Adsorbents: How molecular filtration is transforming the air we breathe

At a time when air quality is an ever more prominent concern, adsorbents are playing a pivotal role in modern air purification. These remarkable materials underpin effective molecular filtration. By adsorbing and removing hazardous airborne pollutants and gases such as volatile organic compounds (VOCs) and ozone, they make a significant contribution to environmental improvement. But what does adsorption mean, what are adsorbents, how do they work, and where are they used? This article provides answers to these and many other questions.

The demand for advanced air purification systems is steadily rising, fuelled by several factors: 

By definition, adsorbents are highly porous materials that bind pollutants and unwanted molecules from the air to their surface – in other words, they adsorb them. The process by which this binding occurs is called adsorption. In contrast to absorption, where substances penetrate into the interior of a material, adsorption takes place exclusively on the surface. 

Adsorption is based on the principle of intermolecular forces between the adsorbent (the material performing the adsorption) and the adsorbate (the substance being adsorbed). These forces may be physical in nature (such as van der Waals forces) or chemical (such as covalent bonds). The exceptional efficiency of adsorbents is due to their enormous surface area, which is achieved through a microporous structure. 

Various types of adsorbents are used, each suited to specific applications. Some of the most well-known ​ ​examples include:

The possible uses for adsorbents in air purification are extensive and span various sectors. 

Industrial applications

Whether in chromatographic processes in the chemical industry, for safeguarding in pharmaceuticals and medicine, or in the heavy metal industry, adsorbents play a critical role in controlling emissions and managing hazardous gases. Their applications include:

• Removing solvent vapours in chemical plants
• Purifying process air in production facilities
• Supporting clean air in laboratories for sensitive experiments

Use in living spaces and public buildings

In residential areas and public facilities, adsorbents contribte to air quality by:

• Removing odours and VOCs from indoor air
• Filtering allergens and air pollutants in HVAC systems
• Controlling humidity through the use of silica gel in dehumidifiers

As a global leader in filtration technology, MANN+HUMMEL has developed a wide range of products that use adsorbents for molecular air filtration. These innovations are used in various fields, from HVAC systems in buildings to specialised industrial applications. Our product range of molecular filters includes:

• Compact filters (V-cells)
• Honeycomb filters
• Bag filters
• Panel filters
• Cartridge filters
• Drum filters
• Filter modules
• Filter media

Here is an overview of our product highlights:

Research in the field of adsorbents is progressing continuously, with a strong focus on efficiency and sustainability:

New materials

Scientists are developing adsorbents with even higher adsorption capacity and selectivity. The following new materials are particularly promising:

• Metal-organic frameworks (MOFs): Highly porous materials characterised by extremely large surface areas, which can be tailored for specific pollutants. 
• Bioadsorbents: Natural, environmentally friendly adsorbents (such as modified biomass) that are increasingly important for sustainable filtration solutions. 
• Nano-adsorbents: Nanotechnology is opening up new possibilities for highly efficient adsorption materials with unique properties.  

Adsorbents: Focus on regeneration and sustainability

A key trend is the development of regenerable adsorbents. Once saturated, they can be cleaned and reused, and where possible, produced from renewable raw materials – reducing resource consumption and increasing sustainability. Examples of sustainable adsorbents include activated carbon from renewable materials, polymeric adsorbents, biological adsorbents made from modified biomass, and honeycomb filters that can be regenerated. 

MANN+HUMMEL is also a driving force for innovation in the field of sustainable adsorption. We offer solutions that effectively adsorb harmful substances, while remaining both economical and sustainable.  

The importance of adsorbents in molecular air filtration will continue to grow. For facility managers, HVAC engineers, and environmental consultants, this technology offers tremendous opportunities to impact air quality in both indoor and industrial environments. 

The ongoing development of adsorption materials and techniques promises even more efficient and sustainable solutions for air purification. From enhancing established adsorbents such as activated carbon and zeolites to the creation of entirely new materials like MOFs and nano-adsorbents – the future of air filtration is promising.

We are at the forefront of this progress, driving innovations that not only facilitates air quality but also focuses on global environmental challenges. With continued research and innovation, adsorbents will play an even greater role in creating more sustainable future. 

For professionals in facility management, climate control, and environmental consulting, it is essential to keep pace with these developments. By integrating advanced adsorption technologies and keeping up with the latest innovations, professionals will ensure optimal solutions for cleaner air in the years to come.