Benzene is not really a substance that you wish to emit into the environment. The emission of this organic compound is therefore subject to strict regulations everywhere. In order to control benzene emissions, a major Polish chemical company relied on Desotec’s services. The challenge was resolutely tackled by installing an AIRCON 2000 filter.

A Polish chemical giant specialises in the production of chlorobenzene and hydrogen chloride (HCl). Benzene is inevitably released during the production processes. At one of the emission points, the concentration was up to 0.34 kg/h, which is too high according to the new local ecological regulations. The company was faced with the challenge of reducing these emissions by at least half. It had already tried several solutions to significantly reduce emissions, but without success.

The company already knew Desotec as a supplier of solutions for the treatment of organic components in hydrogen chloride and for the removal of free chlorine on the same production lines. It contacted us and asked us to find a suitable treatment for this challenge as well.   As the emission of pollutants is a discontinuous process and it is impossible to calculate the exact total benzene emissions accurately, we agreed to carry out a ‘full scale' pilot test in November last year. As a solution, we proposed activated carbon filtration with an AIRCON 2000 filter.

The results of this test installation were very positive. Calculations learned that the activated carbon filter performed even above expectations. The original concentration of 0.34 kg/h was only 0.0009 kg/h after treatment. That means a 98 % reduction in emissions.

After three months of testing, the customer decided to make permanent use of this mobile activated carbon filter. The results show that the AIRCON 2000 filter is saturated just after three months. It is therefore sufficient to replace the filter four times a year in order to achieve a permanent solution. As it is a rental solution, the company does not need to invest, and it also has a clear overview of the operational costs. With the installation of a second filter, it is possible to reduce the benzene concentration even further, but that is not immediately necessary.

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 legislation, by 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.