BMW Group and PSA Peugeot Citroën create JV on hybrid technologies; focus on standard components and open platform
Hyundai introduces Korea’s first CNG hybrid bus

HyET BV achieves single-stage 400 bar electrochemical hydrogen compression

The Netherlands-based HyET BV (Hydrogen Efficiency Technologies), has achieved a milestone in electrochemical hydrogen compression, reaching for the first time a single-stage pressure increase of more than 400 bar.

Building on this promising result, the Netherlands-based company now plans to develop hydrogen purifiers and compressors for several automotive and industrial applications. HyETs hydrogen compressor contains no moving parts, can be produced at low cost, in high volume and is three times more efficient than existing mechanical compressors.

In general, electrochemical cells feature a ion-conductive membrane sandwiched between two reactant chambers. At one side of the membrane a hydrogen-containing molecule (e.g., water or molecular hydrogen) is converted to form protons, electrons, and optionally other gases, using a catalytic material. The protons are transported through the membrane, while the electrons are removed through an electrode present on the membrane.

The electrons are passed through an external circuit, and fed to an electrode present on the other side of the membrane where they react with protons, and optionally other components like oxygen, to form molecular hydrogen, water, or other compounds, depending on the application.

Electrochemical hydrogen compression. Source: HyET BV. Click to enlarge.

Electrochemical cells can also be utilized to pump and compress hydrogen from one side of a cell to another. By applying an electric potential between the electrodes in this type of electrochemical cell, hydrogen is catalytically dissociated at one electrode (anode) to produce two protons which pass through the membrane to the second electrode of the cell (cathode), where they are rejoined by two electrons to form a hydrogen molecule again. The electrochemical compression of hydrogen consumes DC power.

HyET says that its working principle offers the potential of reaching 700 bar or more.

An electrochemical hydrogen compressor offers advantages compared to a mechanical compressor:

  • It is highly efficient due to the practically isothermal process that is used.

  • It is a silent, solid state device without moving parts and with low maintenance requirements.

  • Instead of contaminating hydrogen with trace lubricants, as is often the case with mechanical compressors, electrochemical hydrogen compression will purify the hydrogen feed stream.

Despite these advantages electrochemical hydrogen compression has until now found limited practical use. Efforts by other research groups in the past have proven that is difficult to reach single-stage pressure increases of more than 100 Bar using conventional materials and construction principles.

The new materials and designs developed by HyET now allow much higher pressure levels for the first time.

In the last three months we have managed a tenfold increase in the compressor’s performance. At this rapid rate of development we are confident that HyET will raise the Bar in hydrogen compression even further.

—Head of Process Design Wiebrand Kout

HyET develops high pressure electrochemical hydrogen compressors suitable for use in hydrogen filling stations, electrolyzers and hydrogen home refuelers. When coupled to a natural gas reformer or bio-hydrogen generator, HyETs technology can simultaneously purify and compress the hydrogen gas. Part of this research portfolio is the technology to compress hydrogen electrochemically “on-board” a hydrogen vehicle. This “self- filling tank” can partially regain the compression energy if the polarity is switched when hydrogen flows out of the tank.



So, some electrochemical hydrogen compressor membrane has low pressure on one side and 400 bars(~400 atmospheres) on the other.

That's some membrane!!

This “self- filling tank” can partially regain the compression energy if the polarity is switched when hydrogen flows out of the tank.
Giving two conversions from molecules to ions and back.

I'm sure it would be much more efficient to run the main fuel cell at full tank pressure, which would increase the H+ concentration at the anode and boost the voltage.


For those like me who are not technically educated and to save them looking it up, 700bar equates to about 10,000psi, the pressure used in the Toyota Fuel cell SUV to give it a range of 431 miles.
The previous version was only 5,000psi giving half the range.


This is prolly why we are seeing alot more work on h2 recently. It seems one or more companies may jump the gun and put out cars very soon.


From the last link I had not realised that fuel cell vehicles still cost around £424k each, or that they still used so much precious metals.
Hopefully Hyundai and Toyota are ahead of GM in these respects, as from the information given there I would not expect widespread sales before 2020.


Not exactly dave.. that was the old stack gm transitioned to the new stack just recently so has no cars running on it yet. It would be in the 125k range now.. and the stack after that for 2015-2018 timeframe is likely in the 25000 range or lower. still yes it looks like gm is a little behind honda and some of the others...

Henry Gibson

Now they can develop a CO2 ionic compressor to store a tank of liquid CO2. They could also forget the fuel cell entirely and use the INNAS NOAX free piston engine in the HCCI mode on hydrogen with a hydraulic hybrid vehicle. A TURGO turbine operating from high pressure oil can generate any electrical energy needed. Water can be collected from the engine and used with heat to produce hydrogen. Perhaps they can also make an oxygen membrane. ..HG..


Henry I think they already have versions of O membranes from small commercial and up in widespread use in industry including welding shops employing ~ <10 persons.

To be able to effectively store CO2 forsafe disposal or reuse would be good for green vehicles with application to many fuel and engine types s well as other fossil fuel CO2 mitigation uses.

The comments to this entry are closed.