What is the influence of the source material on the application possibilities of activated carbon?

The precursor or source material from which activated carbon is produced largely determines the porosity, pore size distribution, mechanical strength, ash content and also the adsorption behaviour of the type of activated carbon. Although the manner in which the carbon is activated is obviously also essential, the precursor sets the fundamental limits of what is technically feasible.

Each source material has a unique chemical composition, density and structure. These properties influence, among other things, how the material will deform during the activation process, how steam (or chemicals) can develop pores, as well as the robustness and stability of the activated carbon in industrial applications.

Bituminous coal (coal):

• Pore size distribution: good balance between micro- and mesopores
• Advantage: very versatile, suitable for gas and water applications
• Critical point: higher ash content can be problematic for ultra-pure applications

Anthracite (coal):

• Pore size distribution: very dense and microporous structure, requiring more aggressive activation
• Advantage: very resistant to abrasion and low dust content
• Critical point: often requires more intensive steam activation compared to other source materials, which has an impact on price

Coconut shells (biobased):

• Pore size distribution: strongly microporous, ideal for purifying gases and capturing small molecules
• Advantage: very high hardness and low dust content
• Critical point: due to the small pores, coconut carbon is less suitable for large molecules in liquids

Wood (biobased):

• Pore size distribution: more mesopores compared to coconut, bitumen and anthracite, depending on wood species and activation conditions
• Advantage: suitable for removing large molecules
• Critical point: mechanical strength can be a limitation in applications with high flow rates or for reactivation

A large specific surface area is therefore not sufficient. Without the correct pore size distribution and mechanical properties, the carbon will not perform optimally in the chosen application.

At Cargen, we analyse the type of carbon and the chosen source material based on:

• Purification application: gas vs. liquid and molecular size of the contaminants to be captured
• Required pore structure: micro vs. meso or a combination
• Mechanical requirements: hardness, possibility of reactivation
• Ecological and economic factors: origin, ash content, sustainability

This way we offer a solution that works both technically and practically.

The choice of source material is decisive for the performance of the activated carbon in the specific application. Each material has unique advantages and disadvantages, meaning that a targeted selection based on application, pore size distribution and mechanical properties is essential for optimal adsorption and effectiveness.