Properties of wood pellets

Main physical properties of sawdust pellets

This is an annex of our pellets file.

A) General Properties

- Raw material: sawdust from untreated wood.
- Lower Calorific Value, PCI: between 4,5 and 5 kWh / kg.
- Density of the pellet alone: ​​1100 to 1300 kg / m3 (the pellet sinks in the water!)
- Bulk density: from 600 to 750 kg / m3, or approximately half the density of the granule (50% dead volume).
- Energy equivalence to fuel oil: 2kg of pellets = 1 Liter of fuel oil
- Energy equivalence to town gas: 2 kg of wood pellets = 1 m3 of gas.
- Storage: equivalent in bulk volume necessary compared to fuel oil: 3,5 times the volume of fuel oil, 1000L of fuel oil therefore require 3,5 m3 of pellet storage (safety included).
- Indicative price for 1 tonne in bulk delivered in 2007 in France: around € 200 including tax.

B) properties in detail and standards

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Depending on the use (industrial or individual installation) the standards of wood pellets vary slightly. This is mainly due to a greater tolerance to the fuel of industrial units!

In other words: a 10kW pellet stove operating intermittently is more sensitive to the quality of the fuel than a 500kW burner operating continuously!

At the moment (end of 2007) only Germany and Austria have national standards.

Other European countries are in the process of setting a European standard CEN / TS 14961, which is more or less in line with German standards (DIN) or autrichiene (ÖNORM).

The CEN / TS 14961 provides the following general requirements:

a) For pellets intended for individuals

- Origin: wood not chemically treated.
- Humidity: M08 (<8% relative).
- Durability: DU97,5 (which means that after sieving, see "Find out more", 97,5% or more of the pellets must remain intact).
- Diameter: D06 or D08 (6 or 8 mm).
- Length: <4 or 5 times the diameter, i.e. 30 mm maximum for D06.
- Ash content: <A0,5 (<0,5% volume)
- Sulfur: <S0,02
- Nitrogen: <N0,3
- Close: <Cl0,01
- PCI:> = Q16.9 (i.e. 16.9 MJ / kg or 4,69 kWh / kg)
- Bulk density MMV: BD650 (> 650 kg / m3)

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b) For pellets for industrial means

- Origin: wood not chemically treated.
- Humidity: M10
- Durability: DU96,5
- Diameter: D06 or D08
- Length: <4 or 5 times the diameter.
- Ash content: <A1,0
- Sulfur: <S0,05
- Nitrogen: <N0,3
- Close: <Cl0,01
- PCI:> = Q16.9
- Bulk density MMV: BD600

More: CEN TS 14961 and properties of pellets in Europe

1 comment on “Properties of wood pellets”

  1. If you want to see more on sawdust pellets, I invite you to read the stone article:
    the eco-friendly and economical firewood par excellence
    Thanks for giving your opinion

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