Our oceans are among the stronger allies against climate change: absorb huge quantities of carbon dioxide, well 140 times more than that present in the air. But by dint of storing it, the waters are acidifying, damaging fish, corals and whole ecosystems.
Thus, a group of researchers in China has decided to try a recover some of that CO₂. Not only to reduce acidification, but also for reuse it in a useful way: transforming it into biodegradable plastic.
And no, it’s not science fiction. Have already built a working devicetested at sea, which could open to a new way of producing materials starting directly … from salted water.
A system that captures co₂ from the sea
The first problem was technical: How to bring out the CO₂ from the seawithout the system stopping after a few minutes. The previous versions of this technology lasted very little. The reason? THE salts dissolved in marine water (type calcium and magnesium) create incrustations, such as limestone in the kettle at home. And they clog everything.
The new prototype, on the other hand, solved the problem with a solid state electrolyser: a closed system, which uses a membrane to pass only the right molecules, preventing the salts from ruining the mechanism. In practice, the device acidifies water, free carbon dioxide in the form of gas, and collects it.
The test went great: the car worked uninterruptedly for over 22 daysprocessing 177 liters of marine water and recovering 6.5 liters of pure co₂. And it consumed very little energy: only 3 kWh for each kilo of extract.
“Trained” bacteria transform the CO₂ into succinic acid
Keep the carbon, however, was not enough. The researchers also wanted do something useful with that CO₂. Thus, they transformed it into succinal acida substance used for biodegradable plastics, drugs and industrial chemicals.
To do this, they took three steps:
- They converted the CO₂ in Modic acida simple but precious molecule, which Many microorganisms use as a source of energy.
- To do this, they used a new catalystcapable of working at high speed and with an efficiency of the 90%.
- Finally, they genetically changed a marine bacterium, the Vibrio Natriegensvery fast in growth, for Feel only with formic acid and convert it into juicy acid.
And it worked. Bacteria have done their work, transforming Co₂ Marina into a bioplasty ingredient. All without producing waste or additional emissions.
Is it really sustainable?
The system is negative carbon balance: Removes Co₂ from the ocean and allows it to absorb another. Is a closed cyclepotentially replicable along all the coasts of the world. Certain, transform the prototype into industrial technology will take time. But the first tests on a larger scale (from laboratory bottles to 5 -liter bioreattors) have been promising. And each part of the system showed Excellent scalability.
Even the costs are not prohibitive: apreliminary economic analysis speaks of 230 dollars for tonne of caught caughta figure in line with other similar technologies. And here, moreover, there is the value of the product obtainedwhich can be sold. In short, it is not a miraculous solution. But it is a concrete step towards a new way of doing industry, starting from what pollutes.
