Ultimate solution to global warming?

Hydrogen bicycles and cars have been mass-produced for years. In these vehicles, the usual polluting lithium battery has been replaced by a fuel cell that converts hydrogen, a non-polluting fuel, into electricity. However, most of today’s hydrogen is still produced from natural gas in a very polluting process and is therefore called gray hydrogen. Not only is natural gas a non-renewable energy source, but it also creates carbon dioxide when burned, which damages our environment and contributes to global warming.

Enter a new discovery from TAU, which could accelerate the industrial transition from the use of polluting gray hydrogen to environmentally friendly green hydrogen: researchers have identified a mutant of a known strain of microscopic algae that allows , for the first time, the production of green hydrogen via photosynthesis on a scale adapted to industrial requirements. Hydrogen gas can thus be produced solely from renewable energy and in a climate-neutral way, significantly reducing our carbon footprint and greenhouse gas emissions to stabilize global temperatures.

Humanity’s transition to using green hydrogen could be the ultimate solution to the problem of global warming.

microscopic algae

Continuous production achieved

The study was led by PhD student Tamar Elman, under the supervision of Professor Iftach Yacoby of the Renewable Energy Laboratory of The George S. Wise School of Life Sciences at Tel Aviv University. The study was recently published in the prestigious journal Cell Reports Physical Science.

While the production of green hydrogen is possible through solar panels connected to devices that perform the breakdown of water into hydrogen and oxygen (electrolyzers), the researchers explain that it is an expensive process. , requiring precious metals and distilled water. In nature, hydrogen is produced as a byproduct of photosynthesis for periods of minutes by microalgae, single-celled algae found in all water reservoirs and even in soil. However, for this biological process to become a sustainable source of energy, humanity must engineer strains of micro-algae that produce hydrogen for days and weeks.

Professor Yacoby explains that as part of the laboratory tests, the researchers identified a new mutant in the microscopic algae that prevents oxygen from accumulating at any light intensity, and therefore hypothesized that a continuous production of hydrogen could be obtained. Using bioreactor measurements in liter volumes, they were able to prove that hydrogen can be produced continuously for more than 12 days.

According to Professor Yacoby, the new mutant overcomes two major obstacles that have so far hindered the continued production of hydrogen:

  1. Oxygen buildup in the process of photosynthesis – Typically, oxygen poisons the enzyme that produces hydrogen in algae, but when mutating, increased respiration removes oxygen and allows favorable conditions for growth. continuous production of hydrogen.
  1. Loss of energy to competing processes – And that includes fixing carbon dioxide in sugar. This too has been resolved in the mutant and most of the energy is channeled for continued hydrogen production.

To industrialize these results, the research team led by Prof. Yacoby is working on a pilot program for larger volumes and on the development of methods that will make it possible to extend the hydrogen harvesting time, in order to reduce its cost to competitive levels. “The rate of hydrogen production from the new mutant is as high as a tenth of the theoretically possible rate, and with the help of further research it is possible to improve this even further,” Professor Yacoby concludes.

Tamar Elman and Professor Iftach Yacoby in the lab

Teresa H. Sadler