Pilot Plant Technology
A comprehensive look at the 25 kW alkaline electrolyzer system and its integration with renewable energy sources.
System Architecture
The pilot plant consists of a 25 kW alkaline electrolyzer (McPhy Italia) commissioned in 2023. It features a built-in power electronics controller by Unitronics and operates under ATEX safety standards.
The core electrolyte is a 20 wt% NaOH solution. The system is designed to handle power input from both a PV array (connected via DC-AC inverter) and the grid, ensuring continuous operation even when solar irradiance is low.
Production Process
Power Input
Electricity is supplied by a hybrid system of PV arrays and the grid. The AC-DC converter rectifies the current for the electrolyzer stack.
Electrolysis
Water is split into Hydrogen and Oxygen in the alkaline stack. The lye solution is circulated by a centrifugal pump to maintain temperature and concentration.
Purification
Generated gas passes through a deoxo unit and drying chamber to remove moisture and impurities, achieving 99.999% purity before storage.
Balance of Plant (BOP)
- Thermal Management: Heat exchangers and chillers maintain optimal stack temperature (approx. 51°C).
- Gas Separation: Gravity-based catch pots separate liquid electrolyte from the gas stream.
- Control System: A PLC automates valve operation, pressure regulation, and safety shutdowns.
- Water Recovery: Condensate from the drying process is collected and can be recycled.