ELCHPEM2.0: Electrochemical compression of hydrogen

The main objective of the ELCHPEM2.0 project is to further develop and test a novel reactor for the electrochemical compression of hydrogen. The compression takes place in a reactor design developed by project partner ProPuls GmbH with hydraulic pressing. This enables homogeneous pressing in the cells, efficient temperature control and a reduction in mechanical stress on the sensitive cell components. The reactor design is to be further developed within the project to achieve higher pressure stages and greater efficiency. The fully modular functional model for hydrogen compression is intended to achieve outlet pressures of up to 300 bar across several compression stages.

The pole plates account for a large part of the total weight in electrochemical reactors and also make up a significant proportion of the stack costs. A key objective of the project is therefore to develop a cost-effective and high-performance pole plate based on a polymer-graphite composite. Polymer-graphite composites produced using the powder-to-roll process patented by Fraunhofer UMSICHT offer advantages in terms of cost, weight and volume thanks to the continuous manufacturing process and flexible design. However, high mechanical stability combined with high electrical conductivity is also required, especially for use in electrochemical compressors. In the ELCHPEM2.0 project, the composite from the powder-to-roll process is being adapted to the requirements profile for the use of pole plates in an electrochemical compressor and integrated into the new reactor design.

Due to its low volumetric energy density, hydrogen must be compressed to high pressures for many applications. Mechanical compressors (e.g. diaphragm compressors) are typically used for this purpose. Due to their moving parts, compressors are generally maintenance-intensive:  Lubricants are often used, which reduce the required purity of the hydrogen. In addition, their use in residential areas is unattractive due to the noise they generate.

Thanks to their specific design and mode of operation, electrochemical compressors are expected to be more efficient and durable than conventional mechanical compressors. The functionality of electrochemical compressors has already been proven, but no marketable series product is available yet.

• Integration of cost-effective composite electrode plates into the reactor design with hydraulic pressing
• Construction of a prototype reactor for the electrochemical compression of hydrogen with a pressure stage of 100 bar
• Realization of electrochemical hydrogen compression via three pressure stages to 300 bar

• Obitronik GmbH
• ProPuls GmbH
• Westphalian University of Applied Sciences Gelsenkirchen