This seawater plant will capture 10 tons of CO2 and make 300kg of H2 per day

The UCLA team teamed up with Singapore's water agency and others to build the world's largest ocean-based carbon dioxide removal plant after successful pilot programs. In addition to removing 3,650 metric tons (8,046,873 lb) of greenhouse gases a year, it produces 105 metric tons (231,000 lb) of carbon-negative hydrogen.

Global carbon dioxide (CO2) emissions in 2020 were 4.3 metric tons (9,500 lb) per capita, according to the World Bank. With this figure in mind, researchers from the UCLA Samueli School of Engineering have been working to trap atmospheric CO2 from the oceans in an effort to reduce it.

“This technology can electrochemically enhance and restore the oceans’ capacity for carbon dioxide removal from the atmosphere at a globally relevant scale, thereby mitigating ongoing and accelerating climate change,” said Gaurav Sant, director of UCLA’s Institute for Carbon Management.

After launching seawater-based CO2 removal pilots in Los Angeles and Singapore in 2023, UCLA and its start-up company Equatic are eyeing a US$20-million full-scale demonstration plant called Equatic-1. They're backed by Singapore's national water agency, Public Utilities Board (PUB), Singapore's National Research Foundation (NRF), and UCLA's Institute for Carbon Management (ICM).

“Scaling carbon removal solutions requires technology, bold partners, and a focus on measurable success,” says Gaurav Sant, professor of sustainability at UCLA Samueli. “We have been very fortunate to create this shared vision with our partners in Singapore to scale Equatic’s solutions to the commercial scale and around the world.”

Equatic uses electrolysis to purify seawater from nearby desalination plants. The process breaks down water into hydrogen and oxygen, while storing dissolved and atmospheric CO2 for at least 10,000 years as calcium and magnesium-based materials. Removing dissolved CO2 while enabling the ocean to absorb more of the greenhouse gas activates and expands the ocean's natural CO2-storing ability.

A team of researchers and tech-scaling experts from ICM and Equatic will head out to PUB’s research and development facility in Tuas, western Singapore, to begin building the world’s largest ocean-based CO2 removal plant over the next 18 months.

Equatic-1 will be built in two phases. Beginning in March, the first phase is designed to remove one metric ton (approximately 2,205 lb) of CO2 per day by late 2024. In early 2025, installing nine additional modules will complete phase two. With 10 modules in operation, it’s expected that Equatic-1 will be able to remove 10 metric tons of CO2 per day from seawater and the atmosphere. The Singapore pilot plant was deemed successful after removing 0.1 metric ton (220 lb) of CO2 per day; Equatic-1 could remove 100 times more. The technology could also simultaneously produce nearly 300 kg (660 lb) of carbon-negative hydrogen daily.

“The pilot system commissioned in 2023 provided critical performance data to substantiate our carbon dioxide-removal efficiencies, hydrogen-production rates and energy requirements for the process,” said Equatic co-founder and ICM’s associate director, Dante Simonetti. “The findings helped define the pathway for the design and engineering of Equatic-1 based on scaling performance confirmed by the pilot system.”

PUB has set a target of achieving net-zero emissions by 2045 by adopting a three-pronged approach: replacing fossil fuels with renewable solar energy, investing in research and development to reduce the energy required in water-treatment processes, and capturing and removing carbon released into the atmosphere.

“We are pleased to further our collaboration with UCLA and Equatic to develop a solution that has potential synergies with PUB’s desalination plant,” said PUB chief engineering and technology officer Chee Meng Pang. “At PUB, we firmly believe that technological advancements, delivered in partnership with academia and the private sector, hold the key to addressing the complex challenges posed by climate change.”

Equatic-1’s modular design reduces the risks usually associated with scaling technological innovation. The system will also use selective anodes, newly developed with the support of the US Department of Energy’s Advanced Research Projects Agency-Energy (ARPA-E), to produce oxygen while eliminating the unwanted chlorine byproduct created during seawater electrolysis. This opens a new pathway to carbon dioxide removal at the gigaton scale with the co-production of hydrogen – a clean fuel vital to decarbonizing transportation and industrial applications.