Influence of Manufacturing Pressure on Properties of Sawdust–Lignite Pellets

The influence of the manufacturing pressure and the composition of pellets based on sawdust and assorted wastes and low-grade fuels on their density and mechanical characteristics (impact strength, hardness, resistance to vibrational loads) is studied experimentally. The specific additives employed are lignite, straw, and cardboard; in each case, 30 wt % of this component is added. With increase in manufacturing pressure and the use of those additives, the sample density may be increased from 2 to 8%. The pellet composition has a greater influence than the manufacturing pressure on the pellets’ characteristics. Adding cardboard increases the impact strength by 0.3–2.6%. Likewise, at fixed manufacturing pressure, the hardness increases by a factor of 1.5–2.9 on adding cardboard or lignite. The best resistance to vibrational loads is observed for sawdust pellets with no additive. The experiments show that 400 MPa is the optimal manufacturing pressure in terms of density, impact strength, hardness, and resistance to vibrational loads. The experimental results may be used in developing technologies for the production and combustion of pelletized fuels consisting of biomass and industrial waste.