Introduction to Biomass
Biomass Overview Biomass is defined as any organic matter that is available on a renewable or recurring basis. It includes all plants and plant derived materials, including agricultural crops and trees, wood and wood residues, grasses, aquatic plants, animal manure, municipal residues, and other residue materials. Plants (on land or in water) use the light energy from the sun to convert water and carbon dioxide to carbohydrates, fats, and proteins along with small amounts minerals. The carbohydrate component includes cellulose and hemi-cellulose fibers which gives strength to plant structures and lignin which binds the fibers together. Some plants store starches and fats (oils) in seeds or roots and simple sugars can be found in plant tissues. In 2007, biomass production contributed 3.6 quadrillion Btu of energy to the 71.7 quadrillion Btu of energy produced in the United States or about 5% of total energy production. Since a substantial portion of U.S. energy is imported, the more commonly quoted figure is that biomass consumption amounted to 3.6 quadrillion Btu of energy of the 101.6 quadrillion Btu of energy consumed in the United States in 2007 or about 3.5%. At present, wood resources contribute most to the biomass resources consumed in the United States and most of that is used in the generation of electricity and industrial process heat and steam. However, the contribution of biofuels has doubled since 2005 and now amounts to close to one third of all biomass consumed. While most biofuels feedstocks are currently starches, oils and fats derrived from the agricultural sector, whole plants and plant residues will soon be an important feedstock for cellulosic biofuels. Algae is being developed as a source of both oil and cellulosic feedstocks. The industrial sector (primarily the wood products industry) used about 1.4 quadrillion Btu in 2007. The residential and commercial sectors consume 0.06 quadrillion Btu of biomass; however, this figure may understate consumption in these sectors due to unreported consumption, such as home heating by wood collected on private property. The use of biomass fuels such as ethanol and biodiesel by the transportation sector is now at about 0.6 quadrillion Btu. This is less than the total amount of biofuels produced because some liquid biofuels are used by other sources. The Renewable Fuels Association characterized 2007 as a year that ushered in a new energy era for America. The enactment of the Energy Independence and Security Act of 2007 (H.R. 6) coupled increased vehicle efficiency with greater renewable fuel use. The law increased the Renewable Fuel Standard (RFS) to 36 billion gallons of annual renewable fuel use by 2022 and required that 60 percent of the new RFS be met by advanced biofuels, including cellulosic ethanol. To stimulate progress in this direction, the Department of Energy’s (DOE) Biomass Program awarded cost-sharing contracts in 2007 to six companies to develop commercial scale integrated biorefineries using cellulosic biomass. One of the commercial scale projects, Range Fuels, broke ground for construction of the first cellulosic ethanol biorefinery near Soperton, Georgia during 2007. An existing corn to ethanol company, Poet, LLC began construction of a cellulosic to ethanol unit at an existing facility in Scotland, S.D. during 2007. To facilitate innovation in cellulosic biomass conversion technologies, DOE awarded 9 cost-sharing contracts for the development of small-scale cellulosic biorefineries. Recipients ranged from existing pulp and paper companies and existing ethanol companies to new companies working in collaboration with universities and private sector supporters. Many new types of technologies are being developed by the small-scale biorefinery efforts (see Biorefinery Section). With the passage of the 2008 Farm Bill in May of 2008, USDA extended or instituted several programs that provide incentives for the development of advanced biofuels using cellulosic biomass. |
