In a world grappling with escalating water demand and climate-induced droughts, the race to secure water resources has intensified. Countries like the United States, Israel, and Australia are turning to massive desalination plants to meet their water needs, but these endeavors are not without controversy. Enter Capture6, a groundbreaking startup claiming to have found a solution to desalination’s environmental challenges by leveraging another contentious technology: carbon capture.

A Triple Benefit Approach

Capture6 has recently unveiled plans for Project Octopus, a revolutionary venture in South Korea that integrates a carbon-capture facility with a nearby desalination plant. The objective is ambitious to extract carbon dioxide from the atmosphere and store it in desalination brine, simultaneously producing additional fresh water. If successful, Project Octopus could yield a triple benefit: reducing greenhouse gas concentrations, creating a new freshwater source, and mitigating the environmental impact of desalination.

 Direct-Air Capture and Brine Utilization

The heart of Capture6’s innovation lies in the marriage of direct-air capture technology with brine from desalination plants. Direct-air capture facilities employ a chemical reaction to pull carbon dioxide from the air, storing it in solid compounds or chemical solutions. Capture6 takes this a step further by sourcing brine from wastewater treatment and desalination plants, addressing the challenge of brine disposal that often leads to environmental concerns.

Project Octopus in Action

Situated at the Daesan Industrial Complex in a region plagued by water shortages, Project Octopus tackles water scarcity by using the brine from K-water’s desalination plant. This brine not only serves as a carbon capture medium but is also utilized to extract additional freshwater. The innovative approach doesn’t stop there – Capture6 plans to use the solvent from its direct-air capture operations for additional carbon capture at nearby oil and gas plants.

Challenges and Ambitions

Capture6 acknowledges the challenges ahead, with skeptics questioning whether the facility will have a net negative impact on emissions, given the energy-intensive nature of desalination and direct-air capture. The initial pilot in Korea aims to capture 1,000 tons of carbon per year and produce around 14 million gallons of fresh water. However, the company’s growth goal is to capture almost 500,000 tons of carbon dioxide annually by 2026, accompanied by a significant increase in freshwater production.

The innovative approach of pairing direct-air capture with brine from desalination plants raises eyebrows in the scientific community. 

Daniel Pike, the head of the carbon capture team at the Rocky Mountain Institute, a nonpartisan climate think tank, commends the concept but points out the immense energy needs associated with both processes. “Even assuming you have the solvent, you have an intense energy need just to power a direct-air capture process, and a big challenge we have in direct-air capture is how to improve energy efficiency,” he said. “Then, what they’re doing is they’re also running a very energy-intensive process for deriving the solvent, moving a lot of water around. It’s a lot of energy, a lot of water. That big picture is the challenge here.”

Energy Consumption and Environmental Impact

One of the critical questions surrounding Capture6’s business model is the energy required to reclaim additional water. Ekta Patel, a researcher at Duke University, raises concerns about the environmental implications of increased energy usage. As the company’s main revenue source remains water, the feasibility of its ventures depends on finding an energy-efficient balance in water reclamation.

The company, which has received early funding from several venture capital funds as well as the states of California and New York, announced its first facility last year in Southern California. That facility, known as Project Monarch, will store carbon dioxide in wastewater from a water treatment plant in the city of Palmdale, then sell fresh water back to the city’s water system.

Leo Park, the vice president for strategic development at Capture6, sheds light on the company’s overarching goal, stating, “What we are trying to do is really to decarbonize the water sector. So we’re trying to integrate our facilities into the easiest thing, which is wastewater and desalination plants.”

The Environmental and Economic Impact

The newly announced venture in South Korea, known as Project Octopus, takes the process one step further. The facility will be located at the Daesan Industrial Complex, an oil and gas industrial park in a region of the country that has suffered from water shortages due to an ongoing drought. The Korean state water utility, K-water, is building a seawater desalination plant at the industrial park to provide water to the oil and gas plants, which use thousands of gallons of water to cool down their machinery as it operates.

The Capture6 facility will use the brine created by K-water’s desalination plant to capture carbon dioxide, and it will also use the modified brine to extract even more fresh water that the oil and gas plants can then use in lieu of pumping from less sustainable sources. 

Capture6 also says that the solvent produced by its direct-air capture operations can then be used for additional point-source carbon capture at the nearby oil and gas plants, providing a double emissions benefit before the company buries all the carbon deep underwater. In other words, Capture6 will use the byproduct of water production to create even more water, and it will use the byproduct of capturing carbon to capture more carbon.

Scaling Up for a Sustainable Future

Pike says that the company’s growth goal is extremely ambitious, and it’s unclear whether the facility will have a net negative impact on emissions, given that desalination and direct air capture both require a lot of energy. In the case of Project Octopus, that energy will initially come from Korea’s power grid, which relies heavily on fossil fuels.

“Even assuming you have the solvent, you have an intense energy need just to power a direct-air capture process, and a big challenge we have in direct-air capture is how to improve energy efficiency,” he said. “Then, what they’re doing is they’re also running a very energy-intensive process for deriving the solvent, moving a lot of water around. It’s a lot of energy, a lot of water. That big picture is the challenge here.”

If Capture6 can prove that its facilities store more carbon than they emit, the company won’t have any trouble monetizing its technology. The oil and gas companies in Daesan will buy its produced water for their cooling needs, and K-water will rely on the company to minimize the environmental harms of desalination, which generated backlash when the plant was first announced.

“There were a lot of local concerns about brine discharge because [locals] were worried that it was going to impact the marine ecosystem and fishing activities,” said Park. “Our solution can help minimize brine discharge, so there’s an additional environmental benefit we can generate. This is one of the reasons K-water wanted to work with us.”

Future Prospects and Concerns

Even so, the full-size Capture6 facility will only absorb around half of the brine that the K-water desalination plant produces, meaning the utility will still have to release a lot of toxic liquid into the ocean. Park says he hopes the company can eventually scale up far enough to absorb all the plant’s brine, but they’re not there yet.

Unlike many other direct-air capture companies, Capture6 doesn’t need to sell carbon credits to make money. Park hopes to someday sell credits to private companies seeking to offset their emissions, but for the moment Capture6’s main revenue source is the same as any ordinary desalination plant: water. Park says the company could build future facilities at lithium mines, which also produce brine and need water to operate.

Ekta Patel, a researcher and doctoral student at Duke University who studies the politics of desalination, said the big question about this business model was how much energy it takes for Capture6 to make the new water.

“My mind jumps immediately to the issue of energy,” she said. “How much more energy does reclaiming the additional water take, is it from renewable or nonrenewable sources, and what does that do to the cost of the water?” She added that if “addressing challenges related to carbon emissions and water” required a jump in energy usage, the solution was just “shifting around resource problems.”

A Bold Step Towards Sustainability

Capture6’s Project Octopus represents a bold step towards addressing the challenges posed by desalination, climate change, and carbon emissions. As the world watches this innovative venture unfold, the hope is that it will not only provide a solution to water scarcity but also set a precedent for sustainable practices in the intersection of technology, environment, and industry. Only time will tell if Capture6 can truly revolutionize water sustainability and pave the way for a greener future.