Exhaust air purification pharmaceutical industry
In manufacturing pharmaceutical companies, drugs are produced in the form of solutions, gels, granules or even tablets containing the respective active ingredients. These active ingredients, in turn, are predominantly produced in batch process reactors, either in bioreactors or also by extraction.
In the manufacturing process, excipients are added to the respective active ingredients to obtain the desired dosage form of the drug. Among them:
- Solubilizers: ethanol, isopropanol
- Thickening agents: celluloses
- Acidity regulators: citric acid
- Emulsifiers: cetyl stearyl alcohol, gylcerol
- monostearate, lecithin, fatty acid esters,
- polysorbates, polyoxyethylene fatty alcohol ethers
- Sweeteners: sorbitol, saccharin, sugar
- Colorants: yellow orange S
- Preservatives: parabens, sodium benzoate and
- Flavor Corrigents: Vanillin and flavoring agents
The exhaust air problem
Solvents such as ethanol and propanol or long-chain alkanes such as heptane are used as extraction agents. These leave the reactor chamber after completion of the extraction process as so-called VOCs (volatile organic compounds) and can be detected in the exhaust air olfactometrically as odor development or with an FID (flame ionization detector) as total carbon content.
After completion of the respective formulation, further processes follow, such as coating and drying processes. Since some of the auxiliary substances are water-soluble, water-miscible or liquid, these organic compounds enter the production exhaust air as VOCs and can be detected there as odors or total carbon.
In these processes, products of extraction such as tannins, humic acids or oil fractions are present in addition to the alcoholic phases. Exhaust air temperatures of the pharmaceutical industry are in the range of 20 to 40°C. These emissions are evaluated for their VOC content.
Exhaust air purification with UV-C and plasma technology
First, the alcohol is proportionally degraded by radical reactions using plasma technology and converted to acid and formaldehyde. These products can then be converted to carbon dioxide and water with high efficiency via the downstream UV technology.
Products that are difficult to degrade, such as oil components or tanning agents, are also neutralized with this process combination. The basis for the use of these technologies is knowledge of the exhaust air constituents, their concentration in the exhaust air, and knowledge of the relative humidity and exhaust air temperature. With this information, energetically highly efficient exhaust air purification systems can be set up and operated, which are significantly below the limit values of the TA-Luft.
This arrangement is clearly superior to other processes:
- Activated carbon filters have to be replaced at short frequency, while the oxytec system requires hardly any maintenance. The absorption process of the activated carbon filters cannot be monitored and thus represents an uncertainty. In the case of oxytec, the activated carbon filter primarily serves as a catalyst and therefore needs to be changed only very rarely.
- Biofiltration has a much lower efficiency and more space requirements.
- Incinerators cause high investments and high operating costs (gas) Autothermal operation is only possible with recirculation systems (Cges ~4000mg/m³).
Advantages of exhaust air purification via UV-C and plasma
- The limit values of the TA-Luft are fulfilled
- Low investment costs compared to incineration plants
- Low operating costs.
- Low maintenance requirements
- Low space requirement