Hydrogen Electrolizers

The need for hydrogen availability ‘in situ’ has led KERN to develop alkaline electrolysers based on standard models of proven, efficient, safe and reliable technology.

Our experience dates back to the year 1985 with the construction of the first water electrolysis equipment to produce hydrogen for a chemical industry in Switzerland. Since then we have built and supplied more than 20 facilities of different production capacities, from 0.2 Nm3/h to 70 Nm3/h, in different countries (Switzerland, Belgium, Germany, Norway, Ireland, Saudi Arabia, Italy, Spain, United States) and for different applications (solar-photovoltaic, chemical industry, research ...).

We have know-how and patents.



The main systems of KERN atmospheric alkaline hydrogen production plants are as follows:

  • Transformer/Rectifier
    Transformer and rectifier convert AC voltage supply into DC current input.
  • Electrolyzer
    The electrolyzer is of the filter press type with bipolar electrodes separated by diaphragms (asbestos-free). Hydrogen gas is generated at the cathode and oxygen gas at the anode.
    The K series electrolyzers developed by KERN have an energy consumption per cell stack as low as 4.3 kWh / Nm3 of hydrogen gas produced, and up to 170 kW per stack. A 500 kW stack is currently being developed.
  • Electrolyte system
    This module consists of two gas separators and the electrolyte recycling system. The electrolyte is recovered in the separators, then cooled and recycled to the cell block.
  • Scrubber
    This system has the following main functions:
    • Eliminate residual traces of electrolyte
    • Cool hydrogen
    • Water input
  • Gas tank
    The gas tank is an intermediate tank installed between the electrolyzer and the compressor or the process / consumption on site.
  • Compressor
    If necessary, a compressor is installed to compress the gas from atmospheric pressure in the gas container to the pressure required for the process or for storage.
  • Deoxo
    The hydrogen produced in the electrolyzer is a very pure gas, saturated with water, and an oxygen content of less than 0.2%. If higher purity is required, oxygen can be removed by catalytic reaction in this system.
  • Dryer
    The dryer dries the gas to reach the required dew point. It consists of twin towers filled with a desiccant that absorbs water.
  • Warehouse
    Gas storage is a backup solution or assurance of gas supply in applications with variable consumption.

All this plant can be containerized (20 – 40 foot cotainer)

Main technical features:

Net production capacity

40-160 Nm3/h

Production capacity range


Energy consumption

4,3 kWh/Nm3

Purity with DEOXO

< 1 ppmv of oxygen

H2O in H2

< 2 ppmv

Supply pressure

10 barg/250 barg


20-40 ft container

Operating temperature


Gas temperature



25% aqueous KOH solution

Water consumption

0,8 l/Nm3

Electrolyzer power

170 kW

Spec Sheet
Download .pdf


KERN develops tailored solutions to meet the technical-economic needs of its customers. Services offered by KERN are:

1.- Engineering and projects:

  • Turnkey projects (EPC)
  • Basic and detailed engineering
  • Auxiliary services

2.- Project management:

  • Technical-economic feasibility studies
  • Management and supervision of Works
  • Purchase management
  • Permits and licenses management
  • Legalization of the plant
  • Start up

3.- Assembly, operation and maintenance of plants

KERN through its technical team, exploits, manages and maintains third-party facilities