Mantel’s molten salt technology could revolutionise industrial carbon capture

Cameron Halliday’s story, going from a dedicated MIT PhD student to heading up Mantel as its CEO, pretty much exemplifies a remarkable leap forward in the quest to curb industrial CO₂ emissions. For a long time, one of the biggest hurdles in carbon capture technology has been finding materials that can reliably soak up CO₂ at the really high temperatures typical of industrial processes, think furnaces, kilns, boilers, you name it. Many materials tend to break down quickly under those conditions, which then impacts both efficiency and business viability. Halliday’s big break came around 2019, when he discovered that certain molten salts, specifically lithium-sodium ortho-borate, could absorb over 95 percent of CO₂ and keep doing so without degrading over thousands of cycles. That was pretty impressive.

This discovery actually originated in Halliday’s early research at MIT, and it relies on the fact that these molten salts behave like liquids at high temperatures. This liquid-like property prevents the fractures or cracking that normally cripple solid sorbents. Basically, the salts react with CO₂ in a reversible way, so you can trap the gas, then release it by turning up the heat further. The result? The CO₂ comes out in a pretty pure form, which makes transportation easy and opens up possibilities for reuse, so, rather than being a waste, CO₂ can become a resource.

Now, traditional carbon capture methods often rely heavily on burning lots of energy, mainly steam, to strip the CO₂ away. Mantel’s system, though, actually captures and reuses heat, by integrating water to produce high-quality steam. The clever bit is, it needs only about 3 percent of the net energy input that standard tech consumes. Not only does this reduce energy demand significantly but the produced steam has value of its own, industries like power plants, cement, steel, and even oil and gas operations can use it, which is pretty handy.

Halliday emphasizes that Mantel’s technology is designed as a sort of plug-and-play solution for existing factories, aiming to minimize disruption. “This is a pragmatic solution,” he says, “fixing the problem as it stands today,” which resonates, especially given how industries worldwide are feeling the pressure from rising carbon taxes and tighter regulations.

Since starting Mantel in 2022, and moving from tiny prototype models to shipping container-sized systems via the MIT-linked incubator, The Engine, the company has made steady strides toward real-world application. One big step is a partnership with Kruger Inc., based in Quebec, to build a next-generation demo plant. That project is slated to kick off operations next year and will run for a couple of years to prove the technology at scale before it’s rolled out more widely on Kruger’s industrial sites.

Aside from testing and validation, Mantel has managed to secure some serious investment to speed things up. In September 2024, Shell Ventures and Eni Next led a $30 million Series A funding round, aimed at expanding Mantel’s molten salt CO₂ capture systems. The funding will support a demonstration project targeting roughly 1,800 metric tons of CO₂ captured annually. Industry insiders say this tech might bring capture costs down to somewhere between $30 and $50 a ton, potentially a game-changer for heavy industries located in regions with high carbon footprints.

The project’s also gotten some government backing. Mantel was awarded a Phase I Small Business Innovation Research (SBIR) grant from the US National Science Foundation to refine the composition of the molten alkali metal borates for better efficiency. That NSF funding focuses on sectors like cement, steel, hydrogen production, and other tough-to-abate industries, those hard-to-decarbonize giants, really, since the push to reduce emissions from these sources is absolutely urgent on a global scale.

Studies supporting Mantel’s approach reveal that these molten salts can absorb large amounts of CO₂ at about 600°C, pretty high temperatures, right? A paper published in Nanoscale confirms both the chemical properties and physical behaviour of lithium-sodium borate mixtures for reversible CO₂ absorption and also their potential use in electrolysis. The science checks out, and the practical side seems promising too.

From a design perspective, Mantel’s modular systems are made to fit into existing industrial setups with minimal fuss. They’re compact and straightforward to integrate, according to technical docs from the company. This ease of installation is crucial because industries tend to resist new tech that requires lengthy downtime or costly retrofitting. Approving new solutions often hinges on that simplicity.

And the implications? Well, many experts believe that the high costs and inefficiencies that have long plagued carbon capture efforts could be mitigated significantly with Mantel’s approach. By turning the process, initially viewed as just waste management, into something that produces valuable steam, the technology might finally convince more industries to get on board. The potential for scalability and widespread adoption in traditionally resistant sectors could, in theory, really move the needle toward achieving net-zero industrial emissions.

Looking at the bigger picture, especially in regions like the UAE, where heavy industry and power generation still contribute heavily to carbon emissions, Mantel’s molten salt method could be a significant breakthrough. It’s designed to work within existing high-temperature processes, offering both economic incentives and environmental benefits, an attractive combination considering regional decarbonization goals and the push towards CCUS (carbon capture, utilization, and storage).

Of course, there are still hurdles, scaling up, creating reliable downstream utilization or storage, and integrating with existing infrastructure are challenges to watch. But with strong academic validation, investor backing, industrial partnerships, and government support, Mantel is positioning itself as a notable player in the evolving carbon management scene. Reflecting on Cameron Halliday’s journey, from early setbacks to pioneering innovations, it’s clear that this molten borate tech, driven by solid science and pragmatic business minds, could have a lasting impact on industrial climate solutions worldwide.

Source: Noah Wire Services