UvA chemists outline methods for hydrogen storage
Hydrogen is an excellent way to transport energy, but what is the best way to store the gas? A national consortium that includes UvA chemist Chris Slootweg received €18 million from the National Growth Fund to answer that question.
The Dutch government is investing heavily in hydrogen technology. Last October, the National Growth Fund provided €18 million to conduct research into hydrogen storage and transport through the temporary organization GroenvermogenNL. UvA chemist Chris Slootweg leads a subgroup of that project with a subsidy of €5.4 million on specifically the large-scale storage of hydrogen. Five doctoral students and one postdoc are being appointed for that purpose, one of whom will work at the UvA.
“One of the challenges of hydrogen storage is that hydrogen is a gas with a very low density,” says Chris Slootweg of the Van ’t Hoff Institute of Molecular Science (HIMS), leader of the research project program on the large-scale storage of hydrogen together with the research organization TNO. For that reason, it is attractive to store hydrogen underground, for example, in old cavities created for salt extraction. Four PhD students in Wageningen, Utrecht, Delft, and Twente will conduct research into this, including how such storage affects the purity of hydrogen.
Hydrogen carriers
The UvA is one of the few universities in the Netherlands with expertise in storing hydrogen above ground. To avoid needing gigantic rooms, the gas must be compressed. Slootweg explains: “That can be done by liquefying it either at high pressure or at extremely low temperatures, but that requires a lot of energy.” That is why the UvA is working on methods to chemically bond hydrogen to another substance—a so-called hydrogen carrier—to transport hydrogen at room temperature.
Hydrogen can play an important role in making our energy systems more sustainable, but sustainably produced hydrogen is still scarce and not suitable for all applications. That is why the Natuur & Milieu Foundation has created a hydrogen scale. It shows that hydrogen should be used primarily for processes that require a lot of energy and where a battery is no longer efficient, such as electric airplanes and container ships where battery packs would simply be too heavy. Electric cars, on the other hand, are almost three times more efficient than hydrogen cars.
A frequently mentioned example is the transport of hydrogen in the form of ammonia. Slootweg says: “This is because ammonia is already produced on a large scale in industry for use in fertilizer. But ammonia is toxic. Plus, to release hydrogen from ammonia you need temperatures above 400 degrees Celsius. We are researching new methods.”
Chemists at HIMS have been researching new liquid and solid hydrogen carriers for years, but comprehensive work is still lacking. A UvA PhD student will work on that in the next few years. Slootweg says: “A PhD student will systematically determine the properties of about 10 potential hydrogen carriers, how much hydrogen they absorb, their storage and release temperatures, their toxicity, and whether the infrastructure is feasible with the aim of selecting promising carriers for large-scale applications.”
Shell
Shell and Gasunie are also partners in the GroenvermogenNL research consortium. The Committee for Cooperation with Third Parties has yet to review the project, although Slootweg does not foresee any problems. “The UvA decided that cooperation is allowed, provided it is sustainable, and this research program fulfills that requirement 100 percent. Besides, we are not working directly with Shell on this project.”
