Performance assessment of solar-based integrated Cu–Cl systems for hydrogen production

• Energy and exergy analyses of integrated solar heliostat-based Cu–Cl systems.
• Parametric studies to investigate effect of different operating parameters.
• Comparative study to show which system performs better.

The present study analyzes two integrated systems for hydrogen production, namely, (a) integrated solar heliostat, Cu–Cl cycle and Kalina cycle system and (b) integrated solar heliostat, Cu–Cl cycle, Kalina cycle and electrolyzer system. The systems operating parameters, such as, solar radiation intensity, mass fraction of hydrochloric acid and ambient temperature are varied to investigate their effects on hydrogen production rate by both systems, amount of hot water required by the Cu–Cl cycle, amount of water required at state cc[1] and energy and exergy efficiencies of the systems. A comparative study is also carried out to compare the effects of operating parameters on the hydrogen production rate and energy and exergy efficiencies of both the systems. The results show that the system 2 produces 297.7 L/s of hydrogen as compared to 289.4 L/s produced by the system 1 at a solar light intensity of 1200 W/m2. It is also found that the system 1 performs 2.15% and 3.36% better than the system 2 from energy and exergy perspectives, respectively when solar light intensity is varied. From energy and exergy perspectives, the system 1 performs 1.92% and 2.91% better than the system 2, respectively with variation in the mass fraction of hydrochloric acid. The results show that energy efficiency is not affected by the increase of ambient temperature while the corresponding exergy efficiency increases considerably.