Page 14 - Case study: Fine dust filtration in Stuttgart, Germany

3. Conclusions

In the city of Stuttgart and elsewhere in Germany, the advocation for effective measures to improve
air quality, including driving bans and other extreme measures, has been greatly discussed by the
civil community. There has been repeated demonstrations from both sides on this issue. The use
of the Filter Cubes could improve air pollution in the short term, contributing to human health
protection, alleviating the social tension created by the debate, and creating a respite while a
longer-term solution is sought.

The critical success factor of the project was the transition from a technical prototype with a limited
range of effect to a large-scale project with an active filtration network of 17 columns along a
250m street in open atmospheric environment. An independent engineering office had previously
simulated the effect of the technology under local conditions such as traffic volume and weather.

The main lesson learned was that proof of concept through large scale installation and
measurements campaigns enables validation of internal development tests and simulations and
provides a basis for further development. In the next step, the extension from particulate matter
filtration to a combined filtration of particulate matter and NO2 requires an increase of filter size
and a 50% increase in air flow.

Scaling up after prototype phase

MANN+HUMMEL is rolling out this technology in various countries around the world. The
technology has already been transferred to a number of countries in Asia such as Japan, China,
Korea and India for market investigation and prototype testing with local partners. The European
market is mostly driven by maintaining legal limits and avoiding regulatory risks, while in Asia and
other emerging markets have a much more intense challenge since these agile markets and their
populations are growing at an astonishing speed. Due to the associated increase in manufacturing
production, traffic, and resource consumption, air pollution and negative effects on human health
are also increasing.

The current state of development of the Filter Cube technology has been made available in
Germany, China, and India for medium scale volume in single batch production until demand
necessitates large scale production. Furthermore, MANN+HUMMEL is extending the product
portfolio for alternative applications by altering the system in shape and size, e.g. transfer to storage
areas and subways.

In the short run, the Neckartor project will evolve over time by analyzing and comparing the
external signals and the archived cleaning efficiency. The target is to optimize power consumption
and filter efficiency together with the maximum usability of the filter, thereby reducing maintenance
costs and downtime. The model needs to balance between optimal filtration efficiency over time
for human protection, and lowest usage of resources in terms of energy, human resources, financial
investment and material costs.

8 Fine dust filtration - Stuttgart, Germany