Gasification of wood pellets in a bench-scale updraft gasifier

Biomass gasification is proving to be an alternative technology to the use of fossil fuels for energy production. The article considers the bench-scale, air-blown updraft gasification of biomass wood pellets. The objective of the study was to understand the characteristics of evolved gases from the gasifier that was built and assembled at the University Laboratory. Wood pellets of diameter 5 mm, length between 5 and 20 mm constitute the feedstock used. The experimental investigation reveals the major gases produced are CO2, CO, and H-2, while CH4 and other hydrocarbons are minor. However, the gasifier used is initially preheated to a temperature of about 800 degrees C. This is indicated by the thermo-couple readings (T1-T8) with T6 as the standard thermo-couple. When T6 attains a steady state at 800 degrees C, the gasifier is turned into a self-sustaining gasification condition. The entire experiment takes about four (4) hours to complete and this gives an understanding of evolved gases from the entire gasification process in the inside of the batch-scale updraft gasifier.