Wood pellet, biomass fuel, is a fuel product compressed from milled wood. The raw material is mostly dry sawdust, grinding dust, and cutting shavings or other by-products of mechanical wood processing industry. The pellet can also made from fresh biomass, bark, and forest chips as well but the raw material must be milled and dried before pelletising. The wood pellets can not touch directly with water or moisture because it will get damp, expand, and disintegrate.