Wood Pellets Manufacturing

Wood pellets are made by taking wood that has been broken down into small pieces and compressing it into a pellet. The material is compressed by pressing it into a die which is a hole the same diameter as the desired pellet with a funnel shaped top. As the material is pressed deeper into the die it gets compressed as the diameter of the hole decreases.

As the wood compresses it generates heat which melts the lignins in the wood. Lignins are compounds that will act as a binder or glue after the finished pellet cools. Many materials like softwoods naturally contain enough lignins but some other materials may need additional binders like vegetable oil to be added before they are pelletized.

Learn more details about how wood pellets are made.

The two main components of a pellet mill are a roller and a die. A die is a piece of metal that is full of the holes that the pellets are formed in. The roller rolls across the surface of the die and presses the raw material into the die. As the material is continuously fed into the die the finished pellets are extruded out the other end.

The two common types of mills are flat die and ring die. A flat die mill has a die with a flat surface that the raw material is spread out on top of and the roller rolls across the top. With a ring die mill the die is a ring shape and the roller or rollers roll around the inside surface of the ring where the opening of the holes are. The pellets are extruded out of the outside surface of the die.

Learn more about wood pellet mills.

The pellet mill is the heart of the pellet manufacturing process but in order to make consistent quality pellets there are other components to a pellet mill.

A drier is needed to reduce the moisture content to 10-20% depending on the material. This is the most energy intensive of the process and is often fueled by pellets.

A mixer will mix the raw material to ensure consistency. This is especially important if binding agents will be added.

Material handling will be needed in large commercial pellet mills. For raw material augers, vacuum and conveyor belts are commonly used. For finished pellets elevator buckets are used since they are less likely to damage the pellets.

A screener separates small fragments and dust from the finished pellets.

Bagging or other storage equipment will put the pellets in bags or other containers that will protect the finished pellets from absorbing moisture.

Learn more about wood pellet manufacturing equipment.

As people are looking more toward green renewable sources of energy, wood pellets are being looked at as an affordable and practical alternative to fossil fuels.

Wood pellets have had challenges in the past with availability in some areas. At times existing pellet producers and distributors have not been able to keep up with demand. As more mills are investing into pellet production supplies are becoming more reliable. Wood product manufacturers are discovering that wood pellets can provide a steady income since it's a consumable product that people buy even when other forest products like lumber and paper are in low demand.

With an increase in forest enhancement projects like fuels reduction and thinning on both private and government forest land there are more possibilities for sources of raw material. In the near future carbon credit funds may contribute to an additional increase in forest enhancement projects that can produce materials for making pellets.

Learn more about wood pellets and wood pellet production.