Biomass Boiler Technology

Solution advantages

  • Efficient use of renewable sources
  • Local availability of fuel
  • Carbon neutral fuel
  • Heating technology for all output levels

Heat from wood

In recent years, wood has been gaining popularity as heating fuel. Each year more than 380 million m³ of wood produced sustainably from European forests is on the market, 40 % thereof being used for heat generation in Europe. It is a regional fuel - the economy benefits from short transport routes, local jobs and domestic value creation. Moreover, wood is carbon neutral as a renewable resource: when burned, the same amount of CO2 that was absorbed by the tree during its growth is released. Automated firing systems provide a lot of comfort, making wood in no way inferior to oil and gas.

Pellets, split logs and wood chips

Modern heating systems use wood in the form of pellets, wood chips or split logs. Wood pellets are small, standardised, cylindrical pieces made from natural, untreated wood. In order to produce pellets, the wood chips occurring in the sawmill are first dried, then cleaned and pressed into pellets in matrices. 2 kg of wood pellets correspond to the energy content of about 1 litre of heating oil. Pellets have a heating value (energy content) of approximately 5 kWh/kg.

Split logs are also increasingly used for heating in the last few years. Wood should be dry, ideally stored for 2 years, protected from rain water. Wood with water content between 15 and 20 % has an average energy value of 4 kWh/kg.

Wood chips are manufactured in various ways. For example, coniferous wood log pieces that occur in the sawmills and are not suitable for any other processing are crushed directly. They can be used as fuel for boilers in a size of 10 to 50 mm per piece.

Central heating with wood

Environmentally friendly and flexible, wood-based central heating systems are capable of supplying an entire house with heat throughout the year and can easily be combined with solar thermal systems.

Pellet boilers Central heating systems, which are operated with wood pellets are particularly convenient. During operation and maintenance, they are comparable to oil and gas heaters. Combination systems can also be loaded with other firewood such as wood chips or split logs. The pellets are kept in a storage room or tank and supplied to the boiler by means of either a suction or screw conveyor system. The systems are fully automated and can be modulated in a power range of 30 to 100 %.

Wood gasification boilers are used to burn split logs efficiently. The individual stages of wood combustion (wood gasification and wood gas combustion) occur separately. This local division – in conjunction with a sufficiently dimensioned heat exchanger surface area – ensures particularly low emissions, low flue gas temperatures and high boiler efficiency. An induced draft fan ensures the correct air supply. The secondary air supply is then responsible for complete combustion. The use of a sufficiently dimensioned buffer tank increases the ease of operation significantly.

Wood chip boilers work on the same principle as pellet boilers: The wood chips are transported automatically from a storage room into the boiler by means of a screw conveyor or similar device. An electronic control system regulates the combustion process and constantly optimises it. The output range of wood chip-fired central heating systems ranges from 30 kilowatts to several megawatts. This allows heating of apartment houses and entire business establishments.

Pellet boiler
Pellet boiler