Biomass Densification – Cubing Operations and Costs for Corn Stover

Loose plant-based biomass has a low bulk density ranging from 50 to 130 kg/m3 depending on the plant species,particle density, and particle size. Biomass densified into bales and cubes increases its bulk density to 120 to 500 kg/m3. Thehandling properties of pellets and cubes are similar to those properties for grains. The existing, well-developed, conventionalbulk handling equipment can be used to handle pelleted and cubed biomass. Although cubed biomass is easier and safer tohandle and store, it is more expensive as a feedstock for a conversion plant than biomass bales. The objective of this researchwas to develop a base cost for cubing using the existing technology. The cost of corn stover bales delivered to a biorefinery64 km (40 miles) away from an intermediate storage, including a final grinding, was estimated at $60.15/dry Mg ($54.57/dryton), whereas the cost for corn stover cubes is $71.92/dry Mg ($65.38/dry ton). These costs included $11/dry Mg ($10/dryton) payment to the farmer. The difference between the cost of baled and cubed biomass was in capital equipment andoperation costs.