Company Blog 2025-07-07

How Does A Biomass Pellet Mill Work?

2025-07-07Charcoal Making Machine

Back to Article
List

Biomass pellets, as a new type of fuel with low carbon and high calorific value, are favoured by many industry sectors, such as rural heating, industrial boilers and export trade. Biomass pellet mill machines make raw materials such as wood chips into high-density pellet fuel through high-pressure extrusion. So? How does a biomass pellet mill machine work? Today VICTOR MACHINERY will share with you.

Raw Material Crushing

In the process of making biomass pellets, raw material crushing is the first step. The raw material is finely crushed to a small enough size to fit smoothly into the biomass pellet machine mould. If the raw material is large, it needs to be crushed by a crusher first. If the raw material is small enough, e.g. sawdust, wood chips, etc., the crushing step is not necessary.

Raw Material Drying

After the raw material has been crushed, it needs to be conveyed to the dryer for subsequent processing. Drying of the raw material is essential prior to pelletising. The moisture content of the raw material needs to be controlled between 10-12 per cent. This ensures that the pelletising process runs smoothly. The right amount of moisture is a key factor in making high quality pellets. Heating and drying is a costly part of the pelletising process and ensures pellet yield and quality.

Compression Moulding

The raw material is fed to the compression type through a conveyor. The raw material is subjected to strong compression forces. The raw material is compressed under high pressure into strips or other shapes. During this process, the bonding between the raw material particles is greatly increased and a certain strength is formed.

High Temperature Treatment

The biomass pellet mill also needs to enter a continuous carbonisation furnace for high temperature carbonisation, in which pyrolysis and polymerisation of lignin and other components in the raw material take place in a high temperature environment. High temperature treatment can provide the calorific value and corrosion resistance of biomass pellets to reduce humidity to improve combustion efficiency. High temperature treatment is to allow the raw material to further solidify to form pellets.

Cooling And Moulding

Pellets after high temperature treatment have a high temperature and need to be cooled down by a cooling system. This is usually done by natural air drying or with the help of a cooling system. Cooling prevents the pellets from overheating and burning. The cooled pellets are extruded into a solid fuel pellet by the action of a die and an extruder plate. The pellets are usually moulded in a regular shape, which can be customised to meet customer requirements.

Discharge Packaging

The moulded pellets are discharged from the pellet mill through the discharge opening to become the final biomass pellet fuel product. The product is packaged in a packaging system for easy transport and storage. To ensure the quality of biomass pellets, the storage environment must be far away from humidity, ventilated and dry.