Torrefied Wood Pellets is an Evolution for Biomass Fuel
TOR wood pellet, nowadays, is getting active in biomass fuel market because of its outstanding performance in industrial heating. With a black surface and higher energy density, it is likely called man made coal or bio coal. Then, what’s torrefied wood pellets and how’s it made?

wood pellets and torrefied wood pellets

What is torrefaction for biomass pellets making?
What makes torrefied wood pellets special is the raw materials that it’s made of. The raw materials for torrefied wood pellets is produced under torrefaction effect. Raw material is also the key difference between biomass wood pellets and the torrefied wood pellet. Processed by torrefaction effect, the raw materials are changed to obtain a much better fuel quality for combustion.

torrefication process

Torrefaction Process
Reaction conditions: normal atmospheric pressure; low oxygen condition; temperature 220℃ ~ 320℃; reaction time 20 ~ 30 minutes.
Reaction process: Step 1: As temperature rises up, the water contained in the biomass as well as superfluous volatiles are released.
Step 2: The biopolymers in biomass materials such as lignin, hemicellulose and cellulose partly decompose to give off various types of volatiles. The final torrefied biomass materials are solid, dry and blackened.

Parameter Comparing of Torrefied Wood Pellets with Wood Pellets and Coal

Species
Wood Pellets
Torrefied Wood Pellets
Coal
Moisture Content(wt%)
7.0-10.0
1.0-5.0
10.0-15.0
Volatiles(%db)
70-75
55-65
15-30
Calorific Value(GJ/t)
16-20
20-24
17-28
Bulk Density(t/m³)
550-750
700-850
800-850
Volumetric Energy Density(GJ/m³)
7.0-11.0
15-19
18-24
Ash(%)
1
1
9
Hard grove Grind ability Index
30
50
50

 

Superior Performance of Torrefied Wood Pellets
With a higher energy density, less water content, pure composition, torrefied wood pellet has a lot of advantages comparing with wood pellets and even coal.
1. With a higher energy density, torrefied wood pellets performs more efficiently than common wood pellets in power plant to replace coal.
2. With less water content, it is not easy to get damp, thus to save longer.
3. Torrefied wood pellet is a carbon neutral product. No polluting gases is be released during its burning.
4. After torrefied, biomass materials turn out to have a higher grindability index and they are easier to pelletize by biomass pellet mill.
5. More dense, the shipping cost of torrefied wood pellets is less than that of wood pellets.