The Moisture Effect on Wood Combustion in an Updraft Gasifier

This paper studies the fuel moisture content effect on the wood combustion behaviour in the gasifier. The combustion process is evaluated with the variation of fuel’s moisture content, i.e. set at 17%, 31%, and 40% respectively. The ignition front rate decreased with increasing fuel moisture content which resulted in slower gasification process in the chamber. The temperature and oxide of nitrogen (NO) concentration are decreased with the increase of the moisture in the fuel. Furthermore, the concentration of carbon monoxide (CO) increases while the change for carbon dioxide (CO2) and oxygen (O2) concentrations are only around 1% with the variation of this operating parameter. At highest gasification efficiency of 92.7%, the moisture content of the fuel is best set at 16-17%; giving outlet operating temperature of 500oC and exhaust gas concentrations with 1500 ppm of CO, 2.8% of CO2, 30 ppm of NO and 17.6% of O2 respectively.