Treating chlorinated and fluorinated VOCs from cleaning processes in the medical devices sector

1. We deliver solutions rapidly, thanks in part to our network of regional hubs.
2. Despite the adsorption of high levels of fluoride and chloride compounds, the carbon can be reactivated.
3. Our system is modular and flexible, allowing for the later addition or removal of filters if required.

This multinational company manufactures medical devices at its headquarters in northern Italy. Its rigorous cleaning and degreasing processes use solvents such as Vertrel (C5H2F10) and isopropyl alcohol.

The exhaust air contains a high concentration of fluorinated and chlorinated volatile organic compounds (VOCs) including methylene chloride (DCM), plus per- and polyfluoroalkyl substances (PFAS). 

A stricter limit for total organic carbon (TOC) emissions of 50mg/m³ pushed the company to find a new treatment solution to reach compliance before the deadline. 

The business already had fixed activated carbon filters on site for other projects, so knew that this technology worked well. However, for the application in question, very large volumes of activated carbon would be required, making the task of emptying and refilling the filters on site unfeasible. 

An alternative would be a regenerative thermal oxidiser (RTO). However, this would entail huge capex costs as the RTO would need to be made of stainless steel to withstand the corrosive effects of the chlorinated compounds combined with condensation. At that time, in 2021, supply chain issues had sent steel prices sky high, as well as extended the timescale for delivery and installation of RTOs.

The company was in the process of analysing its options when it met DESOTEC at the ECOMONDO trade show in Italy and learned for the first time of the mobile activated carbon filtration concept. 

The fact that mobile filtration is a low investment solution, with the only capex costs being piping, made it a very attractive option for this client. DESOTEC’s full-service model, including filter rental, installation and exchange, as well as carbon waste handling, was also a major advantage.

The set-up has now been in place for over three years and is considered permanent. The client is pleased to have found an effective full-service solution, freeing staff up to focus on their core expertise and business.

Regular outlet checks prove the filters are successfully reducing the VOCs to below the required level, allowing the client to demonstrate compliance to the environmental authorities. 

Filter exchanges take place every six months and are quick and simple, requiring minimal downtime or disruption. 

DESOTEC transports the spent carbon in closed filter units away from the client’s site for treatment. We take it to our facilities, where it is sampled and treated in our furnace, and all adsorbed compounds are desorbed and destroyed. 

Carbon from most applications can be reactivated for reuse, boosting sustainability, driving down costs, and avoiding the price fluctuations of virgin carbon. In cases where reactivation is impossible, we send the spent carbon to a specialist third party for safe disposal. 

With this client, we were initially unsure whether we would be able to reactivate the carbon due to the high concentration of chlorinated and fluorinated compounds, but it has proven to be possible thanks to our state-of-the art facilities. 

The client is now evaluating the possibility of using DESOTEC solutions elsewhere at its site – perhaps to replace other fixed filters, which are due for maintenance. 

The company knows that in case of emergency, DESOTEC can deliver filters fast with no investment costs needed. 

Unlike fixed filters or RTOs, our mobile filters can be placed on a temporary or long-term basis. If, for example, lower emissions limits were imposed, we could expand the set-up by placing further filters in series while the client researched and evaluated the optimal long-term solution.