Patent ID: 8377155

Claim:
A gasification method, comprising: providing a gasifier comprising an elongated horizontally disposed stationary gasifier chamber, said chamber having a first end with an inlet for receiving gasifiable materials into its interior and a second end with outlets for discharging a gas stream and a solid residue remaining after gasification of said gasifiable materials, the horizontal position of said elongated stationary chamber defining an upper and a lower side, with a plurality of openings in the lower side, a rotatable screw conveyor extending through said chamber's interior from proximate said first end to proximate said second end for moving materials therethrough, which said screw conveyor can be raised and lowered in relation to the lower side of the chamber, a plurality of particles disposed in the interior of said chamber means above the plurality of openings in the lower side thereof, a plurality of air distribution conduits in communication with said plurality of openings in the lower side of the chamber supplied with pressurized air from a pressurized air supply source such that said pressurized air supply source is in direct communication with the interior of the chamber via said plurality of openings in the lower side thereof, said plurality of air distribution conduits emitting air into the interior of the chamber from said pressurized air supply source through said plurality of openings at pressures sufficient to substantially fluidize the particles located above said plurality of openings to form a fluidized bed, a bed dam proximate said lower side and second end that can be raised and lowered in conjunction with said screw conveyor, and wherein said chamber has a vertical diameter greater than its horizontal diameter; and gasifying materials placed in said gasifier so as to generate the gas stream and the solid residue remaining after gasification of said gasifiable materials, including supplying air and gasifiable materials to said gasifier, including inputting air via said plurality of openings so as to substantially fluidize said particles and form a fluidized bed, and inputting a batch of gasifiable materials into the interior of the gasifier chamber via said inlet and elevating the rotatable screw conveyor as necessary to accommodate said materials, rotating and lowering said rotatable screw conveyor as necessary to assure full gasification while moving and tumbling said batch of gasifiable materials from said first end to said second end as they are gasified while using said fluidized bed to support said gasifiable materials as they are moved from said first end to said second end, and discharging solid residue through a gap in said bed dam while using said bed dam to prevent particles forming said fluidized bed from being swept from the chamber when said screw conveyor is rotated to move and tumble said gasifiable materials from said first end to said second end, said bed dam being raised and lowered in conjunction with said screw conveyor.