Wood pellets represent cylinders of 6-8 mm diameter, manufactured from ground and dried wood by means of pressing with the use of high pressure, not containing any artificial adhesives (sometimes 1% of starch is added).

Standard pellets have the following characteristics:
Density – 1200-1400 kg/ cu m, i.e. fuel pellets drown in water.
Humidity – 8-12%.
Calorific capacity – about 4200 kcal/kg = 17600 kJ/kg = 4.9 kWh/kg.
Ash-contents 0,5-2%.

What are pellets made of
Usually waste from woodworking: chips, shavings, rough edge, shreds and the like, is used a raw material for pellets. Debris like: undersized trees and woodfuel, spires, trim ends, branches, crooked trunks and the like are also used in pellets production.

One can also use agricultural waste in pellets production for industrial boilers: straw, shove and peat. Pellets made from silver grass – tall-growing grass with ash-content about 3% are already used in private house of Western Europe. However, we would like to draw your attention to the fact that such pellets are noted for greater ash-content (for example, sunflower husk – about 7%, peat – from 2 up to 15%), than wood pellets and their use for small pellet boilers is undesirable.

Pellets and ecology
Wood pellets are becoming more and more popular with every day both on the West, and in Russia. Ecological “friendliness” of pellets plays not the least role in that:

• Upon pellets combustion less than 1 percent of ash is generated, which could be used as fertilizer.
• Upon combustion of wood pellets minimum quantity of emissions of harmful substances into the atmosphere is generated, compared to coal, diesel fuel and mazut.
• Pellets do not require special conditions for storage. They are completely chemically and biologically safe.
• Wood pellets are manufactured from renewable raw materials and help making many productions non-waste.
• Due to their density and low humidity pellets possess higher energy density compared to common woodfuel.