One of the main challenges currently hindering the transition to energy systems based on renewable power generation is grid stability. To compensate for the volatility of wind- and solar-based power generation, storage facilities able to adapt to seasonal and short term differences in energy production and demand are required. Liquid Organic Hydrogen Carriers (LOHCs) represent a viable method of chemically binding elemental hydrogen, offering opportunities for largescale and safe energy storage. In times of energy shortage, flexible and dispatchable power generation technologies such as gas turbines can be fueled by hydrogen stored in this manner. Hydrogen can be released from its liquid carrier via an endothermic dehydrogenation reaction using waste heat provided by the gas turbine. This gaseous hydrogen can be supplied to the gas turbine combustion chamber using a hydrogen compressor. In the present study a steady state model is developed in order to analyse the heat-integrated combination of a 7.7 MW hydrogen-fired gas turbine and a H18-DBT/H0-DBT LOHC system. For the best-performing parameter set the effective storage density of the LOHC oil comes to 1.5 kWh/L. This value is situated in-between that of compressed hydrogen at 350 bar (1.01 kWh/L) and liquid hydrogen (2.33 kWh/L). Concurrently, the corresponding energy required for hydrogen compression reduces the overall system efficiency to 22.00 % (η_GT = 30.15%). The resulting optimal electricity yield, being a product of these two values, amounts to 0.33 kWhel/L.

To combat climate change successfully, enhancing existing processes is imperative alongside exploring new regenerative technologies. For this purpose, new components must be considered to improve the efficiency of thermodynamic processes. A promising candidate is the Ranque–Hilsch vortex tube due to its low investment cost and maintenance. Previous research has highlighted the thermodynamic advantages of employing a vortex tube in various applications, such as Brayton cycles or as a replacement for conventional expansion valves. However, to assess the potential of the vortex tube within a thermodynamic process, a computationally efficient but precise model of the vortex tube is required. Existing modeling approaches often fail to accurately predict experimental trends or require information such as geometry data that are not available for potential analyses. Thus, the present study proposes a novel thermodynamic-based black-box modeling approach: the vortex tube efficiency is introduced by incorporating operating and geometrical conditions into a single parameter. The vortex tube efficiency is systematically investigated for different operating conditions and various fluids and compared with available experimental results. The resulting modeling approach allows the qualitative and quantitative prediction of vortex tube behavior for air at various operating pressures and cold gas fractions. Further experimental investigations are required for a comprehensive quantitative description of vortex tubes with different geometries and working fluids.