When hydrogen reacts oxygen in a fuel cell, electricity is generated with only water vapour as emissions.
This electrochemical basis for hydrogen technology is old, but its recent applications are becoming increasingly important in moving away from fossil fuels e.g. in heavy traffic and electricity production.
The core question that has come up is how to produce the hydrogen for fuel cells.
Hydrogen has traditionally been produced from fossil raw materials such as natural gas, but it can also be produced in an electrolyser by breaking down water into hydrogen and oxygen using an electric current. This makes hydrogen an emission-free fuel if the electricity has been produced without emissions.
We developed a fuel cell electrolyser system, i.e. a reversible fuel cell system, that produces hydrogen and, when operated in reverse, electricity. The device can be installed e.g. in connection with a wind farm, making it possible to store environmentally friendly wind power as hydrogen and convert it back into electricity during peaks in consumption. The device fits in a 10ft shipping container and can easily be transported to a vehicle refueling station or connected to a chemical industry process that uses hydrogen as a raw material. The device can be implemented on a usable scale,
...explains Research Scientist Ville Saarinen from VTT’s fuel cell team.
Weak efficiency has hindered the production of emission-free hydrogen and thus also the proliferation of hydrogen technology.
Commercial electrolyser technologies are based either on alkali or PEM (Proton Exchange Membrane) technology, which is also used in fuel cell vehicles, achieving about 60% efficiency, while bi-directional operation is not possible. VTT’s team used solid oxide cell (SOC) technology.
Solid oxide cell technology and its required operating temperature of 700 degrees allow extremely high efficiency in hydrogen production. We can reach 80–90% with it,
Unlike a PEM fuel cell, VTT’s reversible solid oxide cell (rSOC) can also directly utilise other fuels besides hydrogen, including natural gas or biogas, i.e. methane.
Fuel flexibility can prove to be a very important factor in the gradual transition to an emission-free energy system over the next 20 years.
At the moment, the production of hydrogen by solid oxide cell technology is primarily hindered by price. For example, unlike in PEM cells, no expensive platinum catalysts are used in the manufacture of solid oxide cells, but the production of ceramic electrolytes and cells assembled from them is technically demanding.
VTT’s fuel cell team developed the fuel cell electrolyser system as part of the three-year BALANCE-EU project, seeking to identify, quantify and analyse national activities dealing with the diverse aspects of rSOC technology. The project ends in November this year.
Earlier this week, seven major companies of the energy and maritime sector, including Deme, Engie, Exmar, Fluxys, Port of Antwerp, Port of Zeebrugge and WaterstofNet, signed an agreement in order to develop new projects that can offer to the the production, transport and storage of hydrogen. Through the agreement, companies assist in Belgium's climate target to reduce CO2 emissions by 80% until 2050.