A source of green hydrogen

A few years ago, in the middle of the pandemic, Prof Mingxin Huang It made headlines thanks to an invention that at the time seemed as wonderful as it was promising: A “Anti-Covid-19” stainless steel.. Together with his team, Huang, from University of Hong KongThe perfect alloy has been created to keep door handles, handrails or buttons disinfected, among a long list of surfaces we touch on a daily basis. Experts confirmed that it takes up to six hours of contact with its metal 99.99% of SARS-CoV-2 viruses become inactive.

Huang followsMaking headlines Thanks to its progress in steel, though, its focus is now on another front, one unrelated to the pandemic, though no less important: green hydrogen production.

This is HSS-H2. His name may not be very catchy, however HSS-H2 It could be the key to boosting green hydrogen production. The reason: This is the name of the new stainless steel developed by Huang’s team, a metal that, due to its properties, could make the electrolysis through which hydrogen is obtained cheaper. This is thanks to two of its distinctive properties. The first is its resistance to corrosion. The second: its cost.

Its main strength is resistance. If the Hong Kong team confirms that the new steel is ideal for producing green hydrogen, it is primarily because of its resistance. Its creators present it as stainless steel with a “High corrosion resistance”This allows it to be used in devices designed to work with salt water. This is precisely the great advantage it can offer to facilities responsible for generating clean hydrogen. Its endurance paves the way for the use of seawater, with all the possibilities this opens up.

The goal: to make things easier. Green hydrogen is obtained through… electrolysisa Chemical process Which basically consists of using an electric current to separate the hydrogen from the oxygen in the water. For the resulting fuel to be considered “green,” it must meet a key condition: the energy used during its production must come from renewable sources, such as wind and solar, and be free of carbon dioxide.

For a long time There are scientists Which not only uses renewable energy and without carbon dioxide emissions. Its goal is for the process to be carried out with seawater, not just fresh or salt water, which would expand production possibilities and potentially reduce its cost. For example, Yao Cheng, from the University of Adelaide, worked along these lines, He explainsIf we can use seawater for electrolysis we will save on pre-treatments such as desalination by reverse osmosis. also RMIT Universitywhich developed a method based on catalysts designed to work at sea.

HSS-H2, new ally. In this endeavour, HKU steel can be a valuable ally. “Its performance in saltwater electrolysers is comparable to current industrial practices that use titanium as structural parts to produce hydrogen from desalinated or acidic seawater, while the cost of new steel is cheaper.” pointing to University of Hong Kong. Their conclusions have been published in detail in Materials today The authors have already applied for patents in several countries.

Pay attention to expenses. The new steel offers advantages not only on a technical level. From an economic point of view, it can also be a valuable help, as emphasized by the Chinese organization, which states that electrolyzers used today with desalinated seawater or acidic solutions usually include titanium components coated with gold or platinum, which Determines its price.

“For example, the total cost of a 10MW PEM electrolysis system at its current stage is about HK$17.8 million. [unos 2,1 millones de euros] Structural components represent up to 53% of total expenditures.” Researchers estimate Chinese. According to his calculations, the new steel will reduce the cost of structural materials by about “40 times.”

“At first we didn’t believe it”. This statement comes from Dr. Kaping Yu, one of the scientists involved in the tests, who explains that during the development of the new material they dealt with “non-intuitive” concepts. “In addition to the surprise, we are keen to exploit this mechanism,” he says.

The key to his process is “sequential double passivation,” which allowed him to develop a metal with great corrosion resistance. His new innovation joins other previous innovations, such as “anti-Covid-19” steel or ““super steel”. However, their introduction of the SS-H2 does not mean that they have no work left.

Towards the ultimate goal. “From experimental materials to real products, such as meshes and foams, there are still challenging tasks for water electrolysers –Huang comments.—. We have taken a big step towards industrialization. Tons of SS-H2 based wires were produced in cooperation with a factory in mainland China. “We are developing the most economical SS-H2 application for hydrogen production from renewable sources.”

the pictures: University of Hong Kong

In Chataka: Green hydrogen already has its price index. Its reading is clear: it multiplies the natural gas reading by eight