Treating TOC and odours after increasing production

This leading Dutch manufacturer of carpet tiles commissioned a new production unit to enable it to realise its plans to scale up.

Until that point, its TOC emissions had been well within permitted limits, so treatment had not been necessary. However, the increased production capacity would take emissions over the limit.

The company needed to put a treatment solution in place before starting to boost production volumes.

It had previously worked with DESOTEC to purify air emissions at other sites, and been impressed by the efficiency and versatility of activated carbon. It contacted us to arrange an exploratory meeting.

One of the main challenges was that a rapid solution was required. The company planned to raise production levels in 6 months, and wanted technology in place that would be fully operational by then.

After analysing sources, rates and concentrations, we found that emissions would exceed limits at two locations.

At one source, there was a flow rate of 4 000 m³/ h and a TOC concentration of 64 mg/m³. This flow also included styrene emissions from a latex-based bonding agent, which produced low levels of odours.

A second solution was also required for three combined flows of 200 m³/ h each, with a TOC value of 72 mg/ m³.

In both cases, the TOC concentration needed to be reduced to below 20 mg/ m³.

We proposed an Aircon H filter containing 6 500 kg of activated carbon: enough to purify these airflows for a year. Being horizontal, it could easily be installed under a canopy close to the building, as requested by the client.

Another challenge was the temperature of the airflows. These were slightly above 100°C, while the activated carbon filters can handle a maximum temperature of 70°C. We catered for this through carefully designed pipework construction, and by suctioning ambient air to reduce the temperature.

The installation of the pipework and fan is currently underway, while the filter installation is scheduled for a few months’ time. For safety reasons, DESOTEC will also install a carbon monoxide sensor on the exhaust.

An additional benefit is that the filter will also remove the low level of odour pollution, caused by styrene components.

Should production levels change in the future, it will be simple to add, remove or replace filters. This could also be necessary if regulations concerning TOC or odours are tightened, as is increasingly happening across Europe.

As part of our full-service solution, we handle all filtration waste. Saturated carbon is transported in closed filters safely away from customers’ sites, and taken to DESOTEC facilities. All used carbon is analysed so the right measures can be taken for handling it.

All molecules that were adsorbed on the activated carbon at the customers’ sites are completely destroyed in DESOTEC’s furnaces in accordance with national and European legislation. Where possible, the carbon is reactivated, driving down costs and raising sustainability. The furnace and its emissions are under continuous on-line monitoring, which guarantees that only harmless water vapour is seen exiting the chimney.