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 .