a device for gasifying biomass waste has two each of primary chambers , fume transfer vents , mixing chambers which accept fumes from the primary chamber , afterburner chambers in fluid communication with the mixing chambers , and an exhaust duct . each secondary burner produces an initial heating flame within a vertical portion of the respective afterburner chamber , and secondary chambers are in fluid communication with the afterburner chambers . heated gases from the afterburner chambers cause heating of the secondary chambers . a portion of each primary chamber has a heat conductive floor superimposed over the respective secondary chamber , and the partition between the primary chambers is heat conductive , so that conductive and convective heating of the primary chambers occurs .