Equatic's Ocean-Based Carbon Capture Is A Game Changer
Equatic's Ocean-Based Carbon Capture Is A Game Changer
More efficient and cheaper carbon capture is here.
Carbon capture and storage (CCS) should be a generation-defining technology. The ability to literally reverse decades’ worth of climate crimes with little to no side effects seems like something from science fiction. Sadly, at the moment, genuinely impactful CCS is just that: fictional. The technology remains far too energy-intensive and expensive, while also being hard to scale and incredibly difficult to verify. But that might be about to change. Equatic, a carbon removal company born out of UCLA, has announced it will build the world’s largest ocean-based carbon capture and storage facility in Singapore, dubbed Equatic-1, that promises to overcome these challenges. So, has Equatic unlocked this utopian technology? Possibly.
Let’s start with the basics. How does Equatic-1 work?
Most CCS technologies pull carbon dioxide directly out of the atmosphere, which is inefficient and arduous. Instead, Equatic pulls dissolved carbon dioxide out of the ocean. You see, around 30% of our emissions are absorbed by the ocean, and the ocean contains 60 times more carbon than the atmosphere. When dissolved, carbon dioxide turns into carbonic acid, hence why our emissions create ocean acidification. But, this carbonic acid is far easier to isolate and remove than atmospheric carbon dioxide. What’s more, the less carbonic acid in the ocean, the faster it absorbs carbon dioxide, so decarbonising the ocean can dramatically decarbonise the atmosphere.
The idea of using the ocean for CCS is not new. However, Equatic-1 uses a unique electrolytic process developed by UCLA’s Institute for Carbon Management that is not only incredibly efficient, but also produces carbon-negative hydrogen fuel and calcium carbonate as by-products. Let me explain.
The plan is for Equatic-1 to be fed desalinated seawater from Singapore’s national water agency. This water then undergoes electrolysis using Equatic’s oxygen-selective anodes. This splits some of the water into oxygen and hydrogen; the oxygen is released, and the hydrogen is collected and stored. But, during this process, the dissolved carbon dioxide and a little atmospheric carbon dioxide react with dissolved calcium and magnesium in the seawater to form solid carbonate minerals, which are strained out. These minerals are stable for millennia, so they safely lock the carbon away from the atmosphere. What’s more, these minerals are only produced in the water through converting carbon dioxide (and carbonic acid); this means we can easily and accurately verify how much carbon dioxide Equatic-1 has captured by weighing the carbonate minerals it produces. These minerals are also incredibly useful in the construction industry as aggregate, so they can be sold on. But, before the remaining seawater is pumped back into the ocean, where it can absorb more carbon dioxide, its alkalinity must be restored by dissolving alkaline rocks into it.
Using this process, the $20 million Equatic-1 plant promises to capture 3,650 metric tonnes of carbon dioxide each year, making it the second-largest CCS facility in the world and the largest ocean-based CCS facility ever. But it will also produce 105 tonnes of carbon-negative hydrogen and 803 tonnes of solid calcium carbonate minerals each year too.
Okay, so why is this better? Well, it’s more efficient and has far better economics.
The most significant cost of running CCS facilities is energy. Climework’s Direct Air Capture (DAC) technology, which is considered one of the most efficient out there, uses 2.5 MWh of energy per tonne of carbon dioxide removed. But, because removing carbon from seawater is much easier than air, Equatic-1 only uses 2.0 MWh per tonne of carbon dioxide removed, making it 20% more efficient. That might not sound it, but that is a giant leap forward.
But something genuinely astonishing happens when you combine this efficiency with Equatic-1’s brilliant economies. Let me explain using some back-of-the-envelope maths.
Climework’s Orca Plant is the closest in scale to Equatic-1, costing $15 million to build and capturing 4,000 tonnes of carbon dioxide each year at $600 per tonne, making it one of the cheapest CCS facilities in the world. Equatic-1 is 20% more efficient, meaning its cost per tonne should be roughly 20% less at $480. However, don’t forget that Equatic-1 also produces 105 tonnes of hydrogen fuel and 803 tonnes of calcium carbonate yearly, which can be sold for around $5.50 per kg and $1000 per tonne, respectively. These revenue streams can offset the cost of carbon capture and bring the price per tonne down to only $101.78! Many consider $200 per tonne to be the tipping point for CCS. At this price, it becomes commercially viable for industries that can’t decarbonise to pay for CCS to offset their emissions. As such, reaching this point will create a CCS boom that could slash our global emissions. So, the fact that Equatic could, in theory, significantly surpass this figure is astonishing.
Now, these are just rough figures, and I have not considered many potential costs, so Equatic-1 most likely won’t capture carbon so cheaply. However, this shows how Equatic’s approach could dramatically cut the price of CCS in the future. This is great, as they plan to expand past Equatic-1 and build plants capable of removing nearly 110,000 metric tonnes of carbon dioxide per year. In other words, Equatic is on course to be cheap enough and at a large enough scale to have a meaningful positive impact on the climate and the carbon market. Currently, Equatic might be our best shot at unlocking this utopian technology and enabling us to repair the climate damage we have done.
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Sources: Equatic, Equatic, UCLA, Eco-Business, Climeworks, The Guardian, Carbon Brief, Hydrogen Insight, CSIRO, Intratec, CRU