Bark, the substantial component in forest harvesting residues, emerges as a new raw material source for fuel pellets making. The research shows that it is feasible to use bark pellet machine to make fuel pellets from barks. Furthermore, bark is much cheaper than wood, while bark pellets can supply with the similar heating value as wood pellets.

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Advantages of Bark as Raw Material for Making Wood Pellets

● Bark has good binding characteristics, so it has high mechanical strength.
● Bark has high calorific value due to high carbon content and low hydrogen content.

Chemical composition of bark from two common species

Species
Cellulose
Hemi-cellulose
Lignin
Extractives
Ash
Pine (70 years old)
Bark, inner
36
26
29
5
4
Bark, outer
25
20
48
3
4
Spruce (110 years old)
Bark
36
20
36
4
4

Calorific value of wood component

Wood component
Calorific value (GJ/metric ton)
Cellulose
17-18
Hemi-cellulose
16-17
Lignin
25-26
Extractives
33-38

 

 Calorific value and bulk density of bark from two common species

Species
Calorific value ( GJ/ton)
Density (kg/m3)
Pine
18.4-20.7
300
Spruce
17.8-19.8
340

 

 

Preparation of Barks for Making Bark Pellets at Home

Bark pellet machine has requirements for feedstock on the size and moisture content. You can use a hammer mill to grind barks into the size of less than 6mm. Because home production volume is small, so considering to reduce cost, you can dry the ground barks under the sun rather than by using drying machine

preparation_of_bark_for_making_fuel_pellets

Bark Pellet Machine for Home Use

When the preparation of barks is completed, put the feedstock into AZSP-150D bark pellet machine directly to make your own fuel pellets at home right now. AZSP-150D bark pellet machine is powered by diesel engine and designed without unnecessary wires; it is easier to move to the open air and to the place where there is no electricity. It is more convenient than electric pellet mill.

 bark_pellets_machine Model: AZSP-150D

Power: 8HP

Capacity: 50-90kg/h 

Engine: Diesel engine

Packing size: 870*440*730mm

Calorific Value of Bark Pellets (on dry basis)

Chemical component
Measurement
Bark pellets
Gross calorific value
J/g
21,770.9
Hydrogen
% of weight
5.9
Nitrogen
% of weight
0.3
Oxygen
% of weight
38.88
Sulphur
% of weight
0.22
Carbon
% of weight
52.5
Total moisture content
% of weight
5.73
Total ash
% of weight
2.00