New filter cubes at the Neckartor in Stuttgart

Tuesday - 23 July 2019

New filter cubes at the Neckartor traffic junction in Stuttgart set to reduce concentration of nitrogen dioxide

Ludwigsburg/Stuttgart, July 23, 2019. Starting today, MANN+HUMMEL, the filtration expert, will replace its 17 Filter Cubes III at the Neckartor traffic junction in Stuttgart by 23 enhanced systems. After positive results regarding the reduction of fine dust pollution, the company had already retrofitted the existing systems in April on a temporary basis with newly developed combifilters. These filters enable the retention of fine dust particles and also nitrogen oxide from the ambient air. The new Filter Cubes III to be installed from today are also equipped with this technology together with an increased filter surface area and high performance blowers. Based on simulations carried out by an external simulation office, MANN+HUMMEL assumes that the use of high performance systems will reduce the concentration of nitrogen dioxide by around 10 to 30 percent.

Filter Cubes III from MANN+HUMMEL have been in operation since December 2018 for the purpose of reducing fine dust pollution at the Neckartor traffic junction in Stuttgart. Analysis undertaken up to now has shown that the filters reduce the local concentration of fine dust pollution by around 10 to 30 percent. In February 2019, MANN+HUMMEL presented a new combifilter medium for the reduction of nitrogen oxide (NO2) at polluted locations at its company headquarters in Ludwigsburg. In order to make a quick contribution towards the reduction of nitrogen dioxide pollution at the Neckartor traffic junction in Stuttgart, the company, in consultation with the Ministry of Transport in the state of Baden-Württemberg and the city of Stuttgart, opted to install the technology of the existing systems on a temporary basis.

The first intermediate results of the interim solution indicate that the desired reduction in nitrogen dioxide will be achieved, and, after the replacement, which starts today, of the existing systems with enhanced systems which have an increased filter surface area and high performance blowers, MANN+HUMMEL expects a high level of efficiency. The local concentration of nitrogen dioxide should be reduced by around 10 to 30 percent. In the past, the limit value for nitrogen dioxide (40 micrograms per cubic meter on average throughout the year) was regularly exceeded at the "Am Neckartor" measuring station.


Less nitrogen dioxide through use of activated carbon

The newly developed combifilter includes a filter layer that retains particles and additional activated carbon layers to adsorb nitrogen dioxide. In this process, highly porous activated carbon media are used, and due to their large surface area, are able to efficiently absorb nitrogen dioxide. The pollutants are retained using a number of different processes, e.g. physical adsorption, chemical binding and catalytic reduction. The technology is characterized by a particularly low drop in pressure. As a result, it is able to efficiently clean the air while using a low amount of energy. The Filter Cubes include combifilters and also fans to draw in the ambient air. The filters are able to bind more than 80% of the nitrogen dioxide and fine dust contained in the ambient air that is drawn in. Control electronics allow the user to adapt the operation of the filters to match operating conditions and therefore react to the current air quality. Sensors record air and weather data which are transferred to a cloud and analyzed.


Further information

The use of filter columns around the world is useful wherever people are particularly exposed to nitrogen dioxide and fine dust pollution. This applies, for example, to roads with high traffic volumes and large road junctions. Further areas of applications could include bus stops or underground railway stations. MANN+HUMMEL is also developing filtration concepts which can be directly integrated in bus stops or installed in the form of advertising or information panels.

Thanks to its decades of experience in filtration and its global production network, MANN+HUMMEL is able to implement the use of filter cubes in further polluted locations in just a few months. By using this technology, municipalities threatened by driving bans have the opportunity to achieve a rapid improvement in air quality. By using several filter cubes, an area-wide effect is achieved on site and comparatively little installation space is required.

Further new developments from MANN+HUMMEL, such as the brake dust particle filter and fine dust particle filter, help to improve the overall emission balance of vehicles. MANN+HUMMEL also offers highly developed combifilters for the interior of vehicles, which protect the vehicle occupants against particles and gases. Now, the company has expanded its expertise in the area of activated carbon to the reduction of nitrogen dioxide in the ambient air.

Contact Person

Laura Montag
Manager Corporate Relations | Spokesperson