Bark is part of the timber and trees; it needs to be debarked when the timber is wanted to be used to make other things. But the bark can be used to make biomass fuel pellets for heating.

Harnessing bark from forest residues for fuel pellets is gaining attention. Research confirms the viability of bark pellet machines in pelletizing bark. Remarkably, bark, being more affordable than wood, yields pellets with comparable heating values.

The bark pellet machine is a device that physically presses sawdust, wood powder, branches, bark, pine bark, etc. into new biomass energy fuel pellets after crushing (optional). This biomass pellet machine effectively solves the problem that coarse fibers such as bark, shavings, and sawdust are difficult to pelletize and have poor effects. No adhesive is added, and only the fiber’s own adhesion is used to wrap and form. The pellet fuel after forming is firm and smooth, easy to burn, high in calorific value, smoke-free and pollution-free, and high in density for easy transportation. It effectively handles solid waste materials to achieve waste recycling and reuse in scenes such as logging sites, woodworking factories, and forest farms.

Before the formal pelletization, the bark pellet machine needs to process larger materials into small particles or sawdust with a chipper or crusher, and the raw materials with a humidity of more than 20% need to be dehumidified and dried with a dryer.

Wood powder, sawdust, etc. that meet the requirements of humidity and particle size enter the bark pellet machine through the feed port, are pressed into a solid state under the action of two rotating rollers, and are squeezed out of the outer die pores to form.

After being pressed into shape by the bark pellet machine, the volume of the pellets is only 10-13% of the raw material, the density can reach 0.8-1.5, and the calorific value during combustion can reach 3500-6000 kcal depending on the raw material.

1. Home and small heating systems

Bark pellet fuel can be directly used in home fireplaces, small heating stoves or micro boilers to provide a stable heat source. Its combustion efficiency exceeds 80%, and its sulfur content is low (<0.03%), which significantly reduces sulfur dioxide and dust emissions and is suitable for indoor heating.

2. Industrial boiler fuel

Bark pellets can replace traditional fuels such as coal and natural gas, and are used in steam boilers in industries such as textiles and food processing. The combustion calorific value reaches 4200-5500 kcal/kg, which is close to 80%-90% of standard coal, and the operating cost is reduced by 40%-50%.

3. Biomass power plant

Bark pellets are used as fuel in power plants, and electricity is generated through special combustion furnaces or gasification devices to achieve efficient utilization of renewable energy. Ashes can also be used as potash fertilizer resources.

1. The raw material source is wide and renewable

Bark is a byproduct of wood processing (such as sawdust, branches, bark, etc.), which belongs to agricultural and forestry waste. Using bark to produce pellet fuel can reduce waste accumulation, while complying with the concept of sustainable development and avoiding excessive felling of native trees.

2. Low carbon and environmental protection, reducing pollution

Bark pellet fuel has low carbon emissions when burned, and does not contain harmful substances such as sulfides. After burning, the ashes can be directly returned to the field as potash fertilizer, forming a resource cycle. Compared with coal, its combustion efficiency is higher (up to 83%), and the emissions of sulfur dioxide and nitrogen oxides are significantly reduced.

3. Improve combustion performance

After high-temperature compression, the density and calorific value of bark are greatly improved (calorific value can reach 4300-5500 kcal/kg), and the combustion duration is longer, which is suitable for industrial boilers, home heating and other scenarios. Its low moisture content (8%-10%) is also convenient for storage and transportation.

4. Economic advantages

As a waste material, bark has low raw material acquisition cost. After processing, it can replace traditional fuel and reduce corporate energy expenses.
By pressing with a pellet machine, bark is converted into high-density fuel, and its volume is reduced to 1/15 of the original wood, which greatly reduces transportation and storage costs.