Results flow into numerous follow-up projects

It is considered the basis for the climate-friendly energy supply of the future: green hydrogen. That is why politicians want to see an accelerated development of the hydrogen economy. But what is the potential and what are the limits of using this new technology in industry? Researchers at Bremerhaven University of Applied Sciences and the Bremerhaven Technology Transfer Centre (ttz) have been investigating this for two years in the ERDF-funded project "Hydrogen - Green Gas for Bremerhaven". Their results not only provide the basis for numerous follow-up projects, but also concrete recommendations for companies.

Research was conducted into the use of hydrogen technologies in energy supply, as an alternative drive in mobility and logistics, e.g. for forklift trucks, and in the field of e-fuels. In addition, a hydrogen baking oven was developed and put into operation. Despite pandemic-related supply bottlenecks, the researchers are satisfied with the course of the project and their results. "The main goal was to develop hydrogen technology in production, storage and application to the point of market introduction and economic viability, in order to advance the energy transition," says overall project leader Prof. Dr. Carsten Fichter from Bremerhaven University of Applied Sciences. The aim was to show companies that hydrogen technologies can be operated in a fail-safe manner and can represent an alternative to conventional technology. This was the case in all sub-studies. Nevertheless, it became apparent during the course of the project that further developments are needed and that the infrastructure would have to be expanded in order to be able to switch completely to this form of energy supply.

Industry has long recognised that CO2 emissions must be reduced in order to achieve climate protection goals.However, for companies to make greater use of hydrogen systems in the future, they must not only be technically mature, but also economically viable."Companies are generally open to and interested in the use and application of hydrogen as an energy carrier, but at the same time they are still hesitant when it comes to investments in this area," Prof. Fichter knows.As the research results show, the new technology is currently much more expensive."To make hydrogen technology also financially interesting, new technological developments should be adopted in small steps and in ongoing processes."

In the sub-study "Microgrids - self-sufficient units", Bremerhaven University of Applied Sciences investigated whether an entire industrial area can be operated exclusively with renewable energies in the future.For this purpose, the researchers converted a container into a test facility and produced green hydrogen in it with the help of solar and wind energy.This was used as a storage medium to compensate for fluctuating power feeds.In addition, a battery storage system was installed to compare the two systems."Ecologically, the hydrogen system is more advantageous over the entire life cycle compared to the battery storage system. It is also easier to expand the storage capacity of hydrogen systems. However, battery systems are much more mature and, in the case of smaller storage units, more cost-effective than the hydrogen system," says Prof. Fichter. Whether a conversion to hydrogen is financially worthwhile for large industrial companies and quarters is currently being investigated in the "IWAS - Lune Delta" project.

Another important aspect on the way to a climate-friendly economy is transport. The sub-study "Hydrogen in Logistics and Mobility" researched the state of the technology in the mobility sector and finally looked at the conversion of forklift trucks.Although these often have battery storage, the performance decreases as the state of charge decreases.The charging times are also often very long.Here, hydrogen has the advantage that it can be refuelled in gaseous form in a short time.The use of green hydrogen also avoids CO2 emissions. "Although the CO2 emissions of the individual vehicles are not high, in total they are still noticeable", says Prof. Fichter. In the practical test, the forklifts with fuel cell technology were basically convincing. "Acceptance is important for use in the companies. The feedback from the employees was very positive. The hydrogen forklift was able to demonstrate the desired work performance and was on a par with the battery-powered forklifts used. The possible operating time was also sufficient for the daily working hours of the drivers," says Prof. Fichter. Only refuelling with a mobile system was a challenge. "A solution for continuous use would have to be found here, which would have to be individually adapted to the respective operation.

In addition to fuel cell technology, e-fuels are another option for powering vehicles in a climate-friendly way. These green energy sources, produced with the help of electricity, can be used in combustion engines, for example. In a special process called methanisation, synthetic natural gas (SNG) is produced from hydrogen and carbon dioxide.A test facility has been developed and set up in Bremerhaven for this purpose.The SNG can be mixed directly into the gas grid, for example, or used in vehicles, as described above.In the project, the focus was, among other things, on the construction of a smaller test plant, the selection of a suitable catalyst system for methanation and the variation of the composition of the source gases hydrogen and carbon dioxide, for example, in order to realise the highest possible yields."The plant was successfully built and the tests successfully carried out. These serve as the basis for quite a bit of research work that is being built up and is already underway," says Prof. Fichter.

In order to investigate whether hydrogen can also be used in food production as an alternative to conventional energy sources, a hydrogen oven was developed and tested in another sub-study using the baked goods industry as an example. The main task was to develop a combustion chamber and an air conduction system that optimally transfer the relevant temperature and humidity profiles for the production of baked goods. In addition, a comprehensive safety concept was created and approved by a certified body. "The results show that baked goods can be produced with consistent product quality.Hydrogen can therefore basically be used as an energy carrier for industrial baking ovens.However, there is still a need for optimisation in terms of heat losses.This is the basis for further projects," says Prof. Fichter.

In order to get citizens in particular more involved in the process of developing and understanding how to implement the new technology, the "Hydrogen Green Gas for Bremerhaven" project presented itself as part of the annual "Hydrogen Week North" organised by Bremerhavener Gesellschaft für Investitionsförderung und Stadtentwicklung mbH (BIS). "A transformation of the energy system cannot succeed without the accompanying social transformation. The support of the population is an indispensable prerequisite for this," says Prof. Fichter.

The two-year project "Hydrogen - Green Gas for Bremerhaven" was funded by the State of Bremen and the European Regional Development Fund (ERDF) with around 20 million euros.

The complete final report can be found at https://www.hs-bremerhaven.de/de/forschung/projekte/gruenes-gas-fuer-bremerhaven.