About Conventionnal Electrolyzers

Conventional water electrolysis technologies (alkaline, PEM, AEM, high-temperature) all rely on the same operating principle: electricity and water are supplied simultaneously to split water molecules, generating both oxygen and hydrogen gases, while hydrogen must then be compressed and stored under pressure.

This approach comes with several major limitations:

• the need to carefully separate the two gases using a dedicated separator, which adds cost and complexity and drastically limits operating flexibility
• the need to store hydrogen in a costly, operationally demanding, and highly regulated pressurized form

Elhytec Process

Elhytec has developed an innovative alternative to conventional water electrolysis by separating gas production into two successive steps, thanks to the use of an intermediate zinc-based vector:

• First stage: under electrical current, oxygen gas (a by-product) is released, but hydrogen is not produced as gas. Instead, it accumulates as protons in the water. This is a storage phase with no gas, no pressure, at ambient temperature.
• Second stage: without any energy input, a catalyst triggers the release of hydrogen gas on demand. The system then automatically returns to its initial state, ready for the next cycle as soon as electricity becomes available.

Process Advantages

• Competitiveness (no separator required)
• Safety (no coexistence of oxygen/hydrogen, no pressure)
• Flexibility (electrolysis fully tolerant to intermittency or stop-and-go operation)
• Sustainability (no emissions, closed-loop cycle)

Process Implementation

Beyond the intrinsic advantages of the process, the implementation choices introduce two key features:

• adaptation of an existing industrial device to quickly benefit from economies of scale
• the ability to size independently the three core parameters:
  equivalent stored hydrogen capacity, electrical power for recharge, and on-demand hydrogen output flow rate