Effect of operating conditions on tar and gas composition in high temperature air/steam gasification (HTAG) of plastic containing waste

In this work, the high temperature air/steam gasification (HTAG) technique has been tested for a fuel in pellet form made from waste material of woody and plastic origin. The feedstock was gasified in an updraft fixed bed reactor by mixtures of air and steam (102 Nm3/h, 4% to 82% steam) preheated to 1400 °C, a temperature well above the fluid temperature of the feedstock. The produced gas was analyzed with respect to composition, including a detailed characterization of the tar. Lower heating values up to 9.5 MJ/Nm3 and gas yields as high as 3.4 Nm3/kg were reported, indicating the process to be highly efficient for waste-to-energy applications. The composition of the tars, suggested extensive cracking as a result of the high temperatures of the outgoing gas.