Featured Research

from universities, journals, and other organizations

Renewable energy: Nanotubes to channel osmotic power

Date:
February 28, 2013
Source:
Centre national de la recherche scientifique (CNRS)
Summary:
The salinity difference between fresh water and salt water could be a source of renewable energy. However, power yields from existing techniques are not high enough to make them viable. A solution to this problem may now have been found. Researchers have discovered a new means of harnessing this energy: osmotic flow through boron nitride nanotubes generates huge electric currents, with 1,000 times the efficiency of any previous system.

Diagram of the experimental principle: the osmotic transport of water through a transmembrane boron nitride nanotube.
Credit: © Laurent Joly (ILM)

The salinity difference between fresh water and salt water could be a source of renewable energy. However, power yields from existing techniques are not high enough to make them viable. A solution to this problem may now have been found. A team led by physicists at the Institut Lumière Matière in Lyon (CNRS / Université Claude Bernard Lyon 1), in collaboration with the Institut Néel (CNRS), has discovered a new means of harnessing this energy: osmotic flow through boron nitride nanotubes generates huge electric currents, with 1,000 times the efficiency of any previous system. To achieve this result, the researchers developed a highly novel experimental device that enabled them, for the first time, to study osmotic fluid transport through a single nanotube. Their findings are published in the 28 February issue of Nature.

When a reservoir of salt water is brought into contact with a reservoir of fresh water through a special kind of semipermeable membrane, the resulting osmotic phenomena make it possible to produce electricity from the salinity gradients. This can be done in two different ways: either the osmotic pressure differential between the two reservoirs can drive a turbine, or a membrane that only passes ions can be used to produce an electric current.

Concentrated at the mouths of rivers, Earth's osmotic energy potential has a theoretical capacity of at least 1 terawatt -- the equivalent of 1,000 nuclear reactors. However, the technologies available for harnessing this energy are relatively inefficient, producing only about 3 watts per square meter of membrane. Today, a team of physicists at the Institut Lumière Matière in Lyon (CNRS / Université Claude Bernard Lyon 1), in collaboration with the Institut Néel (CNRS), may have found a solution to overcome this obstacle.

Their primary goal was to study the dynamics of fluids confined in nanometric spaces, such as nanotubes. Drawing inspiration from biology and cell channel research, they achieved a world first in measuring the osmotic flow through a single nanotube. Their experimental device consisted of an impermeable and electrically insulating membrane pierced by a single hole through which the researchers, using the tip of a scanning tunneling microscope, inserted a boron nitride nanotube with an external diameter of a few dozen nanometers. Two electrodes immersed in the fluid on either side of the nanotube enabled them to measure the electric current passing through the membrane..

Using this membrane to separate a salt water reservoir and a fresh water reservoir, the team was able to generate a massive electric current through the nanotube, induced by the strong negative surface charge characteristic of boron nitride nanotubes, which attracts the cations contained in the salt water. The intensity of the current passing through the nanotube was on the order of the nanoampere, more than 1,000 times the yield of the other known techniques for retrieving osmotic energy.

Boron nitride nanotubes thus provide an extremely efficient solution for converting the energy of salinity gradients into immediately usable electrical power. Extrapolating these results to a larger scale, a 1-m2 boron nitride nanotube membrane should have a capacity of about 4 kW and be capable of generating up to 30 megawatt-hours (1) per year. This performance is three orders of magnitude greater than that of the prototype osmotic power plants currently in operation. The next step for the researchers in the project will be to study the production of membranes made of boron nitride nanotubes and test the performances of nanotubes made from other materials.

This project was made possible largely through the support of the ERC and ANR.

Note:

(1) One watt-hour corresponds to the energy consumed or delivered by a system with a power of 1 watt for one hour.


Story Source:

The above story is based on materials provided by Centre national de la recherche scientifique (CNRS). Note: Materials may be edited for content and length.


Journal Reference:

  1. Alessandro Siria, Philippe Poncharal, Anne-Laure Biance, Rémy Fulcrand, Xavier Blase, Stephen T. Purcell, Lydéric Bocquet. Giant osmotic energy conversion measured in a single transmembrane boron nitride nanotube. Nature, 2013; 494 (7438): 455 DOI: 10.1038/nature11876

Cite This Page:

Centre national de la recherche scientifique (CNRS). "Renewable energy: Nanotubes to channel osmotic power." ScienceDaily. ScienceDaily, 28 February 2013. <www.sciencedaily.com/releases/2013/02/130228093509.htm>.
Centre national de la recherche scientifique (CNRS). (2013, February 28). Renewable energy: Nanotubes to channel osmotic power. ScienceDaily. Retrieved July 22, 2014 from www.sciencedaily.com/releases/2013/02/130228093509.htm
Centre national de la recherche scientifique (CNRS). "Renewable energy: Nanotubes to channel osmotic power." ScienceDaily. www.sciencedaily.com/releases/2013/02/130228093509.htm (accessed July 22, 2014).

Share This




More Matter & Energy News

Tuesday, July 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Government Approves East Coast Oil Exploration

Government Approves East Coast Oil Exploration

AP (July 18, 2014) — The Obama administration approved the use of sonic cannons to discover deposits under the ocean floor by shooting sound waves 100 times louder than a jet engine through waters shared by endangered whales and turtles. (July 18) Video provided by AP
Powered by NewsLook.com
Sunken German U-Boat Clearly Visible For First Time

Sunken German U-Boat Clearly Visible For First Time

Newsy (July 18, 2014) — The wreckage of the German submarine U-166 has become clearly visible for the first time since it was discovered in 2001. Video provided by Newsy
Powered by NewsLook.com
Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Obama: U.S. Must Have "smartest Airports, Best Power Grid"

Reuters - US Online Video (July 17, 2014) — President Barak Obama stopped by at a lunch counter in Delaware before making remarks about boosting the nation's infrastructure. Mana Rabiee reports. Video provided by Reuters
Powered by NewsLook.com
Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

Crude Oil Prices Bounce Back After Falling Below $100 a Barrel

TheStreet (July 16, 2014) — Oil Futures are bouncing back after tumbling below $100 a barrel for the first time since May yesterday. Jeff Grossman is the president of BRG Brokerage and trades at the NYMEX. Grossman tells TheStreet the Middle East is always a concern for oil traders. Oil prices were pushed down in recent weeks on Libya increasing its production. Supply disruptions in Iraq fading also contributed to prices falling. News from China's economic front showing a growth for the second quarter also calmed fears on its slowdown. Jeff Grossman talks to TheStreet's Susannah Lee on this and more on the Energy Department's Energy Information Administration (EIA) report. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins