Conventional air and steam gasification, performed at temperatures around 800 °C, produces a gas with relatively low calorific value which contains significant amounts of tar. If additional heat is provided into the gasification process via a highly preheated feed gas, a higher quality of the produced gas can be obtained. The decomposition of the solid fuel is enhanced, thereby both yield and energy content of the produced gas are increased. Moreover, a high gasification temperature favors the cracking of tar and therefore results in a cleaner product. In this work, the High Temperature Air/steam Gasification (HTAG) technique has been tested for Rofire ? , a fuel in pellet form made from waste material of woody and plastic origin. The feedstock was gasified by mixtures of air and steam (101-102 Nm 3 /h, 4 to 83% steam) preheated to 1400 °C, a temperature well above the melting point of the feedstock ash. The produced gas was analyzed with respect to composition, including a detailed characterization of the tar. High gas yields and Lower Heating Values up to 9.5 MJ/Nm 3 were reported, indicating the process to be highly efficient for waste-to-energy applications. The results also indicated extensive cracking of tars.
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