Turnkey system converts CO2 into minerals and clean hydrogen

If we want to reach the Paris Agreement target of capping the rise in the global average temperature to 1.5°C, we must do more than merely cut the carbon emissions from anthropogenic activities. We also need to implement systems for capturing the carbon that’s emitted by production plants. The problem is that most systems today are slow, expensive, energy-intensive and hard to install, meaning adoption is weak and actual performance is disappointing. However, some promising new technologies are emerging that operate at (almost) ambient temperature.

One example is the system invented by DeltaSpark, a spin-off of EPFL’s Laboratory for Energy Materials. It incorporates a number of patented breakthroughs developed with funding from a Bridge Proof of Concept grant and the support of EPFL’s Sciencepreneur status. DeltaSpark’s system turns CO₂ into stable minerals in record time while also producing clean hydrogen. It will be marketed in the form of an easy-to-install, turnkey unit the size of a standard shipping container, at a much lower cost than existing systems.

Several Swiss companies have expressed an interest in DeltaSpark’s technology, in part because Switzerland’s carbon tax of CHF 120 per metric ton of emitted CO₂ is prompting them to look for low-cost, pragmatic solutions. DeltaSpark has additionally been awarded an Innogrant and various types of startup funding.

Ultra-fast mineralization near room temperature with a simultaneous H₂ production

Some of the CO₂ found in the air naturally dissolves in water and reacts with the minerals in rocks, where it’s stored in a stable state for a very long time. This process, which takes place slowly over thousands of years, has inspired engineers and manufacturers looking for a speedier way to turn waste CO₂ emissions into a resource. Electrolysis, for instance, uses electricity to convert CO₂ gas into stable ions that react with metals, accelerating the process of mineral formation.

We are the first solution to address both CO₂ storage and simultaneous H₂ production

DeltaSpark’s system employs electrolysis to enable mineralization at near ambient temperature, at a much faster rate than conventional techniques, while producing clean H₂ at the same time. “We are the first solution to address both CO₂ storage and simultaneous H₂ production,” says Luc Bondaz, one of DeltaSpark’s cofounders. Some of the company’s inventions have been patented, such as the enhanced electrochemical cell and the architecture of the mineralization mechanism.

Useful byproducts offset the cost

“Our system will be sold in relatively compact units that can process two metric tons of CO₂ daily and that can be set up right where emission streams are located, thus cutting carbon carry, capture and storage costs and facilitating integration into existing plants,” says Bondaz. The system breaks CO₂ down into clean hydrogen and solid minerals that plant operators can subsequently use. “On top of not having to pay for carbon storage, plant operators will also get useful reaction products,” he adds. “Carbonate minerals can be employed to make more sustainable building materials, and clean hydrogen is a potential energy source. All that helps offset the cost of the system. We plan to use the funding we’ve raised – including a recent injection of over CHF 600,000 – to develop and build a prototype.”

DeltaSpark’s two founders – Luc Bondaz and Suhas Nuggehalli Sampathkumar – met in 2022 during EPFL’s PhD Excellence Program, which offers PhD students training in leadership and public speaking. The two engineers also benefited from EPFL’s Sciencepreneur status, enabling them to take their technology from the research stage to market while remaining temporarily affiliated with an EPFL lab.

Suhas Nuggehalli Sampathkumar, CTO, holds a PhD in CO₂ and H₂O electrolysis and is an expert in low-temperature electrolysis and fuel-cell technology. Luc Bondaz, CEO, studied carbon capture membranes for his PhD and also holds a master’s in business analytics from Imperial College London. This business training gives him another perspective on the challenges DeltaSpark will face as it expands: “Looking further out – and this is more of a political issue – we’ll have to convince companies to do more than simply avoid paying the carbon tax.”