How can the quality of finished products be improved by using wood shavings briquette maker?

Jan 19, 2026

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After briquetting, the wood chips need precise carbonization to be transformed into high-quality charcoal. The key is controlling the temperature, heating rate, holding time, and oxygen content of the biomass briquette press, forming a complete process of "low-temperature drying, medium-temperature pyrolysis, and high-temperature carbonization," which is completely different from the post-processing of wood pellet mills, which only requires cooling and screening. Temperature control is crucial and requires precise control in stages: In the drying stage, the temperature is raised from room temperature to 100-200℃ and maintained for 1-2 hours to remove 8%-12% of the residual moisture from the wood chips. The heating rate can be slightly faster in this stage (50-80℃ per hour), but it is necessary to avoid localized overheating that could cause the surface of the wood chips to dry out and prevent internal moisture from being released.

During the pyrolysis stage, the temperature rises to 200-400℃. This is the critical period for the release of volatile matter (accounting for 60%-70% of the raw material weight, including methane, ethane, and tar) from the sawdust. The heating rate needs to be slowed to 30-50℃ per hour, and volatile matter must be promptly removed to prevent its accumulation in the carbonization furnace, which could lead to combustion or explosion. If the temperature rises too quickly, the rapid release of volatile matter will create numerous pores within the charcoal, reducing its strength; if the temperature rises too slowly, it will prolong the production cycle and increase energy costs. During this stage, the furnace pressure must be closely monitored and maintained at a slightly negative pressure to promote the removal of volatile matter.

In the carbonization stage, the temperature rises to 400-600℃ and is maintained at a constant temperature for 2-4 hours. This allows the cellulose and hemicellulose in the sawdust to be fully converted into fixed carbon. The higher the temperature at this stage, the higher the fixed carbon content and the higher the calorific value of the charcoal. However, temperatures exceeding 600℃ will increase the brittleness of the charcoal, making it more prone to breakage. The holding time needs to be adjusted according to the size of the sawdust blocks; the larger the diameter and the longer the length, the longer the holding time should be to ensure thorough internal carbonization and avoid a "burnt outside, raw inside" situation. Compared to producing pellet fuel using a wood pellet machine, the carbonization process requires additional investment in a carbonization furnace, resulting in higher energy consumption and technical barriers, but also significantly increased added value of the finished product.

After carbonization, cooling is necessary. The heat source should be turned off, the carbonization furnace sealed, and the charcoal allowed to cool naturally to room temperature (approximately 8-12 hours). Opening the furnace door during cooling is strictly prohibited to prevent air from entering and causing charcoal combustion loss. After cooling, the charcoal is removed, surface impurities and debris are removed, and it is screened and graded. Charcoal with a carbon content of 70% or higher is considered high-quality charcoal and can be used in high-end applications such as barbecues, metallurgy, and chemicals. Lower-quality charcoal can be pulverized and used as a fuel additive to improve resource utilization.