Electricity from the sea

Researchers at the Technion have developed a new method for producing electricity from algae in an efficient and environmentally friendly process. The idea, which was born in the mind of doctoral student Yaniv Schlossberg while swimming in the sea, was developed into a prototype by researchers from three faculties at the Technion with a researcher in "Exploring Seas and Lakes for Israel"

The researchers present in the journal Biosensors and Bioelectronics a new method for producing electricity directly from seaweed. The method was developed in collaboration between the Energy Program and the faculties of Chemistry, Biology and Biotechnology and Food Engineering at the Technion and the Israel Seas and Lakes Research Company (Khiel). The traditional use of fossil fuels involves a lot of environmental pollution and contributes to unusual climatic phenomena that we are witnessing and which worry the whole world. Moreover - also a process their production of these fuels is harmful to the environment. This is the background for the development of new technologies for the production of renewable and environmentally friendly energy.

One of the promising approaches, which has been used by many research groups for decades, is the use ofMicrobial fuel cells. These cells are based on the ability of certain bacteria to emit electrons; Placing such bacterial colonies near an electrode in the cell allows electricity to be generated. This method has two notable disadvantages: the economic cost and the health hazard involving the growth of large amounts of bacteria inside the electrochemical cells.

As a result, another technology was born: Biophotoelectrochemical cells. Here too, similar to the microbial fuel cells, the source of generating electricity in this method is bacteria, but this time it is cyanobacteria (also known as blue-green algae): bacteria capable of carrying out photosynthesis like plants. However, cyanobacteria have their own limitations: first, unlike microbial cells, cyanobacteria do not produce electrons in the dark, since the process of photosynthesis occurs only in the presence of light. Second, to produce a significant amount of electricity, which competes with technologies such as solar cells or hydrogen-based fuel cells, a huge amount of cyanobacteria is required, meaning large and expensive areas.

In the current study, a group of researchers from three faculties at the Technion and the Israel Defense Forces present the production of electricity from another marine source: seaweeds. The research was led Prof. Noam Adir וDoctoral student Yaniv Schlossberg from the Shulich Faculty of Chemistry and the Grand Energy Program at the Technion, in collaboration with their colleagues Dr. Tunde Tot from the Faculty of Chemistry; Prof. Gadi Shuster, Dr. David Meiri, Nimrod Krupnik and Benjamin Eichenbaum from the Faculty of Biology; Dr. Omer Yehezkali and Matan Meirovich from the Faculty of Biotechnology and Food Engineering; and Dr. Alvaro Israel from Hial In Haifa.

The initial development of the method produced an electric current A thousand times bigger and more from that produced from mesiobacteria - a level approaching the currents produced in solar cells. According to Prof. Adir, the high efficiency is due to two main factors: the rapid photosynthesis rate of the seaweed, primarily the green Mediterranean algae called Ulva, and the high salinity of the seawater, which functions effectively as an electrolyte - the conductive liquid in the electrochemical cell. Besides that, unlike electrochemical cells based on cyanobacteria, seaweeds are able to generate electricity day and night; During the hours of light, the energy is obtained mainly from the process of photosynthesis, while during the hours of darkness it comes from molecules that the snail secretes that originate from the respiration process. These molecules, called "electron mediators", deliver electrons to the electrode of the bio-electrochemical cell to generate electricity.

לUsing seaweed to produce electricity has many advantages. They grow quickly and can be grown in the sea or in facilities on land, almost without the need for fresh water and agricultural land.  Energy production methods are divided into two general categories: the most polluting are Carbon positive technologies, which involve combustion and carbon emission processes, damage the atmosphere and contribute to global warming; and Carbon neutral technologies, for example solar cells, whose activity does not involve carbon emissions (although their production and transportation do pollute). The new method presented by the Technion researchers Actually founds a new category: Carbon negative. Not only does it not involve carbon emissions; In the process of photosynthesis, carbon is absorbed and oxygen is released - a process that contributes to the atmosphere. Apart from that, the use of algae to produce electricity in this way does not harm the growth rate of algae and therefore allows its parallel use for other needs in the food, medicine and cosmetics industries.

"It's fascinating to discover how a scientific idea emerged," says doctoral student Yaniv Schlossberg, who came up with the original concept. "The famous philosopher Archimedes came up with what is now called 'Archimedes' Law' in the bathhouse, and it happened to me when I was swimming in the sea, at a time when I was researching the possibility of generating electricity using cyanobacteria. On one of the rocks I suddenly saw a seaweed that reminded me of an electric wire, so I said to myself - seaweed also performs photosynthesis, maybe we can generate electricity from it. The development born from that idea, in the joint work of researchers from different groups at the Technion and the Israel Defense Forces, has now led to a scientific article and I believe it is expected to bring about a significant technological revolution in the energy market."

The Technion researchers built an initial prototype of an electrochemical cell that displays the aforementioned technology. According to Prof. Adir, "using the prototype we demonstrated the production of significant amounts of electricity directly from seaweed. We believe that additional inclusions of the method will further increase the production of electric current and for the first time pave the way for the development of future solutions for the production of green energy in bio-electrochemical cells."

for the article in the journal  Biosensors and Bioelectronics   לcross here