B100: B100 is another name for pure biodiesel.

B20: A mixture of 20% biodiesel and 80% petroleum diesel based on volume.

Backpressure turbine: A type of steam turbine that produces low-pressure steam exhaust, which can be used as the source of heat for space heating or other uses.

Bacteria: A small single-cell organism. Bacteria do not  have an organized nucleus, but they do have a cell membrane and  protective cell wall. Bacteria can be used to ferment sugars to ethanol.

Backup system: An alternate fuel combustion system used to provide heat when the primary system is out of service or unable to meet the full heat load.

Bagasse: Residue remaining after extracting a sugar-containing juice from plants like sugar cane.

Bag house: A type of particulate removal device used with very large biomass heating plants.

Bark: The outer protective layer of a tree including  the inner bark and the outer bark. The inner bark is a layer of living  bark that separates the outer bark from the cambium and in a living tree  is generally soft and moist. The outer bark is a layer of dead bark  that forms the exterior surface of the tree stem. The outer bark is  frequently dry and corky.

Barrel (of oil): A liquid measure equal to 42 U.S. gallons, or typically about 306 lb of oil. One barrel equals 5.6 ft3; for crude oil, one barrel contains about 5.8 x 106 Btu of energy.

Basal Area: (a) The cross- sectional area (in square feet) of a tree trunk at 4.5 feet above the ground (Basal area of a tree is 0.005454 x diameter (inches)2). (b) The sum basal areas of the individual trees within 1 acre of forest. For example a well- stocked pine forest may have a basal area of 80 to 120 square feet per acre.

Base: A solution that has an excess of hydroxide ions (OH-) in aqueous solution.

Batch distillation: A process in which the liquid feed is placed in a single container and the entire volume is heated.

Batch fermentation: Fermentation conducted from start to finish in a single vessel without addition to or removal of a major substrate or product stream, respectively, until the process in complete.

Batch process: Unit operation where one cycle of feedstock preparation, cooking, fermentation, and distillation is completed before the next cycle is started.

Beer: A fermented broth that consists of water, ethanol, and small amounts of ether and assorted alcohols.

Benzene: An aromatic component of gasoline, which is a known cancer-causing agent.

Best Management Practices: Management practices that maintain and improve the environmental values of forests associated with soils, water, and biological diversity; primarily used for the protection of water quality.

Biobased product: The term 'biobased product' as defined by Farm Security and Rural Investment Act (FSRIA), means a product determined by the U.S. Secretary of Agriculture to be a commercial or industrial product (other than food or feed), that is composed in whole or in significant part, of biological products or renewable domestic agricultural materials (including plant, animal, and marine materials) or forestry materials.

Biobutanol: refers to butanol that has been produced from biomass. Biobutanol is produced by a microbial fermentation, similar to ethanol and can be made from the same range of sugar, starch or cellulosic feedstocks.

Biochar: A type of charcoal produced from biomass via pyrolysis. Often used as a soil amendment.

Bioconversion (or biochemical conversion): A general term describing the use of biological systems to transform one compound into another. Examples are digestion of organic wastes or sewage by microorganisms to produce methane and the synthesis of organic compounds from carbon dioxide and water by plants.

Biodiesel: a diesel fuel produced from plant oils or animal fats. It is commonly sold blended with diesel derived from petroleum. Common blends include "B2" (2% biodiesel), "B5" (5% biodiesel), "B10" (10% biodiesel) and "B100" (100% biodiesel).

Biochemical conversion is the process by which biomass is converted into gas (CO2/CH4), waste (compost or fertilizer) and liquid (water or C2H5OH) by using microorganisms. Biochemical conversion is a process that involves alcoholic fermentation and anaerobic digestion. A characterizing feature of biochemical conversion is the use of enzymes to perform cellulose hydrolysis. see Thermochemical conversion.

Bioenergy: energy contained in living or recently living biological organisms, a definition which specifically excludes fossil fuels.

Bioethanol: Ethanol produced from biomass feedbacks; includes ethanol produced from the fermentation of crops, such as corn, as well as cellulosic ethanol produced from woody plants or grasses.

Biofuel: Any solid, liquid, or gaseous fuel produced from organic matter.

Biogas: A gaseous mixture of carbon dioxide and methane produced by the anaerobic digestion of organic matter.

Biogasification or biomethanization: The process of decomposing biomass with anaerobic bacteria to produce biogas.

Biological oxygen demand (BOD): An indirect measure of the concentration of biologically degradable material present in organic wastes. It usually reflects the amount of oxygen consumed in five days by biological processes breaking down organic waste.

Biomass: a term for all organic material that stems from plants (including  algae, trees and crops). Biomass is produced by green plants converting  sunlight into plant material through photosynthesis and includes all  land- and water-based vegetation, as well as all organic wastes. The  biomass resource can be considered as organic matter, in which the  energy of sunlight is stored in chemical bonds.

Biomass processing residues: Byproducts from processing all forms of biomass that have significant energy potential. For example, making solid wood products and pulp from logs produces bark, shavings and sawdust, and spent pulping liquors. Because these residues are already collected at the point of processing, they can be convenient and relatively inexpensive sources of biomass for energy.

Biomass to liquid (BTL): The process of converting biomass to liquid fuels.

Bio-oil: a  dark brown liquid and has a similar composition to biomass. It has a  much higher density than woody materials which reduces storage and  transport costs. Bio-oil is not suitable for direct use in standard  internal combustion engines. Alternatively, the oil can be upgraded to  either a special engine fuel or through gasification processes to a  syngas and then bio-diesel. Bio-oil is particularly attractive for  co-firing because it can be more readily handled and burned than solid  fuel and is cheaper to transport and store.

Biopower: The use of biomass feedback to produce electric power or heat through direct combustion of the feedback, through gasification and then combustion of the resultant gas, or through other thermal conversion processes. Power is generated with engines, turbines, fuel cells, or other equipment.

Biorefinery: A facility that processes and converts biomass into value-added products. These products can range from biomaterials to fuels such as ethanol or important feedbacks for the production of chemicals and other materials.

Biofuel: Fuel such as methane produced from renewable biological resources such as plant biomass and treated municipal and industrial waste.

Bio-syngas: the name given to a gas mixture produced from  biomass gasification that contains varying amounts of CO (28-36%), H2 (22-32%), CO2 (21-30%), CH4 (8-11%), C2H4 (2-4%) and others. see Syngas, Bio-syngas, Fuel  gas, Natural  gas, Landfill  gas, Producer  gas.

Bitumen: Also, on occasion, referred to as native asphalt, and extra heavy oil; a naturally occurring material that has little or no mobility under reservoir conditions and which cannot be recovered through a well by conventional oil well production methods including currently used enhanced recovery techniques; current methods involve mining for bitumen recovery.

Black liquor: Solution of lignin-residue and the pulping chemicals used to extract lignin during the manufacture of paper.

Blast tube: A short connecting passage between a combustor and a boiler or other heat exchanger. Hot combustion gases from the primary chamber pass through the tube, sometimes with the addition of secondary or tertiary combustion air.

Board foot (BF): A measurement of the volume of lumber an area or harvest produces (1 BF = 1 foot long, 1 foot wide, 1 inch thick).

Boiler: A system used to extract heat from hot combustion gases and use it to heat water or produce steam, which can then be used to heat a building. Biomass boilers that use either wood chips or wood pellets can work to heat both small and large facilities, such as schools or hospitals.

Bole: Refers to the log that is produced after a tree is cleared of its top and limbs during harvesting.

Bone-dry-unit (BDU): 2400 lb of moisture-free wood, unless otherwise stated.

Bottoming cycle: A cogeneration system in which steam is used first for process heat and then for electric power production.

Brackish water: is water that has more salinity than fresh water, but not as much as seawater.

Brash: Low density forestry material consisting of tops of trees and small branches. Also referred to as 'lop and top'.

British thermal unit (Btu): The amount of heat required  to raise the temperature of one lb of water one degree Fahrenheit under  one atmosphere of pressure and a temperature of 60-61 degrees  Fahrenheit.

Bucket elevator: A solid fuel handling device that lifts the fuel vertically.

Bundlers: A machine that collects, compresses, and binds forest residues in to bundles.

Bound nitrogen: Some fuels contain about 0.1-5 % of organic bound nitrogen which typically is in forms of aromatic rings like pyridine or pyrrole.

Bunker: A storage tank.

Burnback: Movement of flame from the combustion chamber back along the incoming fuel stream.

Butanol: (C4H10O) or butyl alcohol is an alcohol that can be used as a solvent or fuel.

Buyback Rate: The price a utility pays to purchase electricity from an independent generator

By-product: Material, other than the principal product, generated as a consequence of an industrial process or as a breakdown product in a living system.