Module-based PEM electrolyzer stack

Researchers of the Westphalian Energy Institute (WEI) at Gelsenkirchen Bocholt Recklinghausen University of Applied Sciences (WH) have developed a pocket-size PEM unit for water electrolysis. The electrolyzer stack is based on the WEI-invented method of hydraulic compression of individual cells [1] through the use of a patented control system [2]. The process allows for an alignment of hydraulic and gas pressure at the start-up of the system to achieve almost any pressure level for hydrogen production. The pressure level required to compress individual stack cells can be kept constant across the entire system, making mechanical component stability the only issue to consider.

New water electrolysis systems should take advantage of the improved direct feed-in of mainly renewable hydrogen into the natural gas grid. By removing the need for additional mechanical compression, the novel design increases overall efficiency and eliminates a wear-prone mechanical component. The result is a reduction in overall system cost. The prototype unit was developed jointly with iGas engineering from Solingen during a publicly funded ZIM project (funding ID: KF2697002ZG3).

WES 2016 showcase

In April 2012, HZwei had already reported about a similar PEM fuel cell stack design that used hydraulic means to compress individual cells instead of the nowadays common mechanical connection of the bipolar cell arrangement. The design served as a good example to demonstrate the benefits of equally distributing pressure across cells and controlling their temperature. This approach has since been used to develop a PEM electrolyzer prototype to provide hydrogen or oxygen at high outlet pressures, for example, for use in power-to-gas plants. It was presented at the World of Energy Solutions in Stuttgart on Oct. 10, 2016.

WEI employees (U. Rost, J. Roth and P. Podleschny; from left) put the screws into the pressure tank, © WH/MV

The prototype includes a high-pressure storage unit with four pockets (see figure 1) and another …

Fully modular PEM electrolyzer with multilayer, planar pole plates

…

References …

Authors:

Professor Dr.-Ing. Michael Brodmann, michael.brodmann@w-hs.de

Dr. Ulrich Rost, ulrich.rost@w-hs.de

Both from Westfälische Hochschule Gelsenkirchen Bocholt Recklinghausen