Wood chips: “Green” efficiency at low cost

The wood chips are made of flakes of woody material of approx. 1-12 cm long and a few mm thick, obtained by the fragmentation of various types of wood with special machines called chippers.

Like other woody biomasses, it is a renewable source because the materials of waste represent the raw material for the growth of plant species of origin in a closed cycle on a global scale.

The possibility to chop wood of any shape, allows to obtain a low-cost fuel easily usable by automatic loading systems of modern Tatano wood chip boilers.

 

EN 14961-2: European standard

The main qualitative characteristics of wood chips for energy use, defined on the basis of the European standard EN 14961-4, are: the qualitative class, size, water content and ash.

Quality class according UNI EN 14961-4:

• Class A1 and A2
  Whole plants without roots, trunks, wood residues not chemically treated, cutting residues and limbing.
• Class B1
  Wood from forest, short cycle crops and other virgin wood, wood residues not chemically Treated
• Class B2
  By-products and residues from the first wood processing, post-consumption wood

The material previously used for other purposes (for example: pallets) is chipped for thermal use using grinders. The metal parts must be removed by magnetic separators.

Water content M according to UNI EN 14961-4

The water content (M = moisture) expressed in percentage terms is acceptable up to M35 (water content less than 35%), M25 is preferred for storage and greater yield.

 

Ash content According to UNI EN 14961-4

It is expressed in percentage terms referred to the dry mass. The following values are accepted for each qualitative class of wood chips:

• Class A1, characterized by an ash content A ˂ 1%.
• Class A2, characterized by an ash content A ˂ 1.5%.
• Class B1 and B2, characterized by an ash content A ˂ 3%.

 

Thermal Budget

• 1 m³ methane ≈ 3 Kg wood chips
• 1 Kg heating oil ≈ 3 Kg wood chips
• 1 Kg LPG ≈ 4 Kg wood chips