Effects of raw material moisture content, densification pressure and temperature on some properties of Norway spruce pellets

High-Pressure Treatment of Chinese Fir Wood: Effect on Density, Mechanical Properties, Humidity-Related Moisture Migration, and Dimensional Stability

“…Seki et al (2016) used 33 to 218 MPa extrusion force to form wood flow obtained using wood impregnated with low-molecular weight phenol formaldehyde (PF) resin. Rhén et al (2005) used high pressure (46 to 114 MPa) combined with temperature (26 to 144 °C) and moisture content (6.3% to 14.7%) to form Norway spruce sawdust pellets. It was found that high compression strength was strongly correlated with the density of the pellets obtained.…”

A Review on Biomass Densification Technologie for Energy Application

“…Generally, they found that materials with higher moisture and larger particle sizes reduce the unit and bulk density of the product, while higher process temperatures and pressures increase the unit and bulk density. Rhen et al (2005) also found a strong correlation between unit density and compression strength (i.e., high dry density corresponds to high compression strength). Tumuluru et al (2010a), in their article on pelleting DDGS, supported the conclusions that both unit and bulk density greatly depends on feed moisture and die temperature where a maximum density of 1200 kg/m 3 is achievable at temperatures of about 100°C and feed moisture content of about 5-7%.…”

“…Several researchers have found that these parameters are greatly influenced by the material's moisture content and particle size, and the process pressure and temperature (Mani et al, 2006;Rhen et al, 2005;Shankar and Bandyopadhyay, 2005). Generally, they found that materials with higher moisture and larger particle sizes reduce the unit and bulk density of the product, while higher process temperatures and pressures increase the unit and bulk density.…”

Characterisation of Pellets Made From Oil Palm Residues in Costa Rica

“…Concerning the differences in the force at break (Table 1), Rhén et al (2005) note that the compressive strength is directly influenced by the MC. However, in this case no differences are observed in the MC between both types of pellets ( Table 1), indicating that other factors may be affecting the mechanical resistance.…”

“…This variation of the density profiles of the pellets in the longitudinal and transversal directions (Table 4, Figure 1) is a consequence of the size of the particles conforming them, of the internal structure of their materials and of the temperature and pressure applied to them during the pelletisation process (Rhén et al, 2005). Concerning this, some studies suggest that the smaller the size of the particles or the size of the particles not uniform, the greater is the density of the pressing temperature and the applied pressure are the factors possibly affect the variation of density (Husain et al, 2002;Rhén et al, 2005;Gilbert et al, 2009;Lehtikangas, 2001;Larsson et al, 2008;Bergstrom et al, 2008;Serrano et al, 2011). Thus, variations in these factors are likely to cause variation in the density profile of the pellets evaluated.…”