Nav: Home

Chemical hydrogen storage system

March 07, 2019

Hydrogen is a highly attractive, but also highly explosive energy carrier, which requires safe, lightweight and cheap storage as well as transportation systems. Scientists at the Weizmann Institute of Science, Israel, have now developed a chemical storage system based on simple and abundant organic compounds. As reported in the journal Angewandte Chemie, the liquid hydrogen carrier system has a high theoretical capacity and uses the same catalyst for the charging-discharging reaction.

Hydrogen carries a lot of energy, which can be converted into electricity or power, and the only byproduct from combustion is water. However, as hydrogen is a gas, its energy density by volume is low. Therefore, pure hydrogen is handled mostly in its pressurized state or liquid form, but the steel tanks add weight, and its release and usage is hazardous.

Apart from tanks, hydrogen can also be masked and stored in a chemical reaction system. This is in principle the way nature stores and uses hydrogen: In biological cells, finely adjusted chemical compounds bind and release hydrogen to build up the chemical compounds needed by the cells. All these biological processes are catalyzed by enzymes.

Powerful catalysts mediating hydrogen conversion have also been developed in chemical laboratories. One example is the ruthenium pincer catalyst, a soluble complex of ruthenium with an organic ligand, developed by David Milstein and his colleagues. With the help of this catalyst, they explored the ability of a reaction system of simple organic chemicals to store and release hydrogen.

"Finding a suitable hydrogen storage method is an important challenge toward the 'hydrogen economy,'" the authors of the publication explained their motivation. Among the conditions that have to be fulfilled are safe chemicals, easy loading and unloading schemes, and as low a volume as possible.

Such a system, consisting of the chemical compounds ethylenediamine and methanol, was identified by Milstein and his colleagues. When the two molecules react, pure hydrogen is released. The other reaction product is a compound called ethylene urea. The theoretical capacity of this "liquid organic hydrogen carrier system" (LOHC) is 6.52 percent by weight, which is a very high value for a LOHC.

The scientists first set up the hydrogenation reaction. In this reaction, liquid hydrogen carriers ethylenediamine and methanol were formed from ethylene urea and hydrogen gas with hundred percent conversion when the ruthenium pincer catalyst was used.

Then they examined the hydrogen release reaction, which is the reaction of ethylenediamine with methanol. Here, the yield of hydrogen was close to 100 percent, but the reaction seemed to proceed over intermediate stages and ended with an equilibrium of products. Nevertheless, full re-hydrogenation was possible, which led the authors to conclude that they had indeed developed a fully rechargeable system for hydrogen storage. This system was made of liquid organic compounds that are abundant, cheap, easily handled, and not very hazardous.

Its advantage is the simple nature of the compounds and the high theoretical capacity. However, to be more efficient and greener, like setup in nature, reaction times must still be shorter and temperatures lower. For this, even "greener" catalysts should be examined.
-end-
(3442 characters)

About the Author

Dr. David Milstein is the Israel Matz Professor of Organic Chemistry at the Department of Organic Chemistry of the Weizmann Institute of Science, Rehovot, Israel. His research interests focus on the development of fundamental organometallic chemistry and its application to the design and implementation of new sustainable, green, catalytic reactions for synthesis and energy.

http://www.weizmann.ac.il/Organic_Chemistry/milstein/

Wiley

Related Hydrogen Articles:

Superconductivity: It's hydrogen's fault
Last summer, it was discovered that there are promising superconductors in a special class of materials, the so-called nickelates.
Hydrogen energy at the root of life
A team of international researchers in Germany, France and Japan is making progress on answering the question of the origin of life.
Hydrogen alarm for remote hydrogen leak detection
Tomsk Polytechnic University jointly with the University of Chemistry and Technology of Prague proposed new sensors based on widely available optical fiber to ensure accurate detection of hydrogen molecules in the air.
Preparing for the hydrogen economy
In a world first, University of Sydney researchers have found evidence of how hydrogen causes embrittlement of steels.
Hydrogen boride nanosheets: A promising material for hydrogen carrier
Researchers at Tokyo Institute of Technology, University of Tsukuba, and colleagues in Japan report a promising hydrogen carrier in the form of hydrogen boride nanosheets.
World's fastest hydrogen sensor could pave the way for clean hydrogen energy
Hydrogen is a clean and renewable energy carrier that can power vehicles, with water as the only emission.
Chemical hydrogen storage system
Hydrogen is a highly attractive, but also highly explosive energy carrier, which requires safe, lightweight and cheap storage as well as transportation systems.
Observing hydrogen's effects in metal
Microscopy technique could help researchers design safer reactor vessels or hydrogen storage tanks.
The 'Batman' in hydrogen fuel cells
In a study published in Nature on Jan. 31, researchers at the University of Science and Technology of China (USTC) report advances in the development of hydrogen fuel cells that could increase its application in vehicles, especially in extreme temperatures like cold winters.
Paving the way for more efficient hydrogen cars
Hydrogen-powered vehicles emit only water vapor from their tailpipes, offering a cleaner alternative to fossil-fuel-based transportation.
More Hydrogen News and Hydrogen Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.