EPFL researchers have developed a system that generates electricity from osmosis with unparalleled efficiency. Their work, featured in Nature, uses seawater, fresh water, and a new type of membrane just 3 atoms thick
Proponents of clean energy will soon have a new source to add to their existing array of solar, wind, and hydropower: osmotic power. Or more specifically, energy generated by a natural phenomenon occurring when fresh water comes into contact with seawater through a membrane.
Researchers at EPFL’s Laboratory of Nanoscale Biology have developed an osmotic power generation system that delivers never-before-seen yields. Their innovation lies in a three atoms thick membrane used to separate the two fluids. The results of their research have been published in Nature.
The concept is fairly simple. A semipermeable membrane separates two fluids with different salt concentrations. Salt ions travel through the membrane until the salt concentrations in the two fluids reach equilibrium. That phenomenon is precisely osmosis.
If the system is used with seawater and fresh water, salt ions in the seawater pass through the membrane into the fresh water until both fluids have the same salt concentration. And since an ion is simply an atom with an electrical charge, the movement of the salt ions can be harnessed to generate electricity.
A 3 atoms thick, selective membrane that does the job
EPFL’s system consists of two liquid-filled compartments separated by a thin membrane made of molybdenum disulfide. The membrane has a tiny hole, or nanopore, through which seawater ions pass into the fresh water until the two fluids’ salt concentrations are equal. As the ions pass through the nanopore, their electrons are transferred to an electrode – which is what is used to generate an electric current.
Thanks to its properties the membrane allows positively-charged ions to pass through, while pushing away most of the negatively-charged ones. That creates voltage between the two liquids as one builds up a positive charge and the other a negative charge. This voltage is what causes the current generated by the transfer of ions to flow.
“We had to first fabricate and then investigate the optimal size of the nanopore. If it’s too big, negative ions can pass through and the resulting voltage would be too low. If it’s too small, not enough ions can pass through and the current would be too weak,” said Jiandong Feng, lead author of the research.
What sets EPFL’s system apart is its membrane. In these types of systems, the current increases with a thinner membrane. And EPFL’s membrane is just a few atoms thick. The material it is made of – molybdenum disulfide – is ideal for generating an osmotic current. “This is the first time a two-dimensional material has been used for this type of application,” said Aleksandra Radenovic, head of the laboratory of Nanoscale Biology
Powering 50’000 energy-saving light bulbs with 1m2 membrane
The potential of the new system is huge. According to their calculations, a 1m² membrane with 30% of its surface covered by nanopores should be able to produce 1MW of electricity – or enough to power 50,000 standard energy-saving light bulbs. And since molybdenum disulfide (MoS2) is easily found in nature or can be grown by chemical vapor deposition, the system could feasibly be ramped up for large-scale power generation. The major challenge in scaling-up this process is finding out how to make relatively uniform pores.
Until now, researchers have worked on a membrane with a single nanopore, in order to understand precisely what was going on. ” From an engineering perspective, single nanopore system is ideal to further our fundamental understanding of membrane-based processes and provide useful information for industry-level commercialization”, said Jiandong Feng.
The researchers were able to run a nanotransistor from the current generated by a single nanopore and thus demonstrated a self-powered nanosystem. Low-power single-layer MoS2 transistors were fabricated in collaboration with Andreas Kis’ team at at EPFL, while molecular dynamics simulations were performed by collaborators at University of Illinois at Urbana-Champaign
Harnessing the potential of estuaries
EPFL’s research is part of a growing trend. For the past several years, scientists around the world have been developing systems that leverage osmotic power to create electricity. Pilot projects have sprung up in places such as Norway, the Netherlands, Japan, and the United States to generate energy at estuaries, where rivers flow into the sea. For now, the membranes used in most systems are organic and fragile, and deliver low yields. Some systems use the movement of water, rather than ions, to power turbines that in turn produce electricity.
Once the systems become more robust, osmotic power could play a major role in the generation of renewable energy. While solar panels require adequate sunlight and wind turbines adequate wind, osmotic energy can be produced just about any time of day or night – provided there’s an estuary nearby.
The Latest on: Osmotic power generation system
via Google News
The Latest on: Osmotic power generation system
- Getting to Know Your Life Support Systems and Why Recording Coliform Counts Matterson October 7, 2020 at 5:38 pm
Life support systems (LSS) maintain quality water for marine mammals ... Efficiency is based on the time ozone is in contact with the water and the power of the ozone generator. Water in direct ...
- Texas Tesla Tower Titillateson October 5, 2020 at 5:00 pm
But the Van de Graf generator guess might not have been far ... it is hard to tell serious science from chicanery. Wireless power transmission is pretty squarely in that camp.
- Water Purification Uses Home-built Electrolysis Rigon October 3, 2020 at 5:00 pm
If you plan ahead a little bit you could have your own system of water purification to ... the sodium from the chlorine. A twelve volt power source is necessary for this to work.
- Sea the green poweron September 30, 2020 at 5:00 pm
The rotor blades are driven by water currents and coupled to an electric generator through a step ... such as ocean energy including marine current power, osmotic power (from salinity gradients ...
- Probing single-cell metabolism reveals prognostic value of highly metabolically active circulating stromal cells in prostate canceron September 30, 2020 at 11:17 am
A sample processing was started no longer than 30 min after a blood draw. RBCs were lysed by osmotic shock using BD Pharm Lyse Lysing Buffer (BD Biosciences, USA) following the manufacturer’s protocol ...
- Global Central Nervous System Diseases Drug Delivery Technologies, Markets & Companies Research Report 2020 - ResearchAndMarkets.comon September 18, 2020 at 2:26 am
The "Drug Delivery in Central Nervous System Diseases - Technologies ... blood-brain barrier for drug delivery to the brain include osmotic and chemical opening of the blood-brain barrier as ...
- Dictionary of Water Termson August 15, 2020 at 3:42 pm
The proliferation of cotton, pecans and green chile as major agricultural staples owe their progress to the acequia system. acre-foot ... hydroelectric power water use--the use of water in the ...
- Immune-Mediated Haemolytic Anaemiaon August 13, 2020 at 7:56 pm
The immunological destruction of RBCs occurs by extravascular phagocytosis in the spleen or liver, or by intravascular osmotic lysis following the generation of terminal membrane attack complexes of ...
- safety precautions for nuclear power plantson August 18, 2019 at 11:14 am
The country is also ... build a somewhat controversial floating nuclear power station that will employ the ... The groundbreaking plant produces about enough power to make a pot of delicious ...
- Reverse Osmosis Elements and Systems Informationon February 11, 2018 at 5:57 pm
Reverse osmosis elements and systems remove contaminants such as salts, pyrogens, and microorganisms from water to produce clean water as an output. Applications for reverse osmosis elements and ...
via Bing News