Biomass is regenerative (as opposed to fossil) organic material used for energy production. Sources for biomass fuel include terrestrial and aquatic vegetation, agricultural and forestry residues, and municipal and animal wastes. Like most renewable energy sources, biomass is a form of solar energy; however, biomass is distinct from thermal processes in that energy has been transformed by photosynthesis and stored as chemical energy of the organic material. Biomass
can either be collected and burned directly or converted to other usable energy forms, such as gaseous or liquid fuels, or energy-intensive chemical feedstocks. The term biomass as a
fuel category includes many of the waste categories discussedin Chapter 22, Resource Recovery. It also includes
biomass farm concepts, where biomass is harvested solely
as a fuel.