gasification system.    Volatilization chamber (1)    Char conversion chamber (2)    Solid residue conditioning chamber (3)    Gas reformulating system. (4)