H2Pro, an Israeli cleantech startup founded in 2019, produces green hydrogen using a membrane-free technology that reduces capital expenditure by half compared to traditional electrolyzers. The company is backed by investors such as Bill Gates' Breakthrough Energy Ventures and ArcelorMittal. H2Pro is planning to build its first factory in Israel that should be able to produce hundreds of megawatts of capacity from 2023. The company claims that its technology will deliver green hydrogen at less than $1 per kilogram before 2030.
Challenges: hydrogen fuel
The electrolysis of water can produce green hydrogen if the electrolysis is powered by renewable energy sources such as solar and wind. Currently, alkaline electrolyzers predominate on an industrial scale.
This type of electrolyzer consists of two half-cells with electrodes separated by a porous septum in the electrolyte. The oxidation and reduction of water are tightly coupled in both time and space, as they occur simultaneously at two electrodes within the same cell.
The porous septum prevents a physical separation between the produced hydrogen and oxygen. The only thing that polarizes the gasses is the current at the electrodes. Therefore, if the electrolyzer is to produce directly compressed hydrogen, it must maintain a perfect balance between the pressures of the two gasses and a perfectly constant current flow to prevent the formation of an explosive mixture.
As a result, this type of electrolyzer is typically employed to produce hydrogen at pressures not exceeding 7 bar. In addition, the power supply of this type of electrolyzers is connected to the grid and therefore cannot be coupled directly to intermittent renewable energy sources such as solar and wind. If large-scale hydrogen production by renewables-driven electrolysis is to become practical, then electrolyzers that can handle the intermittent power inputs that are characteristic of renewables must be developed.
H2Pro Technology
H2Pro employs a revolutionary approach to solve these problems. They decouple these reactions by dividing the process into two steps: first, an electrochemical step that reduces water molecules to produce hydrogen at the cathode and oxidizes the anode, followed by a spontaneous chemical (non electrochemical) step that reduces the anode back to its original state by oxidizing water to generate oxygen simply driven by hot water.
This method eliminates the most expensive and fragile component of an electrolyzer: the membrane.
This revolutionary technique is known as E-TAC (Electrochemical-Thermally Activated Chemical). E-TAC electrolyzers are suitable for high-pressure hydrogen production (greater than 100 bar), cost-effective scaling (reducing the need for compressors), and potentially direct coupling to renewable energy sources. This revolutionary process enables the production of green hydrogen while maintaining high energy efficiency (98.7% HHV) within the reactors and a system efficiency of 95%.