Study on pelletization characteristics of Flammulina velutipes residues

Objective  To investigate the pelletization characteristics of Flammulina velutipes residues combined with biomass densification technology and explore a new approach to energy utilization of F. velutipes residues.

Method  The pellets were densified by universal mechanical test mechanism. The effects of moisture content, temperature, compression force and particle size on the quality of pellets were studied using relaxed density (RDS), Meyer hardness (H_M) and specific energy consumption (SEC) as technical indexes of densifying fuel. The cross-section microstructure of the pellets was observed by scanning electron microscope (SEM) to further verify the effects of densification conditions on pelletization results.

Result  The residues were all compressed and formed in the stated ranges of moisture content, temperature, compression force and particle size. Combining three pelletization indexes, the optimum technological parameters of F. velutipes residue molding were confirmed as: moisture content 11%–14%, temperature 100–120 ℃, compression force 3–5 kN and particle size 0–5 mm. SEM observation indicated that the increases of temperature and compression force in reasonable ranges could make the combination of pellet particles closer.

Conclusion  F. velutipes residue has a good pelletization performance and is a kind of relatively easily densified biomass material.