Monday, May 5, 2008 - 1:30 PM
5-01
Wet harvested biomass: supply chain options and storage cost estimates
Mark Delwiche and Corey Radtke. Biosciences, Idaho National Laboratory, 2525 North Fremont St., Idaho Falls, ID 83415-2203
Tremendous tonnage and diversity of biomass feedstocks for biofuel production are necessary to meet DOE identified petroleum offset goals. Agricultural residues represent a large quantity of lignocellulosic biomass potentially available for this purpose. Much of this biomass will be relatively wet at harvest, well over 30% moisture, and is produced in regions where field drying can be risky due to weather patterns. This biomass harvested at high moisture content poses significant cost barriers in the feedstock supply chain due to the excess weight of water and aerobic microbial instability. In response we identified seven pathways for delivery of biomass from the farm to a biochemical or thermochemical refinery. These pathways range from a dry “pioneer” bale system, where total 2007 storage costs were estimated at $10/DMT; to a fully wet supply chain analogous to current silage systems, where storage cost estimates ranged between $11 and $35/DMT. Additionally, several innovative wet/dry hybrid systems were identified that could generate cost savings through co-product production from soluble sugars otherwise lost in silage fermentations. Wet/dry hybrid systems also allow the potential to process the biomass into an advanced uniform, commodity-type material for additional cost savings in transportation and handling. The storage pathways will be presented, a cost analysis provided, and cost barriers and process saving opportunities identified. Analyses of supply chain pathways with respect to a given geographical area may lead to a recommended system for handling wet harvested biomass.