Mantel

Mantel is a carbon capture technology developer based in Cambridge, Massachusetts, spun out of MIT's Department of Chemical Engineering. The company builds point-source CO2 capture systems based on molten borate salts that operate at the high temperatures found inside boilers, kilns and furnaces. Because the absorption of CO2 by the molten material releases high-grade heat that can be recovered to raise steam or be recycled into industrial processes, the system is designed to reduce the parasitic energy load that burdens conventional amine-based capture. The materials are liquid rather than solid, which the company says avoids the rapid degradation historically associated with high-temperature separation media.

The company targets high-emitting sectors including power generation, oil and gas, pulp and paper, cement, steel and chemicals, and is technology-agnostic with respect to downstream CO2 sequestration or use. Its stated performance goals include reducing energy losses by up to 97%, producing CO2 streams of greater than 99.9% purity, and reaching capture costs below $50 per metric ton at scale; these are company-reported figures that have not yet been validated through sustained commercial operation. Mantel uses a modular, systems-engineering design intended to lower capital intensity and allow installation into existing plants without disrupting operations.

Mantel has progressed from lab-scale demonstration of roughly half a tonne of CO2 captured per day toward larger prototypes and first industrial installations, and has assembled a project pipeline in the United States and Canada.

Founding story

The underlying material science emerged from the Hatton Research Group at MIT, where Professors T. Alan Hatton and Takuya Harada worked with Cameron Halliday. Beginning in 2018 the team screened high-temperature solids for carbon capture, seeking materials that degraded less over repeated absorption cycles. A sodium borate sample showed unexpected reaction kinetics, which the researchers eventually attributed to the material being molten, giving it properties distinct from the solids typically used and unusual stability at high temperature. Mantel was founded in 2022 by Cameron Halliday, Danielle Rapson (also referred to as Danielle Colson, COO) and Sean Robertson (CTO) as a spin-out from MIT's Department of Chemical Engineering.

Business model

Mantel supplies its carbon capture technology to industrial and power-sector operators, integrating its molten-borate systems into customers' existing plants through engineering studies, demonstration installations and commercial-scale projects.

Traction

Mantel demonstrated carbon capture at lab scale of half a tonne per day and planned a demonstration project approximately ten times larger, rated at 1,800 tonnes of CO2 per year. It has been selected as the carbon capture technology partner for the 1.6-gigawatt TerraSpark Energy Campus in West Virginia, a U.S. Department of Energy-supported project integrating capture into a large coal-fired power plant. In Canada, it is developing a front-end engineering and design study for a steam-assisted oil-recovery operation at a major oil and gas producer expected to capture 60,000 tonnes of CO2 annually, and plans an installation at Kruger's Wayagamack mill in Quebec expected to capture approximately 2,000 tonnes annually, which would be its first operation inside a commercial industrial facility.

Latest developments

In August 2026 Mantel announced an $18 million strategic investment led by Constellation Technology Ventures and Azimut Investments alongside existing investors, taking total funding to $50 million and funding commercial deployment across power generation, oil and gas, and pulp and paper. Related developments include a partnership with Aalborg CSP to modularize molten salt carbon capture, and CEO Cameron Halliday's participation in Eni Next Day 2026 in Italy.