From Open Energy Information

Agricultural residues are defined as the residues from production of the following crops. • Corn • Wheat • Soybeans • Cotton • Sorghum • Barley • Oats • Rice • Rye • Canola • Beans • Peas • Peanuts • Potatoes • Safflower • Sunflower • Sugarcane • Flaxseed

Forest residues are defined as logging residues and other removals. These include material already utilized as well as material that is disposed as waste. Logging residues are the unused portions of trees cut by logging (tops and branches) and left to be burned or decay in the woods. Other removals include trees removed as a part of thinning projects, land clearings, and forest health uses that are not directly associated with round wood product harvests. Primary mill residues include wood materials and bark generated at manufacturing plants (primary wood-using mills) when round wood products are processed into primary wood products. Among the materials included in this category are the following • Slabs • Edgings • Trimmings • Sawdust • Veneer clippings and cores • Paper pulp screenings.

Secondary mill residues include wood scraps and sawdust generated by the following types of businesses • Pallet companies • Woodworking companies • Truss manufacturers • Wood container/pallet manufacturers • Lumber, plywood, millwork and wood panel wholesale companies.

Urban wood waste includes the following three categories: 1. Wood disposed of in municipal solid waste (MSW) and handled by MSW haulers such as household yard waste, clean construction debris, household remodeling scrap, municipal and utility tree trimmings, and wooden shipping containers (other than pallets) disposed of by retail and grocery stores. This includes clean wood residues and green waste that is sorted out of a raw MSW stream. It does not include plastics and tires. 2. Wood waste from the tree service industry, which is generally in the form of mulch (75%) and firewood (25%) from tree trimming activities 3. Wood waste from the construction and demolition industries such as clean construction debris, wood cleared from land before construction, and wood mixed in with other types of debris generated during demolition. Virgin recycled paper fibers are not included. Industrial wastes are included if the waste stream contains any clean wood that is separated from MSW.

Other sources may include: • Municipal solid waste located adjacent to urban centers • Dedicated energy crops • Manure • Vegetable crops • Liquid food processing wastes