Thermodynamic analysis of liquid hydrogen production by using geothermal-based multigeneration plant

In this paper, a new geothermal energy-based multigeneration plant was designed to produce several valuable outputs, such as electricity, liquid hydrogen, freshwater, greenhouse heating, and cooling. This study aimed to find a solution regarding using fossil fuels to supply valuable products such as electricity, hydrogen, heating, and cooling. In addition, it was targeted to increase the geothermal energy systems’ efficiencies by integrating sub-systems into the geothermal power plant. To achieve the highly efficient multigeneration plant, an organic Rankine cycle, a greenhouse heating plant, a freshwater production plant, hydrogen production and liquefaction plants and a single-effect absorption cooling system were integrated into the injection well of the geothermal power source. Thermodynamic and parametric analyses were performed to evaluate the plant’s performance as well as environmental impact assessment and exergo-environmental analysis are done to see how the designed system operates environmental-friendly. According to the thermodynamic assessment results, the energy and exergy performances of the multigeneration plant were 59.14% and 54.83%, and the total electricity production rate was 1404 kW. Also, parametric analyses revealed that increasing reference temperature, geothermal mass flow rate and geothermal water temperature improved the overall system’s performance. These results imply that by controlling these indicators, the plant's performance can be optimized, leading to increased energy and exergy efficiencies and higher electrical energy production rates.