Thermodynamic analysis of an integrated salt-based cooling in a multigeneration system with hydrogen and ammonia for sustainable resource utilization

The simultaneous need for cooling, freshwater production, and cleaner energy pathways calls for integrated systems that can recover and reuse resources more effectively than standalone technologies. This study proposes an integrated multigeneration system that couples (Formula presented) endothermic cooling and atmospheric water generation (AWG) with mechanical vapor recompression (MVR), proton exchange membrane electrolyzer (PEME), proton exchange membrane fuel cell (PEMFC), bipolar membrane electrodialysis (BMED), and a direct ammonia-fed solid oxide fuel cell (DA-SOFC). A thermodynamic model was established by combining a transient analysis of the (Formula presented) solution cooled atmospheric water harvesting unit, two-stage batch MVR model for concentration and crystallization, and steady-state electrochemical models for the remaining subsystems, followed by energy and exergy assessments under grid and photovoltaic thermal (PV/T) power supply scenarios. The analysis results show that the system can generate 16.470 kg of harvested water from the atmosphere per cycle, 0.226 kg/h of hydrogen, and 0.674 kg/h of ammonia. The PEMFC and DA-SOFC provide a combined electrical power output of 4.520 kW; however, the modeled electrical demand of the PEME, MVR, BMED and PEMFC feed compression units is 23.880 kW, resulting in a net electrical demand of 19.360 kW. When PV/T is incorporated, the overall energy efficiency increases from 0.241 to 0.486, whereas the exergy efficiency decreases from 0.117 to 0.058. Overall, the study demonstrates the feasibility and strong potential of integrating salt-based cooling with multigeneration technologies for sustainable and efficient water-energy management.