Capturing CO2 from seawater and producing hydrogen

Equatic, a spin-off from the University of California, is embarking on a large-scale project to extract carbon dioxide (CO2) from the ocean while simultaneously producing green hydrogen. This innovative approach aims to address climate change by reducing CO2 levels in the ocean, which can help mitigate ocean acidification, and contribute to the generation of green energy.

After successfully completing a pilot project, Equatic is now moving forward with the construction of a demonstration plant in Singapore, with an investment of €18.5 million. This plant will serve as a testing ground to refine their technology and demonstrate its viability on a larger scale. By harnessing ocean water, Equatic’s process not only captures CO2 but also produces green hydrogen—a clean fuel that can be used in various applications, from powering vehicles to generating electricity. This project represents a promising step toward sustainable solutions for both carbon reduction and clean energy production.

The Equatic-1 plant, set to be the largest of its kind, aims to make a significant impact on CO2 removal and green hydrogen production. Once operational, it will have the capacity to extract 3,650 tons of CO2 from the ocean annually while generating 105 tons of hydrogen.

The process used by the plant involves electrolysis, where seawater is electrified in a desalination facility. This process triggers a chemical reaction that separates water into hydrogen and oxygen. Meanwhile, the CO2 captured from the seawater is converted and stored as a solid material, specifically in the form of lime and magnesium.

The oceans, much like forests, play a crucial role in capturing CO2 from the atmosphere. By effectively removing and storing CO2 from seawater, Equatic-1 can help the oceans absorb more CO2 from the air, contributing to efforts to combat climate change. This dual benefit of CO2 removal and hydrogen production positions the Equatic-1 plant as a promising solution for sustainable energy and environmental health.

What Is Carbon Capture?

This technology might be the only thing standing between the world and devastating climate change.

Many long-term climate change plans aim to keep global warming below 2 degrees Celsius, but few suggest that cutting fossil fuel emissions and investing in renewable energy alone will suffice. Instead, most of these plans depend heavily on a strategy called carbon capture and storage (CCS). CCS refers to technologies that capture CO2 emissions and store them in a way that prevents them from contributing to climate change. Theoretically, widespread adoption of CCS could enable a scenario with negative CO2 emissions while still using fossil fuels.

However, CCS technology is still in its infancy, primarily operating in coal plants, where capturing CO2 is somewhat feasible due to the high levels of emissions produced. The WA Parish plant in Texas, for instance, captures around 5,000 tons of CO2 daily, which is about 90% of the CO2 it emits. While this might seem beneficial, the plant still contributes to climate change since it continues to emit CO2. Even if all coal plants implemented CCS, overall climate change would likely worsen rather than improve.

Moreover, captured CO2 is often injected underground to enhance oil recovery, allowing more fossil fuels to be extracted and burned, which adds to emissions elsewhere. This means that, despite some initial successes, CCS is not a viable standalone solution for achieving negative emissions.

Current research indicates that to achieve negative emissions, efforts must shift toward directly removing CO2 from the atmosphere rather than relying solely on CCS from industrial sources. In summary, while CCS could play a role in reducing emissions, it cannot independently secure a sustainable future without addressing the need to pull CO2 from the air.

Out of Thin Air

Efforts to develop technology for capturing CO2 from the atmosphere face significant challenges due to the low concentration of CO2 in the air—up to 300 times lower than in emissions from coal plants. This makes atmospheric carbon capture and storage (CCS) more costly and less effective.

One promising startup, Climeworks, is creating large CO2 collectors capable of capturing up to 50 tons of CO2 per filter annually. They have built two CCS facilities, with the larger one able to remove nearly 1,000 tons of CO2 from the atmosphere each year. Climeworks and similar companies, such as Global Thermostat and Carbon Engineering, use simple chemical compounds, like amines or hydroxides, to capture CO2. These compounds react with CO2 and can be regenerated through heating, allowing for the captured CO2 to be collected for various uses, including underground storage.

However, despite these advancements, the scale of the problem is daunting. For instance, if Climeworks produces 150 collectors annually, it could remove 75,000 tons of CO2 per year in ten years. This figure is negligible compared to the nearly 40 billion tons of CO2 emitted by humans in just one year. Thus, at their current production rate, it would take a billion years to make a significant impact on atmospheric CO2 levels. Climeworks aims to capture 1% of annual global emissions by 2025, a goal considered highly ambitious given the current scale of emissions.

Last Hope?

Skepticism surrounds carbon capture and storage (CCS) technology due to its novelty and current inefficiency in compensating for carbon emissions. With the global carbon budget expected to be exhausted in less than a decade, CCS might be essential to mitigate the worst impacts of climate change, especially since achieving carbon neutrality seems unlikely.

To enable CCS to make a meaningful impact on CO2 levels, it is crucial to increase funding for research and implementation today. Projects like the WA Parrish plant can support CCS development, even if they don’t sequester substantial CO2, as they may lead to discovering more cost-effective methods.

Initiatives such as the Virgin Earth Challenge and the Carbon XPrize are incentivizing private groups to innovate in CCS development through competitions. These efforts encourage entrepreneurs to explore alternative and less expensive CCS methods. Various startups are already investigating unconventional solutions, such as converting CO2 into charcoal or capturing it from biofuel plants.

At XPrize, competitors focus on carbon conversion, transforming CO2 into valuable products like chemicals, fuels, and building materials. While not every solution will succeed, several could evolve into significant industries, making CCS more profitable and effective.

Despite the uncertainty surrounding CCS’s success, it remains a critical component in the fight against climate change. The urgency to develop effective carbon capture technologies is paramount, as failing to do so may result in irreversible environmental damage. Therefore, enhancing support for CCS research and innovation is vital for a sustainable future.

Pilot in Los Angeles

Equatic conducted a pilot project in Los Angeles to test their technology for removing carbon dioxide (CO2) from the ocean. During this pilot, they successfully extracted 100 kilograms of CO2 daily from the seawater, which also resulted in the production of several kilograms of green hydrogen as a byproduct. With the successful completion of this initial phase, Equatic is now ready to scale up their operations and move forward with larger, more extensive projects. This next phase will involve building a demonstration plant designed to significantly increase their capacity for CO2 removal and green hydrogen production.

Scaling Globally

Equatic-1 will be constructed in two phases. The first phase, starting in March, involves building an initial module capable of removing 1 ton of CO2 from the ocean each day, set to be operational in 2024. In 2025, nine additional modules will be added, increasing the total CO2 removal capacity to 10 tons daily, while also producing 300 kilograms of hydrogen each day. After achieving these initial goals, Equatic plans to scale up and commercialize their technology globally, with future facilities aimed at removing up to 110,000 tons of CO2 from the ocean annually.

CO2 compensation

While Equatic-1's CO2 removal capabilities seem significant, they need context. The World Bank reported that the average global CO2 emissions per person in 2020 were 4.3 tonnes, with the Netherlands averaging 7.5 tonnes per capita. By the end of 2025, when Equatic-1 is fully operational, it will remove enough CO2 from the ocean to offset the annual emissions of approximately 487 Dutch individuals. If Equatic expands to a larger facility, it could potentially offset the annual emissions of about 14,666 Dutch people.

Certificates

The Equatic system offers significant benefits due to its modular design, allowing for easy repairs and the ability to scale up in various locations. Boeing has already partnered with Equatic, agreeing to purchase CO2 certificates generated from the carbon capture efforts of the new plant.

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