Charcoal carbonization process

Although the charring stage is not the most expensive stage in the entire charcoal production process, it is decisive. If this work cannot be carried out effectively, the entire production process will be in a dangerous state, because with the consumption of bar and the increase in cost, the low output of the carbonization stage will inevitably lead to inefficiency of the entire production chain.

The core of the competition between carbon plants that are normally produced in the same area is carbonization technology. The same amount of salary rods are taken to different carbon plants for carbonization, and the quality and quantity of the final finished carbon are different because of the difference in carbonization technology level. Scientific and reasonable kiln body design, a good kiln burning method is the key to producing more charcoal. This directly affects the level of profitability of a carbon plant.

    Charcoal semi-finished products-the main components of the fuel rod include cellulose, wood fiber and water. Among them, cellulose and wood fiber and some other components are closely combined, which is why the mechanical strength of the salary rod is. Water is absorbed in the cellulose/wood fiber structure in the form of water molecules. The water content of the baton is generally below 9%.

This water will be dissipated in the form of water vapor before the effective carbonization process begins. The heat comes from the burning of a small number of fuel rods in the kiln. This is the so-called drying stage. Since the raw materials undergo strict drying treatment before being formed into salary rods, the drying stage in the carbonization process takes less time and requires less heat.

When the moisture content of the salary rod is close to zero, we need to continue to increase the temperature in the kiln. The heat required still comes from the burning of some of the rods in the kiln. When the temperature rises to 280 ° C, the sticks will spontaneously decompose, producing charcoal, methanol, acetic acid, and more complex chemicals. These chemicals often appear in the form of tar and non-condensable gases containing mainly hydrogen, carbon monoxide, and carbon dioxide. Because the air is allowed to enter the kiln, there is also a part of nitrogen from the air in the gas.

Only when the carbonized residue can be called charcoal, the carbonization and spontaneous decomposition will end. Unless more heat can be provided, the process will be terminated. At this time, the temperature reaches its maximum value of 400 ° C. However, this charcoal still contains an estimated amount of tar residues and native wood ash. The ash content of charcoal is about 3%-5%. Asphalt residue content is about 30%.

The rest is the so-called solid carbon, about 65%-70%. Further heating can increase the solid carbon content by removing and decomposing more tar. When the temperature reaches 500 ° C, the typical solid carbon content of 80% and volatile content of about 10% can be obtained. The charcoal extraction rate at this temperature is about 2.6: 1. The charcoal extraction rate will decrease with the increase of the final carbonization temperature.