Mantel’s $50M War Chest Signals New Era for Industrial Carbon Capture

CAMBRIDGE, Mass. – August 24, 2026 – In the world of industrial decarbonization, carbon capture has long been the technology of tomorrow—perpetually promising, yet consistently hobbled by punishing costs and energy penalties. A new strategic investment suggests that tomorrow may finally be arriving. Mantel, a Cambridge-based technology firm, has secured an $18 million funding round led by Constellation Technology Ventures (CTV) and Azimut Investments, bringing its total capital raised to a formidable $50 million.

This is more than a standard venture round; it's a calculated bet by major players in the energy and finance sectors on a technology that claims to fundamentally rewrite the economics of capturing carbon. Mantel is moving to commercialize a novel system designed for the fiery heart of heavy industry—power plants, cement kilns, and paper mills. By targeting the foundational barriers of cost and efficiency, the company is positioning itself not just as a climate solution, but as a viable, and perhaps even profitable, operational upgrade for the world’s most challenging-to-abate sectors.

“This moment is about execution and how fast we can build,” said Cameron Halliday, Mantel’s CEO, in a statement accompanying the announcement. The infusion of capital from partners who, as he noted, “understand large-scale energy infrastructure” is a clear signal that the company is shifting from development to full-scale deployment.

A Bet on Better Economics: The Molten-Borate Breakthrough

For decades, the standard approach to carbon capture has been a brute-force affair. Flue gas, rich in CO2, is cooled and then passed through chemical solvents, most commonly amines. This process works, but it saps a tremendous amount of energy—sometimes up to 30% of a power plant's output—to regenerate the solvents for reuse. This “energy penalty” has been the technology’s Achilles' heel, making it prohibitively expensive for most applications.

Mantel’s innovation, born from research at MIT’s Department of Chemical Engineering, sidesteps this problem entirely. Instead of cooling the gas, Mantel’s system embraces the heat. It uses a proprietary liquid-phase material—molten borates—that operates at the same high temperatures as industrial exhaust streams. The technology integrates directly into a facility’s boiler or furnace, capturing CO2 while simultaneously recovering waste heat to generate high-quality steam. This transforms the energy penalty into an energy dividend.

The company’s claims are striking: a 97% reduction in energy losses compared to conventional systems and an operating cost of less than half the industry average. At scale, Mantel is targeting capture costs below $50 per tonne of CO2. This figure is critical, as it falls well below the financial incentives offered by policies like the U.S. Inflation Reduction Act, turning a compliance cost into a potential revenue stream. The process also solves the durability issues that have plagued high-temperature solid sorbents, which tend to degrade quickly, by using a stable liquid medium.

From Lab to Large-Scale: The Commercial Proving Ground

With $50 million in the bank, Mantel is now focused on proving its technology in the field. The company is already advancing a portfolio of projects that serve as crucial testbeds for its commercial ambitions across North America.

In West Virginia, Mantel has been selected as the carbon capture partner for the ambitious 1.6-gigawatt TerraSpark Energy Campus. This greenfield project aims to build a coal-fired power plant with 98% emissions capture from day one, a venture supported by federal funding for its initial engineering and design phase. Success here would provide an undeniable blueprint for abating emissions from fossil fuel-based power generation.

In Québec, the company is deploying its first operational unit inside Kruger’s Wayagamack Mill, a major pulp and paper facility. This demonstration project, expected to capture over 2,000 tonnes of CO2 annually starting in 2026, is a world-first for the industry. Crucially, the captured CO2 will be purified and reused directly in the papermaking process, showcasing a circular model for carbon utilization.

Furthermore, Mantel has initiated an engineering study with a major, though currently unnamed, Canadian oil and gas producer to integrate its system into steam-assisted gravity drainage (SAGD) operations. The project is designed to capture 60,000 tonnes of CO2 per year while generating 150,000 tonnes of high-pressure steam, demonstrating its applicability in the oil sands—one of the world's most scrutinized sectors for emissions.

The Strategic Calculus of Big Energy and Global Finance

The identities of Mantel’s new investors are as significant as the technology itself. The investment from Constellation Technology Ventures represents a major vote of confidence from the United States' largest producer of clean energy. While known for its massive fleet of nuclear, hydro, and renewables, Constellation’s backing of a point-source capture technology signals a pragmatic acknowledgment that decarbonizing heavy industry requires a diverse toolkit. It reflects a strategy to support practical solutions that can be integrated into existing infrastructure without compromising grid reliability.

“Our investment in Mantel’s technology exemplifies our interest in practical, clean-energy solutions, while balancing sustainability and reliability,” noted Kate Norman, Senior Vice President at Constellation. This move aligns with the energy giant's goal of achieving a 100% carbon-free electricity supply by 2040, a target that will require solutions for both new clean generation and the abatement of remaining emissions.

The participation of Azimut Investments points to Mantel’s global ambitions. As the company looks to expand beyond North America, access to international capital markets and project finance expertise will be essential. Azimut provides a strategic bridge to Europe and other geographies where carbon pricing and industrial decarbonization mandates are creating fertile ground for cost-effective technologies.

Riding the Policy Wave: A Market Primed for Capture

Mantel’s emergence is perfectly timed with a seismic shift in public policy. The global market for Carbon Capture, Utilization, and Storage (CCUS) is projected to grow from around $5 billion in 2025 to over $30 billion by 2035, driven by a powerful confluence of regulatory pressure and financial incentives.

In the United States, the Inflation Reduction Act of 2022 supercharged the 45Q tax credit, offering $85 for every tonne of CO2 captured and permanently sequestered. In Canada, a rising federal carbon price—set to hit C$170 per tonne by 2030—is complemented by a generous CCUS Investment Tax Credit. These policies have fundamentally altered the business case for carbon capture. For a technology like Mantel’s, with a claimed capture cost below $50 per tonne, the arbitrage opportunity is clear and compelling.

By solving the core economic and engineering challenges that have long plagued CCUS, Mantel is not just developing a new piece of equipment. It is creating a platform that allows heavy industry to navigate the energy transition without sacrificing competitiveness. This convergence of breakthrough technology, strategic capital, and robust policy support is creating the conditions for carbon capture to finally move from the periphery to the center of the world's decarbonization strategy.