Significant advances have been made to transform the feedstock supply process from tra­ditional technologies historically used in smaller distributed livestock, forage, and wood product industries to an assembly system specifically designed for the biorefinery industry.

Feedstock infrastructure development is difficult because equipment, methods, and lo­gistics vary not only among resources (e. g., agricultural residues versus forest residues), but also among geographic regions (e. g., dry agricultural residues in dryer regions versus wet agricultural residues in wetter regions). Consequently, the feedstock supply infrastructure must be developed for each class of biomass resource. Three general classes that cover the range of feedstocks are as follows:

• Dry herbaceous (examples: stover, straw, and switchgrass that are harvested at <15% moisture dry basis by weight). Dry herbaceous feedstocks present the fewest logistical challenges for use as biorefinery feedstocks. Although limited in overall volume, they pro­vide a good opportunity for near-term utilization for establishing Phase II biorefineries.

• Wet herbaceous (examples: stover and switchgrass that are harvested at >15% moisture dry basis by weight). The use of wet herbaceous feedstocks is limited by a host of infras­tructure barriers. Because wet herbaceous feedstocks represent a significant portion of the overall feedstock resource, overcoming these barriers provides the greatest potential to achieve the projected tonnage targets.

• Woody (example: logging residues). Logging residues have been used for energy in Europe and the United States for nearly 30 years. As a result, the logging residue supply system is quite mature, and systems and methods are already developed to support this industry (30). Because near-term woody feedstock will consist largely of logging residues, the infrastructure for this feedstock can be readily adapted and validated against resource environment, resource policy, and other regional factors.

The R&D activity plan for developing and validating a feedstock supply infrastructure capable of producing large tonnages of biorefinery feedstocks at the lowest possible cost addresses one of three key factors — equipment capacity, equipment efficiency, or feedstock quality — affecting feedstock supply system costs. The specific research plan that focuses on the application of these cost factors to each of the supply system elements for achieving the feedstock R&D targets is described below.

2.2.1.2.1 PRODUCTION

Production is a critical component of the feedstock supply system, and it is a key component to ensuring an adequate and sustainable feedstock supply. Specific research needed to address production issues includes:

• Assessing the cost and availability of the feedstock resource on a local basis to define production costs (e. g., grower payments) and identify regional tonnages available within each feedstock type or classification at or under the feedstock threshold costs

• Identifying and validating sustainable agronomic and silviculture practices specific to feedstock types and regional variables to ensure sustainable production

• Investigating crop production improvements (e. g., increased yields, decreased yield vari­ability, and consistent quality) through genetic modification

• Developing a perennial crop program that includes matching varieties to site conditions, establishing optimum agronomic and silviculture practices, and developing a seed pro­duction program.