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.
Advantages of Bark as Raw Material for Making Wood Pellets
● 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
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.
|
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
|