Biomass
The main building of the Renewable Energy House is heated with wood pellets, one form of solid biomass. Wood pellets are a clean, CO2-neutral and convenient fuel, mostly produced from sawdust and wood shavings, compressed under high pressure using no glue or other additives. They are cylindrical in shape and usually 6-10 mm in diameter, and 10-30 mm in length. Furthermore, due to their high energy content, the convenient delivery and storage features, pellets are the ideal fuel for fully automatic heating systems.
With a rapidly growing share of the market, pellets are a key technology for increasing biomass utilisation in Europe and beyond. Pellets are also an excellent way of using local resources thus making a concrete contribution to environmental protection and climate change prevention.
Pellet heating systems have several particular advantages. As a condensed fuel, transportation is cheaper and less cumbersome than for other biomass fuels. The high degree of standardisation allows for extremely low-emission combustion, even in very small appliances. And wood pellets are a highly convenient fuel for end users: delivery by tank truck and automatic feeding systems make them as user-friendly and time-efficient as a gas or an oil heating system.
The pellet boiler and pellet transportation system was kindly provided by the Austria firm KWB.
The Renewable Energy House is equipped with an 80 kW pellet heating system and has two interconnected storage rooms which can take approximately 15 tonnes of pellets. The pellets are delivered by a tank truck (2-3 deliveries per year) and blown into the two rectangular storage rooms. From there and with the help of an elbow worm conveyer, they are transported automatically into the combustion chamber.
The boiler heating system is implemented as an underfeed firing system with afterburn ring. Ignition is carried out fully automatically. In the primary combustion area (burner plate), the fuel is fed in from underneath in a controlled way and, together with the slow primary-air flow, provides a smooth fuel bed, low dust emissions and optimum gasification conditions.
BIOMASS:
Biomass results from the process of photosynthesis. The energy from the sun is stored in the plants in a variety of forms (solid biomass, oil crops, sugar and starch plants, and wet biomass). The material can follow several conversion routes and can generate different final energy products such as heat, electricity and liquid biofuels. The output of the boiler can be adjusted to the heating requirements, in a fully automatic way, from stand-by to full-load operation. The pellet boiler is connected to the 5000 litre hot water storage tank and the boiler heats the main building of the Renewable Energy House. The pellet boiler is equipped with a fully automatic ash compaction unit. The ash is fully compressed so that it is only necessary to empty the ash box, depending on the boiler output, every 2 to 3 months. Ash contains pure minerals and is the perfect fertilizer for garden, lawn and forest.
Biomass Heating System equipment sponsor:
- KwB - pellet boiler and pellet transportation system
