Lignin obtained by acidification of an alkaline extract of wood Anaerobic digestion (AD): is a biological process similar in many ways to composting. It is a natural treatment process and, as in composting, bacteria break down organic matter and reduce its bulk or 'mass'.

A reactor that is constructed to effect the degradation of organic matter by anaerobic bacteria.

The degradation and stabilisation of organic materials brought about by the action of anaerobic bacteria with the production of biogas (bio-methanisation).

Capable of being broken down biochemically by the action of micro-organisms.

A mixture of methane (CH4) and carbon dioxide (CO2) produced by anaerobic digestion, with small amounts of other gases. The methane is a flammable gas, chemically identical to the main constituent of natural gas, and can be used as a fuel for heat and/or electricity generation. Biogas is effectively the same as landfill gas, which is produced by the anaerobic decomposition of organic material in landfill sites.

Largely organic material fed into a digester, including solid and liquid wastes.

A colourless, odourless, flammable gas and a main constituent of biogas; chemical formula CH4.

is a general term for all the biological methods used for the production of methane biogas.

Any plant-derived organic matter. Biomass available for energy on a sustainable basis includes herbaceous and woody energy crops, agricultural food and feed crops, agricultural crop wastes and residues, wood wastes and residues, aquatic plants, and other waste materials including some municipal wastes. Biomass is a very heterogeneous and chemically complex renewable resource.

By-products 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.

small fragments of wood chopped or broken by mechanical equipment. Total tree chips include wood, bark, and foliage. Pulp chips or clean chips are free of bark and foliage.

One of the botanical groups of dicotyledonous trees that have broad leaves in contrast to the conifers or softwoods. The term has no reference to the actual hardness of the wood. The botanical name for hardwoods is angiosperms. Short-rotation, fast growing hardwood trees are being developed as future energy crops. They are uniquely developed for harvest from 5 - 8 years after planting. Examples include: Hybrid poplars (Populus sp.), Hybrid willows (Salix sp.), Silver maple (Acer saccharinum), and Black locust (Robinia pseudoacacia).

Perennial non-woody crops that are harvested annually, though they may take 2 to 3 years to reach full productivity. Examples include: Switchgrass (Panicum virgatum), Reed canarygrass (Phalaris arundinacea), Miscanthus (Miscanthus x giganteus), and Giant reed (Arundo donax).

The major noncarbohydrate, polypenolic structural constituent of wood and other native plant material that encrusts the cell walls and cements the cells together. It is a highly polymeric substance, with a complex, cross-linked, highly aromatic structure of molecular weight about 10,000 derived principally from coniferyl alcohol (C10H12O3) by extensive condensation polymerization. Higher heating value (oven dry basis): HHV=9111 BTU/LB (5062 CAL/G, 21178 J/G)[3].

Residential, commercial, and institutional post-consumer wastes contain a significant proportion of plant-derived organic material that constitutes a renewable energy resource. Waste paper, cardboard, construction and demolition wood waste, and yard wastes are examples of biomass resources in municipal wastes.

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.

Generally, one of the botanical groups of trees that in most cases have needle-like or scale-like leaves; the conifers; also the wood produced by such trees. The term has no reference to the actual hardness of the wood. The botanical name for softwoods is gymnosperms.

a solid lignocellulosic material naturally produced in trees and some shrubs, made of up to 40%-50% cellulose, 20%-30% hemicellulose, and 20% -30% lignin

Trees and other types of lignocelluloses materials specifically grown for brining biofuels and mass by the choice of appropriate species, sites, planting densities and harvesting schedules.

Combustion is the best known and probably the most efficient form of converting solid biomass to steam or electricity.

If organic matter is heated with insufficient oxygen to support combustions, the resulting action is called pyrolysis

Gasification is a process that converts carbonaceous materials, such as coal, petroleum, biofuel, or biomass, into carbon monoxide and hydrogen by reacting the raw material, such as house waste, or compost at high temperatures with a controlled amount of oxygen and/or steam. The resulting gas mixture is called synthesis gas or syngas and is itself a fuel. Gasification is a method for extracting energy from many different types of organic materials.

The mixture of gases produced by the gasification (BECGasification) of organic material such as biomass at relatively low temperatures (700 to 1000ºC). Producer gas is composed of carbon monoxide (CO) and hydrogen (H2) plus carbon dioxide (CO2) and typically a range of hydrocarbons such as methane (CH4). Producer gas can be burned as a fuel gas such as in a boiler for heat or in an internal combustion gas engine for electricity generation or CHP. The composition of the gas can be modified by choice of gasification parameters to be optimized as a fuel gas (producer gas) or synthesis gas which contains almost exclusively CO and H2 and is suitable for synthesis of liquid biofuels.

Energy derived from waste products such as most bioenergy like biofuels, biomass, biogas.