Among the six process sections for manufacturing biomass pellets, the most complex section is the crushing section. The machines used in the crushing section are also different depending on the materials. Wood-based materials such as Cylindrical wood and tree trunk require wood chippers. Straw materials such as corn straw, sunflower straw, cotton straw, soybean straw and other straw materials require a cylinder crusher, also called a cylinder grinder. Root materials require a cylinder crusher. There is a structural difference between this kind of cylinder crusher and the cylinder crusher used for straw materials. Herbaceous materials such as alfalfa and pennisetum require cylinder crushers or grass cutter.