The novel gasification reactor comprises a vertically oriented chamber with an upper pyrolysis section, a lower feed opening, and a primary combustion section. A lateral passage on each side and near the top of said primary combustion section each communicates with a separate secondary reaction chamber where a partially reacted feed is further reacted to form the product gas. In each passageway is a venturi nozzle or preferably a plurality of nozzles which accelerates the gas carrying entrained carbonaceous materials to produce a swirling curvilinear motion in the secondary reaction chambers. The reactor is fed by means of a plurality of hoppers and screw conveyors whereby the flow is regulated and positively fed both by gravity and the screw conveyors into rotary valve cavities in which counter rotating valves travel. The valves feed a piston which charges the reactor.