Steelmaker ArcelorMittal has made a US$5-million investment in H2Pro through its XCarb innovation fund, bringing the fund’s total investment commitments to US$180 million since its launch in March 2021. The investment is part of a US$75-million Series B fundraise by H2Pro, with other investors including Temasek, Horizons Ventures, Breakthrough Energy Ventures and Yara.

H2Pro is developing a new way of producing hydrogen from water. Similar to electrolysis, its technology, E-TAC (Electrochemical – Thermally Activated Chemical)—developed at Technion, Israel Institute of Technology—uses electricity to split water into hydrogen and oxygen. Unlike conventional electrolysis however, hydrogen and oxygen are generated separately in different steps—an Electrochemical step and a Thermally Activated Chemical step.

E-TAC’s membrane-free electrolytic reactors are suitable for high-pressure hydrogen production and cost-efficient scaling. This disruptive process enables the production of green hydrogen in a way that retains high energy efficiency (98.7%HHV) inside the reactors and a 95% system efficiency. Traditional water electrolysis technologies typically deliver energy efficiency of around 70%.

A paper describing the basics of the two-step electrochemical chemical cycle for water splitting was published in the journal Nature Energy in 2019.

Electrolytic hydrogen production faces technological challenges to improve its efficiency, economic value and potential for global integration. In conventional water electrolysis, the water oxidation and reduction reactions are coupled in both time and space, as they occur simultaneously at an anode and a cathode in the same cell. This introduces challenges, such as product separation, and sets strict constraints on material selection and process conditions.

Here, we decouple these reactions by dividing the process into two steps: an electrochemical step that reduces water at the cathode and oxidizes the anode, followed by a spontaneous chemical step that is driven faster at higher temperature, which reduces the anode back to its initial state by oxidizing water. This enables overall water splitting at average cell voltages of 1.44–1.60 V with nominal current densities of 10–200 mA cm⁻² in a membrane-free, two-electrode cell. This allows us to produce hydrogen at low voltages in a simple, cyclic process with high efficiency, robustness, safety and scale-up potential.

—Dotan et al. (2019)

Schematic of alkaline water electrolysis and the E-TAC water-splitting process. (a) In alkaline water electrolysis, which typically takes place at elevated temperatures (50–80 °C)6, the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are coupled in both time and space, as they occur simultaneously at an anode and a cathode, which are placed together in the same cell. A diaphragm or anion exchange membrane separates the anode and cathode compartments and prevents O₂/H₂ crossover.
(b) E-TAC water splitting proceeds in two consecutive steps. An electrochemical step (left) reduces water by the conventional HER at the cathode, liberating hydroxide ions (OH^–) that oxidize a nickel hydroxide (Ni(OH)₂) anode into nickel oxyhydroxide (NiOOH). This step is followed by a chemical step (right), wherein the NiOOH anode reacts with water to spontaneously produce oxygen. The first (electrochemical) reaction occurs at ambient temperature (~25 °C), whereas the second (chemical) reaction proceeds at elevated temperatures (~95 °C) for the optimum rate of reaction. The first and second reactions sum up to the overall water-splitting reaction, 2H₂O → 2H₂ + O₂. Dotan et al.

E-TAC is also expected to prove more cost effective than traditional electrolysis, with CAPEX costs anticipated to be broadly halved, alongside lower operational costs. H2Pro is targeting producing hydrogen at a cost of under US$2/kg by 2023, when its first commercial, megawatt scale project is anticipated to move into production, and at a cost of under US$1/kg by 2030.

The potential green hydrogen holds to deliver deep decarbonization of the steelmaking process is well understood. Although the technology required to directly reduce iron ore using hydrogen still needs to mature, the greater challenge with this new method of ironmaking is the cost and availability of the energy input—green hydrogen.

Given H2Pro’s focus on developing a novel technology which aims to produce green hydrogen in an energy efficient manner at competitive costs, it is a very welcome and natural addition to our XCarb innovation fund investment portfolio. Although at an early stage, E-TAC is a very exciting technology and we look forward to working with the H2Pro team as it seeks to move it into commercial production.

—Pinakin Chaubal, chief technology officer, ArcelorMittal

H2Pro is the fifth investment ArcelorMittal has made through its XCarb innovation fund. The company has previously invested:

• An initial US$10 million in Heliogen, a renewable energy technology company that focuses on ‘unlocking the power of sunlight to replace fossil fuels’, supplemented by a further US$10-million investment at the time of Heliogen’s recent IPO.

• US$25 million in Form Energy, which is developing a breakthrough low-cost iron-air battery storage technology.

• US$30 million in LanzaTech, a carbon recycling company with which ArcelorMittal has a €180-million carbon capture and re-use project underway at its steel plant in Ghent, Belgium.

The company has also committed US$100 million over five years in Breakthrough Energy’s Catalyst program, an initiative Bill Gates founded to scale the technologies the world needs to reach net-zero emissions by 2050.

Resources

• Dotan, H., Landman, A., Sheehan, S.W. et al. (2019) “Decoupled hydrogen and oxygen evolution by a two-step electrochemical–chemical cycle for efficient overall water splitting.” Nat Energy 4, 786–795. doi: 10.1038/s41560-019-0462-7