Treating VOC emissions from coated steel parts

At busy, complex industrial sites, the last thing managers need is another piece of equipment to worry about. When it comes to treating air emissions and wastewater, they want simple solutions that just work. That’s exactly what Desotec’s full-service mobile sustainable filtration solutions provide. This long-running project in the steel industry shows how our plug-and-play activated carbon filters require minimal preparation, monitoring or follow-up, leaving the customer free to focus on its core business.

The problem

A plant in Belgium produces and paints steel sheets.

Air emissions from the paint booths contain high levels of volatile organic compounds (VOCs). On environmental and health grounds, the site must comply with a very low permitted limit of just 50mg/ m³.

Many years ago, the customer contacted Desotec for a solution that is still running today.

The solution

Although the customer had not conducted detailed measurements of flow rates and concentrations before contacting us, we were able to draw on our expertise to propose a solution.

Desotec engineers calculated that a single Aircon V-XL would be capable of handling the air flow and compounds in question. As it’s a large filter, it would last a long time between exchanges, minimising cost and disruption to the customer.

Installing the filter was rapid and easy. All that was required was a concrete slab on which to place it: thanks to its small footprint and plug-and-play system, there was no need for the customer to spend time or money remodelling the site.

As soon as it was installed, the filter began treating VOCs in the air flow. While some alternative treatments require lead-in times, activated carbon is a simple technology that just adsorbs any compounds in air flows that are passed over the filter bed – making it an ideal solution for intermittent flows.

The results

The client has asked an external lab to take regular measurements at the outlet of the filter. These prove that the filter is successfully reducing VOCs to below the permitted level, leading to great customer satisfaction and continued collaboration with Desotec.

When a breakthrough of VOC emissions is detected, the client contacts Desotec for a filter exchange. We bring a new filter, which is swiftly swapped for the old one in a process that requires little to no production downtime.

As part of our full-service solution, we handle all filtration waste, lifting another burden from the customer. We transport the closed filter away from the client’s site and take it to our facilities. We analyse the used carbon so we can determine the correct way to handle it.

The waste carbon is treated in our furnaces, where all VOCs are removed and destroyed. The carbon is then reactivated and recycled, boosting sustainability and driving down costs for the customer.

As filters are supplied on a rental basis, there are no large, up-front costs for the customer. Desotec’s system is modular, so filter units can be added or removed at any time to optimise the process or adapt to changing requirements.

However, when the solution just works, as in this case, clients can forget about the filters! That frees them up to get on with producing the steel sheets that are so essential for industries across Europe.