Abstract: The present invention provides an improved gasifier, consisting of two separate and functionally different combustion zones within a common insulated chamber. Solid carbonaceous fuel enters the gasifier through an input feed. A spindle assembly, which is affixed to one end of the chamber, rotates, causing a mixing of the fuel and facilitating its movement through the chamber. The portion of the chamber nearest the input feed acts as a first combustion zone, partially oxidizing the raw fuel and carbonizing the fuel particles. A second combustion zone completes combustion of the char produced in the first zone. One end of the spindle assembly, located between the first and second combustion zones, includes a gas collection device for removing combustible product gas from the gasifier. The gas collector is circumscribed by an auger which, rotating with the spindle, actively transports charcoal from the first to the second combustion zone.