*2.1. Feedstocks*

The switchgrass *P. virgatum* L. feedstock for this study was field-grown and harvested in Vonore, TN, USA, and processed with a tub grinder by Genera Energy, Inc., while 2-inch (50.8 mm) top pine residue samples were harvested from forest stands near Auburn, AL, USA. These residues were then dried, and both the 2-inch top pine residue and switchgrass were size-reduced in a hammer mill fitted with a 3/16-inch (4.76 mm) screen at Herty Advanced Biomaterials in Savannah, GA, USA [11].
