Scientists in China have built the world’s first integrated reactor capable of converting dissolved CO2 from ocean water into succinic acid, a key precursor for biodegradable polymers like polybutylene succinate (PBS).
The achievement, led by researchers at the Shenzhen Institutes of Advanced Technology and the University of Electronic Science and Technology of China, was demonstrated on the coast of Shenzhen and published this week in Nature Catalysis.
The system represents a new frontier in carbon utilisation: transforming ocean-dissolved CO2, which is present in far greater quantities than atmospheric CO2, into high-value materials for the circular economy.
Electro-Biochemical System Converts Seawater CO2 Into Plastic Precursors
The reactor combines electrochemistry, catalysis, and microbial fermentation in a modular five-chamber system. Incoming seawater first passes through an electrochemical cell where an applied current separates water molecules and acidifies one chamber, releasing CO2 in gaseous form. That CO2 is then directed to a second module, where a bismuth-based catalyst reduces it to formic acid, an energy-rich intermediate.
In the final stage, a genetically optimised marine bacterium—Vibrio natriegens—ferments the formic acid into succinic acid, a widely used building block for bioplastics and other green chemicals.
The team validated the system across 530 continuous hours using real seawater from Shenzhen Bay. The reactor achieved 70% CO2 capture efficiency and an estimated processing cost of around €200 per ton of CO2, placing it among the more competitive carbon-reuse technologies currently in development.
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Importantly, the modular design allows production to be switched to other industrial molecules, including lactic acid, alanine, or 1,4-butanediol, depending on market needs.
Oceans hold 150 times more carbon than the atmosphere, and excess CO2 absorption is accelerating marine acidification. Technologies that extract and repurpose dissolved CO2 could ease pressure on marine ecosystems while supplying low-carbon feedstocks for industry.
Researchers say the reactor could ultimately pair with offshore wind, tidal, or wave energy to form zero-emission marine biofactories that turn ocean CO2 into climate-positive products.
The breakthrough adds momentum to emerging approaches that integrate ocean carbon capture with industrial biomanufacturing, positioning marine systems as strategic assets in the race toward climate neutrality.
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