6E analyses of a new solar energy-driven polygeneration system integrating CO₂ capture, organic Rankine cycle, and humidification-dehumidification desalination

Integrated solar-assisted polygeneration systems have emerged as an effective and sustainable alternative for meeting thermal, power and freshwater demands through decentralized generation. In this framework, this study introduces a new design and dynamic simulation approach to a solar energy-driven polygeneration system integrating gas and steam turbine cycles, organic Rankine cycle (ORC), CO₂ capture, and humidification-dehumidification (HDH) desalination. The integrated system is designed to supply a greenhouse's power, freshwater and carbon needs. The proposed system is modelled and dynamically simulated via MATLAB software, and the results are validated by literature data and THERMOFLEX software with high accuracy. A comparative study is conducted to evaluate the feasibility of integrating solar thermal energy, in which process simulations are carried out with and without the solar energy field composed of parabolic trough collectors. Sensitivity analysis is used to determine the optimal operating conditions of the HDH system and the ideal ORC working fluid. Furthermore, comprehensive Energy, Exergy, Exergoeconomic, Exergoenvironmental, Emergoeconomic, and Emergoenvironmental (6E) analyses are performed for scenarios with and without the solar energy field. The results reveal that solar energy integration boosts ORC's power generation from 37.3% (winter) to 59.41% (summer), while the overall power production increases 18 kW compared to the base case scenario. Finally, the system revenues and the payback period are estimated at 50k US$/year and 4.67 years, respectively.