Removing contaminants in the chemical industry

Europe’s chemical production industry is a major pillar of its economy and society, employing 1,2 million people directly and supplying essential products to many other sectors.

From our experience in this industry, we have found that air purification and waste water treatment are common challenges in different stages of the production processes. Activated carbon can be a very effective solution in various stages at all these stages and in variety of chemical companies.

In this article we discuss these common problems and their possible solutions.

The market: Chemical production and sales in the EU

With an annual turnover of € 570 million, the EU’s chemical producing industry is the second largest in terms of sales in the world, after China.

Base or commodity chemicals account for 60% of EU chemical sales, excluding pharmaceuticals. These include petrochemicals; polymers, plastics and resins; and basic inorganics such as sulphuric acid and fertilisers.

Specialty chemicals, such as paints and crop protection, account for another 27%. Along with pharmaceuticals, this sector is growing.

Jeroen Callewaert, DESOTEC Chief Commercial Officer, says: “The beauty of the chemical industry in Europe is that it is wide-ranging and of essential importance on a global level, both for research and development and for manufacturing.”

“At DESOTEC, we are happy to be able to support all these diverse types of activities with our purification solutions, from solving environmental challenges to adding value in the production chain.”

Aims and applications 

There are several reasons why it may be necessary for chemical companies to treat emissions:

  • Complying with environmental legislation related to emissions to air, water or soil
  • Improving hygiene conditions for employees and those living near the factory
  • Removing impurities to add value to a product e.g. via decolourisation

Treatment of air emissions

Many chemical plants across Europe are seeking solutions for contaminated air emissions.

The venting of storage tanks and reactors is one area of concern, including during cleaning or maintenance processes. 

Working spaces, while only lightly polluted, may also require ventilation and treatment to improve working conditions and reduce odour nuisance in the neighbourhood.

Contaminants found in air emissions include aromatic hydrocarbons, such as benzene and toluene; polyaromatic hydrocarbons (PAH), such as naphthalene; chlorinated molecules, like monochlorobenzene (MCB); and brominated molecules.

Emissions from burning processes and flue gases can include dioxines and hydrochloric acid.

Wastewater treatment

Wastewater resulting from the production process often requires purification before it can be safely discharged into watercourses. Production waters include those from extraction processes or from precipitation reactions.

Cleaning and maintenance processes may result in wastewater that contains residues from the original chemicals or their reactions, plus the solvents used in the cleaning process.

Treatment is necessary to reduce chemical oxygen demand (COD) levels, adsorbable organically bound halogens (AOX).

Persistent organic pollutants (POPs) are often found in wastewaters resulting from the production of herbicides, fungicides and pesticides. They do not biodegrade, and thus require treatment before discharge. Other well-known POPs are PFAS molecules such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) which can be present in fire extinguishing water

Purification of chemical streams

Frequently, manufacturers want to improve the quality, and thus the value, of a chemical product itself. This can be a standard step in the production process or can be implemented temporarily for a specific batch.

Decolourisation of products, for example biofuel and the amino acids methionine or lysine, could mean that these products can be sold for a higher price. Odour removal, for example from bio-ethanol, can also add value.

The removal of impurities and micropollutants from certain chemicals, such as hydrochloric acid, amino acids and cyclopentadiene, allows them to be used in a wider variety of applications.

“We work closely with a large chemical company in France,” explains DESOTEC sales manager Eva Verbrugghe. “We purify the amino acid they produce. Activated carbon is used to remove colour and impurities which improves the overall quality of the end-product.”

DESOTEC’s solutions for clients

DESOTEC offers a full-circle service for many sectors of the chemical industry. Our solutions can be permanent or installed on a temporary basis during the maintenance process or as a bridge if something goes wrong with an existing installation.

Let’s take a closer look at why chemical companies make DESOTEC their first port of call.

  • Flexibility

Our filters can be fitted in 30 minutes, making them highly desirable in an industry where even short shutdowns can easily cost €1-2 million. As they are supplied on a rental basis, they do not require financial investment.

“We were contacted by a chemical plant in Germany for a temporary project to treat their VOC emissions,” explains Mario Westerkofort, DESOTEC’s sales manager in Germany.

“On site they have a thermal system that normally purifies this specific gas flow. However, every few years, this system requires maintenance.

“During this down-time a temporary system is essential to ensure continuous production, so we are glad that we could help them out.”

  • Ease of use

DESOTEC filters are ‘plug and play’, making them simple to install and operate.

“Mobile activated carbon solutions are a rather new technique for certain applications,” adds Jeroen Callewaert. “More and more they are being recognised as a very valuable and reliable option.”

  • Modularity

If flow increases or decreases, DESOTEC can add and remove units swiftly and simply, ensuring solutions are continually optimised.

Sometimes filtration is the first stage in the treatment process, removing toxicity from wastewater so that it can be sent for biotreatment before safe discharge into the environment.

“A large chemical manufacturing company reached out to us because their existing water purification system, a physico-chemical treatment step, was insufficient,” says Alexandre Hornero, DESOTEC’s regional business director in Spain. “After treatment, the polyaromatic hydrocarbons (PAH) in their wastewater remained too high to discharge.

“An additional polishing step with activated carbon takes care of this and allows the customer to safely discharge their wastewater.”

  • Environmental soundness

As DESOTEC carbon can be recycled, it is a better use of natural resources. Companies can rely on the fact that we do not just displace contaminants, but destroy them completely in our furnaces.

As Jeroen Callewaert says: “For us, sustainability is not just a fashionable word; it is a concrete reality in our daily professional lives with our customers in the chemical industry. The sustainability of each process in the chemical industry is becoming scrutinised and evaluated. DESOTEC has the answers, and will help to render the chemical industry even more sustainable in the future.”

  • Customer satisfaction

Increasingly, manufacturers are discovering DESOTEC and replacing existing systems with our solutions.

Frédéric Meunier, sales manager for France, says: “A specialist in storing chemical products was searching for a better way to purify the venting gases from their storage tanks. By replacing their scrubber with activated carbon, they do not have to worry about their VOC emissions anymore.”

The chemical industries we supply are generally multinationals with multiple sites around Europe and the world. Once they have tried out our filters on one site, they frequently turn to us for solutions at other locations.

  • Off-site waste removal

DESOTEC solutions mean that companies do not have to deal with waste on site, which is especially necessary in the pharmaceutical industry where high-quality products are essential. Instead, clients are supplied with closed units.

DESOTEC has permits to transport waste from anywhere in Europe for correct recycling in Belgium. We have staff working full-time on waste legislation, whereas our clients may lack the expertise to deal with the relevant authorities. These waste streams of saturated carbon are recycled as much as possible. All molecules that were adsorbed, are completely removed during the reactivation process and fully destroyed in the fluegas treatment, resulting in the emission of only harmless water vapour.

Get in touch

We are happy to discuss our solutions with engineering companies, those responsible for health and safety, plant managers and others involved in the chemical manufacturing industry. Contact us to discuss the solutions that DESOTEC can provide for your sector.


At DESOTEC’s facilities, all used carbon is analysed so the right measures can be taken for handling and removing the saturated carbon out of the mobile filters. All molecules that were adsorbed on the activated carbon at the customers’ site, are desorbed inside DESOTEC’s reactivation furnaces. These contaminants are then fully destroyed, in accordance with National and European legislationby an incineration and neutralisation setup. The entire installation and it's emissions are under continuous on-line monitoring, which guarantees that only harmless water vapour is seen exiting the chimney.