Defining Biomass Feedstock Forms

When designing appropriate systems, it is fundamental to remember that woody biomass or feedstock can be processed, stored and delivered in three different forms. These forms include unconsolidated slash, chips and other comminuted (reduced size) materials, or bundled materials. Different parts of the tree, including stumps, bark, leaves and needles, and the wood itself, may be included.

Horizontal grinder being used to comminute
biomass at a land clearing site

However, it is possible to separate different parts of the tree through storage procedures and mechanical means. These operations are explained in the Pre-Processing and Drying section. All forms can be stored in-woods or at an end-use location.

Each of the pre-processing, sorting and storage alternatives has major implications for feedstock quality and positive or negative implications for biomass use in combustion technology or bio-based product production equipment. These topics will be discussed in the following sections.

• Unconsolidated Materials
• Comminuted Materials
• Composite Residue Logs

Wood Quality is an especially important issue regardless of the form of the feedstock and is treated in the Storage section.