What is activated carbon?

activated carbon

Activated carbon, sometimes known as active carbon or activated charcoal, is a versatile and powerful material that plays a crucial role in purification and filtration processes across many applications.

Over recent years, the popularity of activated carbon has soared particularly in various industries where environmental regulations are stringent.

The RBH Group is partnered with Donau Carbon to supply powdered, granular and extruded grades of activated carbon to the UK, Ireland and Benelux. We specialise in providing technical support and advice to businesses whose successful operations rely on advanced materials such as activated carbon. 

Let’s take a look into the world of activated carbon and why you should consider using it in your applications.

Activated carbon: What is it?

Activated carbon is a highly porous form of carbon which is manufactured from a variety of raw materials including coal, as well as material from renewable sources and waste products such as bamboo, coir, wood and coconut shells. It’s processed to have small, high-volume pores that increase its surface area, thereby enhancing its adsorption capabilities. 

The term “activated” refers to the treatment or “activation” that imparts high surface area and porosity to the carbon. This activation process involves chemical or physical methods, such as steam activation or chemical activation with acids and bases.

Activated carbon’s porous characteristics make it incredibly effective at trapping impurities present in liquids and gases, making it one of the most widely used purifying agents across various industries for decades. Pore size will vary depending on the activation process and these can be impregnated with a wide range of materials that will aid in the adsorption process, allowing the targeting of a wide range of contaminants.

raw activated carbon

How activated carbon works

To understand how activated carbon works, we first need to cover its key process – adsorption. This differs from the commonly used term absorption.

Where absorption involves soaking up a liquid into another substance, adsorption refers to the adhesion of particles onto the surface of the substance. For example, a sponge soaking up water is absorption, but water molecules clinging to a glass window is adsorption. The key difference is that adsorption is a surface-based process.

Activated carbon relies on van der Waals forces, which are attractive forces between molecules. These forces facilitate the adherence of molecules to the surface of the carbon. The greater the surface area, the more van der Waals forces come into play, enhancing the adsorption capacity.

It’s worth noting that the activated carbon we offer is tailored for selective adsorption, so it can easily remove target pollutants whilst leaving other substances unaffected. 

adsorption vs absorption

Forms of activated carbon

Activated carbon isn’t one single product, in fact, there are many different grades and physical forms available all designed with different properties to serve different purposes.

The most common physical forms of activated carbon include:

Powdered activated carbon (PAC)

Consisting of finely crushed or ground particles, powdered activated carbon is predominantly used in liquid-phase applications due to its increased surface area providing effective adsorption properties.

Granular activated carbon (GAC)

Comprising of larger particles compared to PAC, granular activated carbon is produced as granules or irregularly shaped pieces. Despite the larger particles, granular activated carbon typically has a smaller specific surface area compared to other physical forms. 

Widely used in both liquid and gas phase applications, GAC is often a cost-effective alternative to extruded activated carbon and is easier to handle than powdered activated carbon.

Extruded activated carbon (EAC)

Produced by pulverising activated coal or charcoal and mixing with a suitable binding agent, extruded activated carbon is then formed into cylindrical pellets or tubes. It’s typically used in air and gas purification systems due to its mechanical strength, low dust generation and optimal gas flow characteristics.

extruded activated carbon

Selection of activated carbon grades

Understanding the differences between the grades of activated carbon available is crucial because different grades have different characteristics which make them suitable for specific applications. The effectiveness of activated carbon depends on many factors such as particle size, surface area, mechanical strength and impregnation.

All of the above can result in huge differences in performance and effectiveness. The RBH team are on hand to help you select the best grade for your specific process, get in touch with us for further assistance.

Key applications

Some of the most common uses of activated carbons include:

Water treatment

Activated carbon excels at adsorbing potentially toxic impurities from water, ultimately making the water safe to drink as well as improving its taste and odour. 

We can supply HYDRAFFIN® for water treatment applications, ideal for filtering and purifying drinking water, swimming pool water, waste water and much more.

Air and gas treatment

Industries use activated carbon to remove impurities and contaminants from gas streams. These can include odours, volatile organic compounds (VOCs) and harmful gases from indoor air as well as impurities commonly found in industry such as hydrogen sulphide and chlorine-containing gases. Applications such as flue gas cleaning, solvent recovery, and natural gas purification commonly use activated carbon.

We can supply DESOREX® and SUPERSORBON® as a suitable solution for various air and gas purification applications.

Liquids treatment

Activated carbon is widely used for the treatment of liquids particularly in the food & beverage industry. It’s highly effective in removing dissolved organic compounds, unwanted colour, and controlling the odour and taste of products such as wine, beer, fruit juice, vegetable oils and more.

We can supply CARBOPAL® & EPIBON® for use in a range of liquid treatment methods.

Special applications

For applications where more specialised chemical grades of activated carbon are required, we offer the ALCARBON® range which is produced with different properties to be used in a wide range of special applications.

activated carbon air purifier filter

Why should you use activated carbon?

We’ve covered the ins and outs of what activated carbon is and how it impacts different industries, but how do you know if it’s the right choice for your application?

Let’s recap some of its advantages:

  • Exceptional adsorption properties: Activated carbon’s high surface area and porosity make it an excellent adsorbent, effectively capturing and holding a wide range of impurities and contaminants
  • Versatility: It is available in various grades and sizes, and can be tailored to suit specific requirements, allowing adaptation to diverse applications
  • Environmental friendly: Derived from renewable sources such as wood or coconut shells, it can provide an eco-friendly solution for pollution control and remediation

Whether you’re considering activated carbon to replace existing filtration media or to complement current processes, its selection should be based on a thorough understanding of the specific requirements of the system.

It’s not a one-size-fits-all solution, and that’s where we can help. Our team of experts can offer high-level advice and technical support when it comes to selecting the right activated carbon for your application. Contact us online or call us on +44 (0) 161 938 3000 to discuss your requirements.