Clean Production for Clean Mobility

When it comes to environmental compatibility, heavy-duty road transport does not have a good reputation. Rightfully so, because until now trucks have been real climate sinners: A fully loaded forty-ton truck consumes around 30 to 40 liters of diesel per 100 kilometers. So far, there are no real alternatives on overland routes, because electrically powered trucks do not achieve the necessary ranges. But a promising technology is already waiting in the wings: hydrogen propulsion.

Using hydrogen to generate energy is not a novel idea. Nevertheless, the general public’s interest in the topic has been limited, with its attention focused on fossil fuels and renewable energies such as solar and wind power. Hydrogen-based fuel cells, on the other hand, have been dismissed. Their production was too costly and, moreover, only possible in small quantities. To counter this objection, the project »H2GO – National Fuel Cell Production Action Plan« was launched. Its goal is to develop and roll out industrial technologies for the economical production of fuel cells. The overall project is being funded by the German Federal Ministry of Digital Affairs and Transport with a sum of around 80 million euros from the Automotive Industry Future Fund. The funding is coordinated by NOW GmbH, and the Project Management Jülich (PtJ) is responsible for implementation. The focus is on the question of the feasibility of mass production for road-based heavy-duty transport.

H2GO combines the expertise of 19 Fraunhofer institutes in five subgroups along the process chain of fuel cell production. Fraunhofer IPK is a member of the subgroup for the development from the half plate to the bipolar plate. The central task of our researchers is to develop a cleaning module for the automated cleaning of bipolar plates.

High-Tech in its Purest Form

The requirements for the automated cleaning of the bipolar plates quickly became clear to the scientists: It had to be climateneutral, precise, dry, and residue-free. With these aspects in mind, the process chosen was the novel high-pressure CO2 blasting.

To apply this technology, Fraunhofer IPK's laboratories are being expanded to include a newly designed CO2 purification cell in which researchers can experiment and develop during and beyond the course of the project. With the help of funding of around 1.5 million euros, the cell will be equipped with state-of-the-art CO2 purification technologies.

In high-pressure CO2 blasting, liquid carbon dioxide is used as the blasting medium at a pressure of up to 4000 bar. The carbon dioxide jet gently cleans surfaces before and after the individual production process steps without damaging existing coatings. Contaminants can be removed precisely thanks to the variably adjustable jet diameter. This process allows the thermal influence on the sensitive bipolar plate to be kept low.

In addition to CO2 high-pressure technology, the cell accommodates the latest snow blasting and dry ice blasting technology. For precise and automated cleaning, the cell is equipped with an industrial robot. In addition, manual guidance of the blasting equipment is possible. A quick-change system allows the robot to switch automatically between the different blasting processes. There is no shortage of potential applications for the new cleaning technology, as Fraunhofer IPK researcher Philipp Burgdorf emphasizes: »In the future, we also want to investigate the processing of composite materials such as carbon fiber-reinforced plastic. For us, this opens up a wide range of topics for further research, for example in the aerospace, automotive and wind energy sectors.« For the time being, however, Burgdorf and his team are devoting themselves to the task at hand within the framework of H2GO: making heavy goods traffic more environmentally compatible.