Densification of corn stover

Densification characteristics of com stover under single and multiple compression cycles was studied. Under single compression at 100 to 150 MPa pressures, pellets with relaxed densities of 830 to 1000 kg m^-3 were produced at 10 to 15% moisture contents. The durability of pellets ranged from 52 to 84%. Moisture content (10 to 15%) and com stover-grind particle size (0.66 to 0.8 mm) affected the density, durability and specific energy consumption during single-compression pelleting of corn stover. Multiple compression with two to four compression cycles at 100 to 150 MPa produced 5 to 10% more dense, and 11 to 27% more durable pellets than single compression of com stover with geometric mean particle size of 0.8 mm at 10% moisture content. Specific energy required for pelleting corn stover ranged from 0.08 to 0.22%, and 0.22 to 0.47% of the energy content of the corn stover for single compression, and multiple (two to four) compression pelleting, respectively. Multiple-compression pelleting appears to be a promising pelleting technique to produce high quality pellets with less energy than conventional pelleting.