Bulk Format Approach

Bulk-format demonstration project that included field harvest campaign of switchgrass reported in this paper. (Artwork provided by Bob Longmire, courtesy of Genera Energy.)

A bulk supply system was conceived to streamline handling at increased scale for switchgrass involving satellite storage. Instead of harvesting and storing switchgrass at high moisture, this bulk-format system uses field-dried, low moisture switchgrass biomass. Switchgrass is mowed with a mower-conditioner, raked as needed, chopped with a forage harvester, transported as loose chop to nearby storage, stored, and transported further distances to a biorefinery in a compacted bulk format using commercial waste transfer compaction equipment and trailers.

For loose chop switchgrass transported from the field to storage, dump trailers were used in lieu of walking-floor trailers due to availability at demonstration time. Bulk densities of loose chop measured in the project should be applicable to various trailer volumes. Commercial-scale transport would increase trailer volume for loose chop, and commercial storage systems would involve large stacks and associated reclaimer to minimize costs. This work reports on harvesting and transporting switchgrass placed into bin storage that simulated a core sample from a large stack.