The composition and manufacture of wood pellets

Otherwise known as pellets, wood pellets are fuels used to heat a home. They are manufactured using a specific technique in order to have solid blocks ready for use. Several steps must therefore be followed to create wood pellets.

The pellet manufacturing process

Pellet production follows a standard, automated pattern. After the wood is collected, it is crushed in a sawdust silo. Then the crushed logs are dried by means of a biomass boiler or a pellet making machine. This can also be combined with a cogeneration plant to produce energy. The further steps are cyclone separator, fine screening, pellet production, cooling, screening, storage and final dust removal. Once the manufacturing steps are completed, the pellets are loaded in bulk into trucks. Noting that non-compliant fine particles may be added to the mixture as raw materials. Standards to be metIn order to guarantee optimal combustion, wood pellets must comply with certain standards. These standards relate to the way in which the pellets are manufactured. This is the European standard for wood heating EN 14961-2. These standards concern both the quantity and quality of the pellets. For example, care must be taken to ensure that the ash content is not too high in order to avoid wasting fuel. A large mass of ash can also damage the heater. In addition to the ash content, the fines content, fuel hardness and moisture content should also be checked.

Certifications

In addition to these standards, there are certifications, namely DIN and ENplus A1. These certifications also emphasize the conformity of the manufacturing process and the characteristics of the granules produced. The quality of the pellets must be below the European standard. Each producing plant is free to choose the standards for which it wishes to be certified. Noting that all certifications require the same requirement on the characteristics of the pellets. The difference lies mainly in the control entity and the way in which the certification is communicated. The NF standard, for example, qualifies pellets in three categories: high performance wood, standard wood and industrial quality wood. The latter is only dedicated to a particular use.