Bio Energy

Biomass refers to all plant and animal matter. Harvesting biomass such as crops, trees or dung and using them to generate energy in the form of heat or electricity is known as bio energy. The CO₂ released during the generation of energy from biomass is balanced by that absorbed during the fuels production, e.g. the life time of a tree. This is known as a carbon neutral process. The main bio energy sources are wood products such as:

• Wood chips: processed from willow/miscanthus or forestry tinnings/residues which have been chipped, and either forced or naturally dried.

• Wood Pellets: upgraded wood fuels which have been produced from timber by-products such as saw dust, shavings, or cutter chips which have been dried and pressed into a cylinder or ball shape.
• Logs: Logs or blocks of wood are the most familiar form of wood fuel, firewood.
• Wood briquettes: larger versions of wood pellets, similar in dimensions as firewood.

Wood pellet/chip Boilers

Suitable too many buildings, as wood pellet/chip boilers can directly replace an existing oil or gas boiler. Wood pellet/chip boilers achieve 90-95% efficiency, ensuring that most of the heat generated is transferred into the buildings central heating or hot water system.

Wood pellets/chips stored in storage hopper, which feeds boiler via an automated conveyer. Adequate space needed to accommodate an internal/external storage hopper, 2 tonne (3m³) of pellets is equivalent to 1000 litres (1m³) of heating oil. The feeding of the boiler can be completely automated resulting in no manual loading of pellets/chips. Wood pellets require less storage space and are better suited to smaller installations with a heat demand of below 100 KW. Wood Chips are generally economically justifiable when the heat demand for a building is above 100kW. Typically wood chips are 30-40% cheaper than pellets but storage / handling requirements are significantly higher. The availability of multiple fuel boilers for the burning of pellets and wood chips provides flexibility in regards to the sourcing of fuels.

Wood Gasification Boilers

 A wood gasification boiler differs from a standard wood boiler by way of the combustion process. Instead of direct combustion of the wood fuel, logs are burned in a high temperature, low oxygen environment causing gas to be released. The resulting gas mixture is called synthesis gas or syngas and is itself a fuel. The syngas is then mixed with air and burned in a separate combustion chamber.

• Can achieve efficiencies of 95%.
• Wood gasification boilers are ideally suited to areas with access to a large supply of wood logs/blocks.