Researchers have succeeded in producing "green" hydrogen with high efficiency and low costs
Initial hope for mass production of green hydrogen, which will dramatically reduce humanity's CO2 emissions: researchers from Tel Aviv University have developed a new method for producing "green" hydrogen, that is, hydrogen produced without air pollution, with high efficiency using a biological catalyst. Hydrogen is a necessary raw material in both agriculture and industry, but 95% of the hydrogen produced in the world today is "black" or "gray" hydrogen that is produced from coal or natural gas and emits 9-12 tons of carbon dioxide for every ton of hydrogen. According to the researchers, currently the production of 'green' hydrogen is done mainly through a process that requires the use of precious and rare metals and the distillation of water, which makes the 'green' hydrogen up to 15 times more expensive than the polluting 'gray'. The researchers express hope that in the future it will be possible to take advantage of the new method they developed commercially, to lower the costs and switch to using 'green' hydrogen both in industry, in agriculture and as a clean energy source.
The new method was developed by doctoral student Yitzhak Greenberg and Dr. Oren Ben-Zvi, under the guidance of Prof. Yiftah Yacovi from the School of Plant Sciences and Food Security in the George S. Wise Faculty of Life Sciences, and Prof. Lehi Adler-Abramovich from the School of Dentistry at the Sackler Faculty of Medicine, and the center for nanoscience and nanotechnology. The results of the promising study were published in the important journal Carbon Energy.
90% more efficient production process
"Hydrogen is very rare in the atmosphere," explains Yitzhak Greenberg, "and it is produced by enzymes that exist in microscopic organisms, which receive the energy for it from photosynthesis processes. In the laboratory, we actually electrify those enzymes, that is, an electrode replaces the sun and provides the energy. The result is an efficient process, No requirement for extreme conditions, however, the enzyme 'escapes' from the electrical charge and needs to be held in place by chemical treatment An easy and efficient way to attach the enzyme to the electrode and utilize it."
In their new study, the researchers used a hydrogel (a water-based gel) to connect the electrode to the enzyme, and thus were able to produce green hydrogen using a biological catalyst, and with an efficiency of over 90%, meaning that over 90% of the electrons introduced into the system remained in the hydrogen without secondary processes .
"The material of the gel itself is known, but its use to produce hydrogen is our innovation," explains Prof. Yiftach Yacovi. "We soaked the electrode in this gel, which contained an enzyme for producing hydrogen called hydrogenase. The gel keeps the enzyme for a long time even under the electric voltage and makes it possible to produce hydrogen with high efficiency and in environmental conditions favorable to the enzyme, that is, also in salt water, in contrast to electrolysis which requires distilled water. Prof Lehi Adler-Abramovich adds: "Another advantage is that the gel assembles itself: you put the The material enters water and it undergoes self-assembly, that is, it arranges itself into nanometric fibers that form the gel. We showed that these fibers are able to stick the enzyme to the electrode. We tested the gel on two other enzymes, besides hydrogenase, and proved that it is capable of sticking different enzymes to the electrode."
"Today, the production of 'green' hydrogen is done mainly through electrolysis, which requires precious and rare metals such as platinum in addition to the distillation of the water, which makes the 'green' hydrogen up to 15 times more expensive than the polluting 'gray'. We hope that in the future it will be possible to take advantage of our method Commercially, to lower the costs and switch to using 'green' hydrogen - both in industry, in agriculture and as a clean energy source, concludes Dr. Oren Ben-Zvi.
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