Odour control when processing residual household waste
A great deal of household residual waste is produced every day. During the mechanical-biological treatment (MBT) of these fractions, it is of crucial importance to engage in odour control. AIRCON V-XL filters from Desotec have repeatedly proven their added value in France too.
At the end of 2012, there were approximately sixty MBTs in France, which together processed 4.5 million tonnes of residual household waste. MBT (mechanical biological treatment) installations process the household waste that remains after separate collection. The treatment consists of a close sequence of mechanical operations (e.g. sorting) and biological steps (e.g. composting and methanisation). While in the rest of Europe the main focus is on SRF (Solid Recovered Fuel) production or material stabilisation, in France methanisation is generally preferred, with the addition of the composted digestate to the soil or direct compost production.
Such installations inevitably create polluted air flows that have to be cleaned before they are emitted. The amount of air to be treated depends mainly on two factors: the characteristics of the air flows resulting from the process and the dimensioning of the on-site ventilation. Usually, operators of such systems spend about 15 percent of the investment in such an MBT system on odour control. The larger the installation, the more challenging the solution to the odour problem.
Because it is virtually impossible to design biofilters for the treatment of very high air volumes, activated carbon filters are often the ideal solution. They are safer, more compact, require less control and are therefore very efficient. In the case of biogas filters, too, activated carbon filters are emerging as a suitable solution for H2S and VOC capture. This summer, Desotec installed two AIRCON V-XL filters in the Vendée department (France). One has been installed in the acceptance hall, the other in the building where the compost matures. Both process a nominal flow rate of 55,000 m³. A biofilter and an H2SO4 scrubber treat the damp air in the building through a separate circuit, while the activated carbon serves to increase the filtration speed and air quality for personnel.
In the Morbihan department (France), two AIRCON-V filters have ensured an increase in the amount of air that can be purified and improved air quality for the past three years. This installation treats 45,000 tonnes of residual household waste each year. In 2021, a new installation with four AIRCON V-XL filters will be installed to replace and modernise the air filtration system.
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.