What Is The Carbonisation Process?

Charcoal carbonization is a high-temperature carbonization heat treatment process conducted under oxygen-deprived conditions. During this process, natural resins, moisture, and flammable gases within the wood are fully volatilised. The lignin in the wood is converted into charcoal. Charcoal has the characteristics of a low ignition point, high calorific value, and long burning time. It is an excellent fuel. The carbonization furnace is a crucial piece of equipment in the carbonization process. Carbonization furnaces can be categorised into three types: continuous carbonization furnaces, suspended furnaces, and horizontal carbonization furnaces.

During the carbonization process, wood undergoes four distinct stages.

Drying Stage

During this stage, the heating temperature is maintained between 150-200°C. The primary purpose of the drying stage is to evaporate the moisture from the wood. During this process, the wood's primary chemical components remain unchanged.

Pre-carbonization Stage

When the furnace temperature reaches 200-275°C, the wood enters the pre-carbonization stage. During this period, unstable components of the wood, such as hemicellulose, begin to decompose, producing carbon monoxide (CO) and small amounts of acetic acid.

Carbonization Stage

When the carbonization temperature reaches 300-400°C, the wood enters the carbonization stage. At this point, thermal decomposition reactions occur. During this process, cellulose and lignin decompose sequentially. Simultaneously, large amounts of acetic acid, tar, methanol, carbon dioxide, and flammable gases are produced. At 275–300°C, wood vinegar and flammable gases reach their peak production. Within the 300–400°C range, wood vinegar gradually decreases. A large amount of flammable gases are emitted. When the temperature reaches 400–450°C, the carbonization process effectively comes to an end.

Calcination stage

When the carbonization temperature reaches 400–450°C, the wood enters the calcination stage. In this stage, external heat is required to further promote the volatilisation of residual volatile components in the charcoal.

It is important to note that due to differences in wood species, the temperatures for thermal decomposition carbonization may vary. There are no clear boundaries between each stage. Within the carbonization furnace, temperatures may also differ between stages. Different parts of the wood may be at different stages of carbonization. In a continuous carbonization furnace, the same type of wood may undergo different stages of carbonization simultaneously.

If you would like more detailed information about the wood carbonization process, please feel free to contact us. We will provide customised charcoal production solutions based on your raw materials.

• Perv: What Is The Process of Carbonization Of Coconut Chells?
• Newxt: Back To List