Hydrogen will become an important clean energy carrier helping to decarbonize sectors with high CO2 emissions. During the process chain from the production of hydrogen to the purification and compression a lot of waste heat is generated. Our Rotation Heat Pump can utilize this waste heat in various ways.
Electrolysis is the technology of the future for the production of green hydrogen. Renewable energy is used to split water into oxygen and hydrogen. During the electrolysis process, more energy is released through the electrodes than is consumed by the endothermic splitting of the water. As a result, the electrolysis cell heats up and the need for continuous cooling arises. During cooling, the temperature difference within the electrolysis cell should be kept as low as possible. In conventional processes, cooling is done by a fan that dissipates the energy to the environment. In contrast, the rotary heat pump can use the cooling circuit directly as a source and cool it to the required temperature level. The extracted heat is used to raise the temperature of the sink up to 150 °C, opening a wide range of applications.
The following hydrogen production processes also generate waste heat that can be used in the heat pump. For example, after electrolysis, the green hydrogen is completely saturated with water vapor. To increase the purity of the hydrogen and the efficiency of compression, a two-stage gas drying process is added to reduce the amount of gaseous water in the hydrogen. Again, the rotation heat pump can use the mixture of heating and cooling to recover energy.
To make hydrogen storable, the purified hydrogen must be compressed. Compressing hydrogen generates a lot of waste heat. First, the temperature of the hydrogen increases as it is compressed, and second, the compressors must be cooled. We have recognized the potential to use the dissipated heat of the compressor intercoolers. The cooling circuit of the compressors is used by the rotation heat pump as source to raise the sink to the required temperature level.