Use of activated carbon in accordance with the Technical Instructions on Air Quality Control (TA-Luft)

Essen, 13 June 2024 – Compliance with the Technical Instructions on Air Quality Control (TA-Luft) is of crucial importance for companies that emit air pollutants. Activated carbon is an effective and proven solution for minimising environmental pollution by using it as an adsorbent for pollutants from exhaust air sources. Activated carbon is used in various industries to ensure compliance with the TA-Luft.

These include, among others, the chemical industry, metal processing, energy production, waste management, the food industry and the automotive sector. The limit values according to TA-Luft vary depending on the type of industry and the pollutants emitted. There are limit values for dust, sulfur dioxide, nitrogen oxides, carbon monoxide, volatile organic compounds (VOC), heavy metals, odors and other pollutants. The exact limits are set out in the TA-Luft and depend on various factors such as the type of plant, production capacity and emission source. Activated carbon can be used in a variety of applications for exhaust air purification to remove harmful gases and vapours from the air. Some of the most common processes in which activated carbon is used for exhaust air purification are:

• Adsorption of volatile organic compounds (VOCs):

In the chemical industry, VOCs are often emitted that are harmful to health and pollute the environment. Activated carbon can be used to adsorb these VOCs from the exhaust air.

• Removal of sulfur compounds:

In processes that produce sulfur compounds, such as in the petrochemical industry or in wastewater treatment, activated carbon can be used to remove sulfur compounds such as hydrogen sulfide from exhaust air.

• Odour removal: 

Unpleasant odours can arise in the food industry, waste management and other industries, which can be neutralised by using activated carbon in filter systems.

• Removal of pollutants from flue gases: 

Pollutants such as nitrogen oxides (NOx) and mercury can be present in the flue gases from combustion processes, such as in power plants or waste incinerators. Activated carbon can be used to adsorb these pollutants and reduce emissions.

• Removal of organic vapours:

In the varnishing and printing industry, as well as in pharmaceutical production, organic vapours may be released that can be removed from the exhaust air by using activated carbon.

However, the specific limit values that can be met with activated carbon depend on various process parameters, such as the type and concentration of the pollutants, the volume flow of the emission source, the exhaust air temperature and the operating method of the emitting production plant. Therefore, it is recommended that companies that must comply with the TA-Luft limits seek professional advice to ensure that the activated carbon filters are adequately designed for their specific requirements. By selecting and sizing the filter systems correctly, companies can ensure that the installed air purification system meets the requirements of the TA-Luft.

Use of an activated carbon filter for odour and total carbon removal in a waste storage area in accordance with the TA-Luft guideline

Controlling odours and pollutant emissions in waste storage areas presents operators with significant challenges in reducing environmental pollution and protecting air quality in the surrounding area. This application note describes the use of an activated carbon filter for the removal of odours and total carbon in a waste storage facility in accordance with the TA-Luft guidelines, through the effective adsorption of organic compounds. The activated carbon filter enables reliable compliance with legal requirements and is an economical and environmentally friendly solution compared to exhaust air post-combustion in discontinuous operating processes.
Organic emissions can vary greatly in waste storage areas. The most common organic emissions include:

§  Aldehydes: These organic compounds are formed by the decomposition of organic materials and can cause unpleasant odours.

§ Ketones: Ketones are another group of organic compounds that are produced when waste decomposes and can also contribute to odour nuisance.

§ Aromatic Compounds: Aromatic hydrocarbons such as benzene, toluene and xylenes can be released from various waste materials and are potentially harmful to health.

§ Alkanes and alkenes: These organic compounds may also result from the decomposition process of organic waste and contribute to the total carbon emission.

§ Sulfur Compounds: Sulfur-containing organic compounds such as mercaptans and thiophenes can be released from certain waste materials and lead to unpleasant odours.

The exact composition and concentration of these organic emissions can vary, depending on the type and quantity of the deposited waste, the storage conditions and other influencing factors. The German Technical Instructions on Air Quality Control (TA-Luft) specifies specific limit values for the above-mentioned groups of substances in waste collection centres, with the exact values depending on the type of plant and local conditions. The volume flows to be treated depend on the size of the storage hall and the associated air exchange.

Typically, these are in the range of 10,000 – 80,000 m³/h. Thanks to the modular design of the Plug & Clean adsorber series from CarboTech, we can offer a suitable solution for such an application with our Plug & Clean 40,000. To ensure that the limit values are continuously adhered to, it is recommended that two adsorber systems be installed in series. The first filter acts as an operating filter, while the downstream filter serves as a police filter and ensures that the limit values are adhered to even if the operating filter is saturated. The series connection also allows the filter bed of the operating filter to continue to be used even if the emission values at the outlet of the operating filter exceed the limit values. This helps to optimise operating costs. The measurement of the limit values requires the monitoring of the inlets and outlets of both filters using FID or PID. The monitoring interval (continuous or discontinuous) is determined by official approvals.

As soon as the operating filter is saturated, the filter module is replaced. The police filter takes the place of the operating filter and a new module is installed as a police filter. Thanks to the clever arrangement of the exhaust air ducting systems and the use of the Plug&Clean design, such a change can be made within 1 hour. This avoids a longer operational outage and the operation can continue continuously and smoothly. By reactivating the saturated activated carbon and the possibility of reuse, CarboTech creates a circular and sustainable solution.