Wood pellets production is a profitable business. But to properly organize it, you need to consider a lot of nuances: from choosing a future consumer to acquiring all the necessary equipment.
Pellets or they are also called wood fuel pellets, are waste from wood processing: sawdust and shavings from trees. Nowadays startups are investing in wood pellet mill businesses and generating ample amount of revenue. They are formed under the high pressure of three hundred atmospheres without the use of glue or additives. The resulting granules are ten to thirty millimeters long and six to ten millimeters in diameter. The calorific value of such pellets is within five kilowatts per hour, approximately comparable to coal.
How much energy you can get from these wood pellets?
By burning one ton of pellets, the energy released is comparable to burning:
- Five hundred liters of diesel fuel.
- Seven hundred liters of fuel oil.
Fuel pellets have a better effect on the environment, compared with the above fuel.
Lighting them up:
- Carbon dioxide emissions are reduced ten to fifty times.
- Ash is formed ten to twenty times less.
- Practically no sulfur is formed.
In general, such fuel is intended for:
- Heating of private houses. Where boilers and fireplaces are installed.
- Use in boiler houses of housing and communal services.
- For combined heat and power (CHP) systems.
- As a filler for cats’ toilets.
- In this case they can localize and remove the liquid.
What are wooden pellets made of?
Granules are made only from wood, or wood with bark is used. Both varieties are in demand in the market. Pellets, where the bark content is less than half a percent, practically do not form ash. They are considered high-quality and ecological products. Often used for private buyers.
Pellets for industry contain up to ten percent bark. They are used in large and medium-sized thermal installations.
The feedstock for them: wood shavings or other woodworking waste (low-value trees, etc.). Such a product is created only where there is a lot of wood waste in the constant presence. The sawmill and the production of pellets are ideally combined. These companies operate around the clock throughout the year.
Technological characteristics of the raw materials used:
- Moisture content of raw materials should not be higher than twelve percent.
- Fraction of raw materials from one and a half to five millimeters.
Wooden Pellet production technology
The classic manufacturing process looks like this:
- Crushing into large parts.
- Second crushing into small parts.
- Mixing and water treatment.
- Cooling and drying.
During the first crushing, the wood is crushed for further drying. The crushed raw materials should reach a size of no more than 25 millimeters in length and width, and two millimeters in thickness. This will make drying high-quality and fast, as well as dry the materials and prepare for the second crushing.
If the humidity exceeds 15%, it is harder to press. In addition, the increased humidity of the pellets makes them unsuitable for boilers. Therefore, the raw material must be dried before the press to such an extent that its moisture content is eight to twelve percent. The final humidity should be in the region of 10% plus or minus one percent. In all production, drying takes the most energy. To dry one ton of pellets, the heat of combustion from one cubic meter of dense wood is needed. The best would be to burn the bark.
Water treatment is the establishment of the desired level of moisture in the raw material. If its humidity does not exceed eight percent, the pellets stick together worse in the press. For this purpose, a dosage of moisture in the mixing container is needed. If hardwoods are being processed, such as oak or beech, hot steam must be added.