Thermodynamic simulation of hydrogen and hydrogen-natural gas mixtures in underground storage caverns

Intermediate storages for electrical energy can be established by injecting hydrogen into underground storage caverns. The required compression and expansion of the gas involves a change of state and consequently a change in the temperature of the stored gas. The changes of state will be somewhere between the thermodynamic boundary cases: isothermal process, isentropic process and isenthalpic (or Joule-Thomson) process.

The task in this thesis is to implement an equation of state for hydrogen and hydrogen-natural gas mixtures and use the thermodynamic relations to predict the temperature changes during compression and expansion for an exemplary storage scenario. The calculations can be performed in Matlab, Excel, Python, etc.

• Tietze, V., & Stolten, D. (2016). Thermodynamics of pressurized gas storage. Hydrogen science and engineering: materials, processes, systems and technology, 601-628.