F
Farmgate price: A basic feedstock price that includes cultivation (or acquisition), harvest, and delivery of biomass to the field edge or roadside. It excludes on-road transport, storage, and delivery to an end user. For grasses and residues this price includes baling. For forest residues and woody crops this includes minimal comminution (e.g. chipping).
Fast pyrolysis: Pyrolysis in which reaction times are short, resulting in higher yields of certain fuel products, which may range from primary oils to olefins and aromatics depending on the severity of conditions.
Fatty acid: A fatty acid is a carboxylic acid (an acid with a -COOH group) with long hydrocarbon side chains.
Feedstock: refers to the crops or products, like waste vegetable oil, that can be used as or converted into biofuels and bioenergy.
Feller-buncher: A self-propelled machine that cuts trees with giant shears near ground level and then stacks the trees into piles to await skidding.
Fermentation: Conversion of carbon-containing compounds by microorganisms for production of fuels and chemicals such as alcohols, acids, or energy-rich gases.
Fermentation vat.: A hermetically sealed, cylindrical vessel for the culturing of microorganisms in a nutrient medium under sterile conditions, intensive mixing, continuous aeration with sterile air, and constant temperature.
Fiber products: Products derived from fibers of herbaceous and woody plant materials; examples include pulp, composition board products, and wood chips for export.
Fine materials: Wood residues not suitable for chipping, such as planer shavings and sawdust.
Firm power: (firm energy) Power which is guaranteed by the supplier to be available at all times during a period covered by a commitment. That portion of a customer's energy load for which service is assured by the utility provider.
Fischer–Tropsch process (Fischer–Tropsch Synthesis): is a catalyzed chemical reaction in which synthesis gas, a mixture of carbon monoxide and hydrogen, is converted into liquid hydrocarbons of various forms.
Filtration: is commonly the mechanical or physical operation which is used for the separation of solids from fluids (liquids or gases) by interposing a medium through which only the fluid can pass. Oversize solids in the fluid are retained, but the separation is not complete; solids will be contaminated with some fluid and filtrate will contain fine particles (depending on the pore size and filter thickness). Filtration is also used to describe some biological processes, especially in water treatment and sewage treatment in which undesirable constituents are removed by adsorption into a biological film grown on or in the filter medium.
Fixed bed: A bed of closely spaced particles through which gases move up or down for purposes of gasification or combustion.
Fixed carbon: The carbon remaining after heating in a prescribed manner to decompose thermally unstable components and to distill volatiles. Part of the proximate analysis group.
Flail Delimber: A machine used for delimbing tree stems. Flails are mounted on spinning drums that mechanically beat the limbs from the tree stem.
Flash point: The temperature at which a combustible liquid will ignite when a flame is held over the liquid; anhydrous ethanol will flash at 51 degrees Fahrenheit.
Flash vacuum pyrolysis (FVP): Thermal reaction of a molecule by exposing it to a short thermal shock at high temperature, usually in the gas phase.
Flexible-fuel vehicle: A vehicle that can run alternately on two or more sources of fuel; includes cars capable of running on gasoline and gasoline/ethanol mixtures, as well as cars that can run on both gasoline and natural gas.
Flow control: A legal or economic means by which waste is directed to particular destinations. For example, an ordinance requiring that certain waste be sent to a landfill is waste flow control.
Flow rate: The amount of fluid that moves through an area (usually pipe) in a given period of time.
Fluid coking: A continuous fluidized solids process that cracks feed thermally over heated coke particles in a reactor vessel to gas, liquid products, and coke.
Fluidized bed: A gasifier or combustor design in which feedstock particles are kept in suspension by a bed of solids kept in motion by a rising column of gas. The fluidized bed produces approximately isothermal conditions with high heat transfer between the particles and gases.
Fly ash: Small ash particles carried in suspension in combustion products.
Flying Dutchman: A device commonly installed in round fuel silos to knock fuel down into the base of the silo, for transport by the fuel handling equipment to the combustion appliance.
FOB : An acronym for free on board, indicating that the price quoted includes loading on or in the specified container.
Foliage : trees and other plant leaves, considered as a group.
Forest land: Land at least 10 percent stocked by forest trees of any size, including land that formerly had such tree cover and that will be naturally or artificially regenerated; includes transition zones, such as areas between heavily forested and nonforested lands that are at least 10 percent stocked with forest trees and forest areas adjacent to urban and built-up lands; also included are pinyon-juniper and chaparral areas; minimum area for classification of forest land is 1 acre.
Forest health: A condition of ecosystem sustainability and attainment of management objectives for a given forest area; usually considered to include green trees, snags, resilient stands growing at a moderate rate, and removal of dead and dying tree.
Forestry residues: Includes tops, limbs, and other woody material not removed in forest harvesting operations in commercial hardwood and softwood stands, as well as woody material resulting from forest management operations such as pre-commercial thinnings and removal of dead and dying trees.
Forwarder: A self-propelled vehicle to transport harvested material from the stump area to the landing. Trees, logs, or bolts are carried off the ground on a stake-bunk, or are held by hydraulic jaws of a clam-bunk. Chips are hauled in a dumpable or open-top bin or chip-box.
Fossil fuel: A carbon or hydrocarbon fuel formed in the ground from the remains of dead plants and animals. It takes millions of years to form fossil fuels. Oil, natural gas, and coal are fossil fuels.
Fouling: The coating of heat transfer surfaces in heat exchangers such as boiler tubes caused by deposition of ash particles.
Fructose: or fruit sugar, is a simple monosaccharide found in many plants. It is one of the three dietary monosaccharides, along with glucose and galactose, that are absorbed directly into the bloodstream during digestion.
Fuel cell: A device that converts the energy of a fuel directly to electricity and heat, without combustion.
Fuel cycle: The series of steps required to produce electricity. The fuel cycle includes mining or otherwise acquiring the raw fuel source, processing and cleaning the fuel, transport, electricity generation, waste management, and plant decommissioning.
Fuel gas: same as synthesis gas or syngas. see Syngas, Bio-syngas, Natural gas, Landfill gas, Producer gas.
Fuel oil: A heavy oil, black in color, used to generate power or heat by burning in furnaces.
Fuel treatment evaluator (FTE): A strategic assessment tool capable of aiding the identification, evaluation, and prioritization of fuel treatment opportunities.
Fuel Treatment Thinnings : The process of harvesting trees and underbrush from the forest to reduce the risk of wildfires.
Fuel wood: Wood use for conversion to some form of energy, primarily for residential use.
Full Cost Method : Cost accounting method that allocates the total production cost across biomass and conventional wood products.
Fungi: Fungi are plant-like organisms with cells with distinct nuclei surrounded by nuclear membranes, incapable of photosynthesis. Fungi are decomposers of waste organisms and exist as yeast, mold, or mildew.
Furfural: An aldehyde derivative of certain biomass conversion processes; used as a solvent.
Furnace: An enclosed chamber or container used to burn biomass in a controlled manner to produce heat for space or process heating.