Overview of charcoal and activated carbon

Overview of charcoal and activated carbon

Charcoal

Charcoal is considered to be a metamorphic form of graphitic carbon that is produced as a residue when carbon-rich materials are partially burned or burned in the absence of oxygen. Carbon-rich materials include mainly materials such as wood.

One thing to note is that charcoal is not naturally occurring in nature. That is, it is a man-made product. Even if charcoal is found in nature, it is likely to have been produced due to the effects of high temperatures such as forest fires.

Activated carbon

Activated carbon is a carbon-rich solid that is extracted by pyrolysis from biomass or other carbon-containing materials such as coal or tar pitch. In this process, the carbon material is also "activated" through a process that greatly increases the surface area of the material, allowing it to trap (or "adsorb") more molecules. This high adsorption capacity allows activated carbon to effectively remove pollutants from water and air, which is why it is often used in remediation or purification projects.

What do charcoal and activated carbon have in common?

Production of carbon rich solids through pyrolysis

Both charcoal and activated carbon are made through a process called pyrolysis, in which a raw material - in this case, a carbon-containing substance - is subjected to high temperatures in the absence of oxygen, causing it to thermally decompose into char, or carbon-rich solids. The lack of oxygen is key to the process, as too much carbon dioxide is introduced and caused to burn off as a gaseous product. In pyrolysis, the starting material (or "feedstock") and processing conditions can be adjusted to tailor the carbon-based product to the specific application.

The quality of the feedstock can also affect its processing efficiency, end application, and possible environmental impact. For example, other biomass sources may include unknown biomass and materials collected from municipal waste streams.

Processing conditions include pyrolysis temperature and duration, particle size, moisture content, and activation -- improving the effectiveness of carbon materials by increasing their porosity and surface area.

Activation is typically accomplished by one of two processes.

The physical process includes steam activation, in which steam is introduced to remove carbon from an already charred (or "carbonized") material at a higher temperature. This process opens the pores of the carbon to increase its surface area.

The chemical process involves mixing raw materials such as wood with chemicals such as phosphoric acid, and then drying and carbonizing them. This chemical prevents the resulting carbon from shrinking, resulting in a structure with higher porosity.

Chemical Composition

Charcoal and activated carbon are also similar on a chemical level. Each solid contains a number of "aromatic carbons" that are tightly bound together, making them stable.

Carbon-rich materials can also contain elements such as oxygen or nitrogen, which were once part of the source material, or other chemicals, if the solids have been "loaded" with ingredients that enhance their effectiveness in a particular application.

The main differences between charcoal and activated carbon

1. Charcoal is produced by partially burning wood and carbon matter, or burning in the absence of oxygen. In contrast, activated charcoal is obtained by burning carbon-rich materials and adding other substances such as acids, bases or salts.

2. Charcoal burns at a lower temperature compared to the heat required to burn activated charcoal. The substances added to activated charcoal are the reason why such a large amount of heat is required.

3. Charcoal has a smaller overall surface compared to activated carbon and is a poor material absorber.

4. Charcoal is also less porous than activated charcoal.

5. Charcoal is used in places such as cooking products and pharmaceuticals, while activated charcoal is used in skin care products, deodorants and water filtration.

Activated carbon also has better properties compared to charcoal, such as a larger total surface area making it a good absorber. Activated carbon also has higher porosity compared to charcoal. If you need activated carbon, please feel free to contact us and we will provide you with the best service.