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Is the age of 'blue energy' using seawater coming?

Developed nano tube with 8000 times more efficiency

The world is now very interested in 'green energy', but 'blue energy' is preparing to take over.

Blue energy is key to getting electricity by using the chemical difference between fresh and brine. Now scientists have succeeded in extracting blue energy using stamp-sized membranes and nanotubes. If this could be greatly expanded at low cost, it would be expected that the river could provide carbon-free power to millions of countries with coasts that meet the ocean.

Science and Popular Mechanics have recently reported that Rutgers University scientists have made breakthroughs in the development of 'blue energy', which takes advantage of the natural interactions that occur in the encounters between rivers and seawater.

The difference in the charge of energy-rich salt generates electricity. This is also why our body's electrical system is activated by salty electrolytes dissolved in water.

In 2013, French scientists made this film. They made a ceramic film out of silicon nitrate. The film was then pierced with 'sodium boron nanotubes' (BNNT). BNNTs, which are used to investigate high-strength synthetic materials, have a high negative charge, which can prevent negatively charged water ions. In fact, when French scientists placed a BNNT-treated membrane between fresh and brine, they discovered that positive ions moved from salt water to fresh water, but most of the negatively charged ions were blocked.

The charge imbalance between the two was so strong that the researchers estimated that a 1 square meter membrane containing millions of pores per square centimeter could generate about 30 megawatts per year. That's enough to power over 400 homes.

However, it has not yet been possible to make stamp-sized films.

The Rutgers team wanted to use the magnetic field to overcome this challenge. The problem is that BNNT is not magnetic. So Cetyndaq used a coating to make the nanotubes magnetic. Finally, the team used plasma beams to etch some of the material on the top and bottom surfaces of the membrane, leaving the tubes open on both sides.

If the efficiency is increased, the capacity of 2000 nuclear power plants can be generated.

When the researchers placed the membranes in a small vessel separating the brine and fresh water, they produced 8000 times more power per area than the previous French team's BNNT experiment. The team expects this performance to be much better in the future.

"We are not yet using all the capabilities of the membrane," says Setindaq. This is because the efficiency of BNNT is now only 2%. If this efficiency is increased, it will be possible to put the blue energy that scientists have long thought of into practical use.

Compared to the first of these possibilities, the Rutgers team has made a lot of progress, but there is still plenty of room for progress.

The potential of blue energy comes from its immense scale. The river flows about 37,000 ㎦ freshwater into the sea every year. This intersection between fresh and salty seawater creates the possibility of generating a lot of electricity.

According to a recent estimate, it is possible to produce 2.6 terawatts of electricity, which can be obtained by operating 2000 nuclear power plants.

Semih Cetindag, a PhD student at Rutgers University, recently announced that he has overcome the challenges of blue energy at the Materials Research Society in Massachusetts.

Electricity is produced by the difference in the charge of fresh and salty water

Estuaries, or deltas, where rivers and oceans meet, have enormous energy potential because of the way freshwater and salty water interact and redistribute each other.

The charge on the water particles works in the same way as the magnetic charge. The same charge repels each other. Putting a strong negatively charged nanotube in the water blocks other negative charges. Arranging the water in this way means creating two separate pools with enormous charge differences between them.