Chemical companies are subject to stringent standards. A French resins producer for ion exchangers had to comply with strict federal VOC (volatile organic compound) emission limits. These VOCs are released during their drying processes. The new standard specifies that the carbon content may no longer exceed 100 g/h.

To be fully compliant, the company recently called upon Desotec for the treatment of these contaminated air flows. The results of the pilot test proved to be extremely positive, so a full-scale solution is being implemented and will be operational in the course of 2019.

Scrubber

In seeking solutions to achieve the quota, the company first tested a scrubber on one of the flows. This treatment method was not effective enough as only 80 % of the VOCs could be captured. Their consultancy agency then advised them to get in touch with Desotec.

Their first request to Desotec came in March 2018 after which the site was frequently visited to be able to correctly assess the situation and offer a high performing solution. First of all, it had to treat the most challenging emission point (with a flow rate of 1,000 to 2,000 m³/h). Desotec installed an Aircon 2000 skid, a test system with a fan and a chimney. This pilot installation gave us a good idea about the activated carbon consumption and the load. Activated carbon appears to be extremely suitable for dealing with these steep peaks in VOC concentrations resulting from the drying process which takes place in batches. Analyses quickly showed that this system proved to work well and could serve as a basis for the development of the total solution.

Centralised air treatment

Desotec is currently preparing the complete installation of an activated carbon filtration system that will bring the three emission points together and treat them from 2019 onwards. The Aircon V-XL, with a capacity of 11 tons of activated carbon for flow rates up to 55,000 m³/h, will filter the total airflow with a flux of 10,000 to 15.000 m³/h. Results from the pilot installation prove that the VOCs are captured in an efficient way. They also perfectly reflect the adsorption capacity and make it possible to calculate the annual cost price for the final installation in detail, so that the customer can budget this correctly. Our turnkey approach and ‘plug & play’ concept offers added value for the customer. In addition, Desotec can significantly reduce the number of mobile filter replacements due to the large capacity of the Aircon V-XL filter. An additional advantage is that the saturated activated carbon can be reactivated without any problems.

Goodwill

Thanks to this pilot installation, the French customer is assured that the problem is fully under control. As a result, the public authorities gave this company extra time to work out an efficient and accurate total solution.

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.