Researchers focus on by-products of electrolysis

22.07.2024

A new test facility in Zittau aims to demonstrate how the by-products of electrolysis - oxygen and heat - can be used efficiently. The city has now granted planning permission.

The pilot plant, called "LA-SeVe", will be built for 2.7 million euros on the premises of Stadtwerke Zittau (Saxony). The name stands for "Laboratory Plant Sector-Coupled Utilization of PEM Electrolysis Products". According to the Fraunhofer Research Institution for Energy Infrastructures and Geothermal Energy IEG, the electrolyzer will be housed in a container room measuring twelve by two and a half meters. A new transformer station will supply it with electricity.

The heat pump with a maximum thermal output of 105 kW, together with the buffer storage tank, pumps and control technology, will have a five by five meter footprint in an existing hall and will be connected to the electrolyser via a water circuit. The waste heat from the electrolyser's research operation is fed into the city's district heating network via the heat pump.

Goods in demand

The plant is being built as part of the "IntegrH2ate" project. The building permit has now been granted by the city and completion is planned for the beginning of next year.

In this project, the researchers are investigating the coupling between PEM electrolysis, heat pumps and the heating network. "PEM" stands for polymer electrolyte membrane. This only allows specific reaction products to pass through and serves to separate the two electrodes during electrolysis. PEM electrolysers are insensitive to load changes. The researchers therefore consider them to be particularly suitable for hydrogen production using electricity from volatile renewable sources. In the project, the waste heat from the electrolysis is to be upgraded by the heat pump so that it can be used as district heating in the city's supply network. The oxygen from the electrolysis process should also become a sought-after commodity if it is sufficiently pure, as the scientists explain.

The test plant that has now been approved will primarily serve to optimize the plant concept and the efficient coupling of electrolysers and heat pumps in electricity-, heat- or hydrogen-driven operation. Depending on whether the focus is on the use of green surplus electricity, the saving of fossil fuels or the optimal production of hydrogen, the operating mode and operating parameters will change. With the plant in Zittau, the project team is now testing the concepts it has developed in recent years in practice.

Clemens Schneider, project manager at the Fraunhofer IEG, explains: "With our pilot plants, we are creating a test infrastructure to test and qualify industry-related processes." The aim is to test on a pilot plant scale how the by-products heat and oxygen from electrolysis can be optimally treated in dynamic operation. "The pilot plant also provides a platform for testing and qualifying future industry-related processes for manufacturers and operators, such as the methanation of carbon dioxide, closed carbon cycles, tests of compressors for oxygen and hydrogen as well as hydrogen burners and other components for using the main and by-products from PEM electrolysis."

The consortium partners in the project are Linde GmbH and the Fraunhofer IEG with its Zittau site. The Federal Ministry of Education and Research is funding the project with around 19 million euros, with the IEG receiving funding of around 4.2 million euros.

Author: Davina Spohn
Source: Energy & Management Powernews