What are the key steps in the production process of activated carbon?

There are several key steps in the production process of activated carbon, each of which has a significant impact on the performance and characteristics of the final product. The following are the key steps in the production of activated carbon:

1. Raw material selection:

-Choosing suitable carbon containing materials is the first step in producing high-quality activated carbon. Common raw materials include wood, coal, coconut shells, and fruit kernels. Different raw materials can affect the pore structure and adsorption characteristics of activated carbon.

2. Carbonization:

-Carbonization refers to heating raw materials to high temperatures (usually between 400-700 degrees Celsius) under anaerobic conditions. This process removes moisture and volatile substances from the raw materials, leaving behind carbonized materials mainly composed of carbon.

3. Activation:

-Activation is the process of heating the carbonized material to a higher temperature (usually between 800-1000 degrees Celsius) while introducing oxidizing gases such as water vapor, carbon dioxide, or air. This process forms a large number of micropores in the carbonized material, greatly increasing its specific surface area and adsorption capacity.

-Activation can be divided into physical activation and chemical activation. Physical activation uses gases such as water vapor or carbon dioxide, while chemical activation involves the use of chemical agents such as zinc chloride or phosphoric acid.

4. Cooling and washing:

-Activated carbon needs to be rapidly cooled to maintain its pore structure after activation. Next, remove residual chemicals and ash by washing to ensure the purity of the product.

5. Drying and molding:

-The washed activated carbon needs to be dried to remove moisture. According to the end use, activated carbon can be compressed into different shapes, such as powder, particles, columns, or blocks.

6. Screening and packaging:

-Dried activated carbon is usually sieved to ensure uniformity in particle size. Finally, activated carbon is packaged for storage and transportation.

The specific conditions and operations of each step will affect the final characteristics of activated carbon, including its pore structure, adsorption capacity, and mechanical strength. Therefore, precise control of these steps is crucial for producing high-performance activated carbon.