Characteristics of wood pellets from over-dry sawdust waste

Abstract

Wood pellets are renewable fuels from biomass which can be an alternative substitute for petroleum fuels. One of the raw materials for making wood pellets is sawdust from the sawmill industry or other wood craftsmen. Sawdust waste that dumped for a long time will reduce its moisture content (over-dry) and will be difficult to form into pellets. In this paper, we studied the effect of adding liquid solution ie. water, tapioca starch solution, pure molasses solution and dilute molasses solution on over-dry sawdust to the characteristic properties of wood pellet torrefaction. The sawdust material was collected from the wood sawmill in the Bogor District. There were five treatments i.e sawdust (control), sawdust + 10% water, sawdust + 10% tapioca starch solution, sawdust + 10% pure molasses solution, sawdust + 10% diluted molasses solution. The wood pellet torrefaction properties were investigated using a manual hot press at the temperature of 210°C. The results showed that the addition of pure molasses solution produced better pellets than other treatments, with properties i.e water content of 2.65%, the ash content of 1.45%, volatile matter 76.72%, fixed carbon 19.18%, the calorific value of 19.56 MJkg-1, density 0.84 gcm-3, and compressive strength 52.22 kgcm-2.