Physical properties and microstructure of fuel pellet made from parts of Para-rubber, She Oak and Cajuput trees

Abstract

There are plenty of biomass resources in Thailand such as agricultural residues from plantations and industrial or woody processes. Biomass in the form of a pellet has more energy density than the original form moreover it is easier to handle and has a higher strength. This study selected woody parts from commonly found trees in Southern Thailand, fuel pellets were made to examine the physical properties and microstructure. Para-rubber (Hevea brasiliensis Muell. Arg.) sawdust and the branches and leaves of She Oak (Casuarina Equisetifolia) and the Cajuput tree (Melaleuca Cajuputi) were collected from the local area to make pellets by a single unit pellet mill at 130oC and 450 psi of compression temperature and pressure, respectively. The physical properties were characterized via pellet density, moisture content, heating value and compressive strength. Moreover, the microstructure of cross section area of pellet samples from the scanning electron microscope (SEM) pictures were proposed to observe the bonding mechanism. The results show that the different raw material provided different properties. The highest pellet strength, density and heating value was achieved from Cajuput leaves.