Energy conservation and carbon reduction can be said to be the current world trend. Many scientists are committed to researching and developing sustainable biofuels to combat climate change. Among them, hydrogen molecules are considered as the most promising energy carriers due to zero emissions and high storage capacity. University of Turku, Finland (University of Turku) converts solar energy into biohydrogen through photosynthesis of green algae.
When green algae are used in photosynthesis, they use solar energy to decompose water and release oxygen to make biomass. Chlorella is also an efficient biocatalyst that converts solar energy and carbon dioxide into vitamins, antioxidants, polymers and carbohydrates.
Yagut Allahverdiyeva-Rinne, assistant professor of molecular plant biomass, says that in previous studies, microalgae cells were incubated in a dark, deoxygenated environment, and then the cells were placed in sunlight to produce hydrogen. However, efficient hydrogen production only lasted for a few seconds.
In the past decade or so, scientists believed that oxygen-induced hydrogenases are the major obstacles to the long-term hydrogen production of Chlorella. Senior researcher Sergey Kosourov pointed out that algae release oxygen continuously during photosynthesis. At the same time, hydrogen is produced, so it is difficult to cultivate and maintain anoxic conditions under sunlight.
Therefore, Turku University researchers based on the basic knowledge of algae photosynthesis to create a new method of hydrogen production. This method does not need to put the green algae in a lack of nutrient environment, so it does not need to exert any pressure on the cells. The researchers pointed out that as long as the oxygen through The exposure of microalgae to strong and short light pulses can significantly prolong the hydrogen production time.
Kosourov said that exposure to pulses of algae does not accumulate oxygen in the medium. Algae also direct electrons produced by water decomposition to hydrogen production rather than biomass accumulation. This effect lasts for several days. Hydrogen production can be maintained for 8 hours.
Studies have shown that the barrier to efficient hydrogen production is not oxygen, but that the two metabolic pathways in the cell are competing. They are the bio-accumulation caused by carbon dioxide fixation and hydrogenation catalyzed by hydrogen.
Allahverdiyeva-Rinne pointed out that this research opens up new possibilities for the creation of highly efficient cell factories that can use sunlight, carbon dioxide and water to make biofuels and different chemicals. The study also provides "a waste" of solar energy to avoid biomass. The method, as well as how to use these energy directly for the manufacture of bio-products, is very helpful for basic research on algae photosynthesis and mass production of biomass fuel.
