Thermal characterization of Uganda's Acacia hockii, Combretum molle, Eucalyptus grandis and Terminalia glaucescens for gasification

In this paper, thermal characterization of four Ugandan woody biomass species was carried out in order to ascertain their suitability for gasification for small-scale biopower generation. The analyses and tests covered the aspects of proximate analysis, ultimate analysis, heating value, Thermogravimetric Analyses (TGA), ash melting and chemical composition. Eucalyptus grandis revealed ideal properties that make it the most promising wood specie for gasification applications. Furthermore, the low ash content in E. grandis significantly minimizes the possibilities of ash deposits on the gasifier and heat exchanger surfaces. The high fixed carbon in Terminalia glaucescens, Acacia hockii and Combretum molle makes these species ideal for charcoal making (pyrolysis). Due to high ash melting temperatures demonstrated by these samples, their pyrolysis and gasification can therefore take place with minimal worry of the ash related problems.

► The ash melting temperature of biomass species tested was higher than 1300 °C.
► Eucalyptus grandis showed ideal properties that make it most suitable for gasification.
► E. grandis gave the lowest ash and nitrogen content of 0.1% and 0.11% respectively.