The working principle of an activated carbon making machine involves several complex and interrelated processes.
Firstly, the raw materials, such as coconut shells, coal, or wood, are fed into the machine. These raw materials undergo a pre-treatment stage where they are crushed into smaller pieces to increase the surface area and facilitate subsequent processes.
Next is the carbonization process. The crushed materials are heated in an oxygen-limited environment at high temperatures. This causes the decomposition of organic compounds within the materials, converting them into carbon-rich char.
The char then undergoes the activation stage, which is a crucial step. There are two common activation methods: physical activation and chemical activation. In physical activation, steam or carbon dioxide is passed over the heated char at high temperatures. This causes the development of pores within the carbon structure, increasing its surface area and adsorption capacity. Chemical activation, on the other hand, involves impregnating the char with chemical agents like phosphoric acid or zinc chloride before heating. These chemicals help in creating a porous structure.
After activation, the resulting activated carbon undergoes a series of post-treatment processes. This may include cooling, washing to remove any remaining chemicals or impurities, and drying to achieve the desired moisture content.