Thermodynamic analysis of the thermochemical hydrogen production based integrated systems

In this thesis, two different multigeneration systems were proposed and thermochemical analyzes were performed. The first system includes Kalina, magnesium-chlorine, single-effect absorption cooling, and Organic Rankin Cycles and hydrogen liquefaction subsystem. The working fluid which heated by parabolic dish collector is first sent to Organic Rankine Cycle and generated power. Then this heat is sent to magnesium-clorine thermochemical cycle to produce H2 and O2. H2 is liquefied and stored. The waste heat is sent to the Kalina cycle to generate hot water for power and domestic use. Finally, the waste heat is sent to single-effect absorption cooling cycle and sent to the cold storage tank for reusing. According to the thermodynamic analyzes, the energy and exergy efficiencies of the combined system were calculated as 54.17% and 50.46%, respectively. The second system includes biomass gasification, Brayton, copper-chlorine, Organic Rankin and Kalina cycles, cascaded refrigeration, drying and hydrogen liquefaction subsystems. Burning biogas generated power in the Brayton cycle. Firstly, the exhaust gas transferred to the copper-chlorine cycle, where O2 and H2 are produced. Power is generated while H2 was liquifying. The waste heat is sent to Organic Rankin and Kalina cycles respectively to generate power. Then used for cooling in the cascade refrigeration system and used in the drying process. The energy and exergy efficiency of the system is 56.71% and 53.59% respectively. Calculations were made using EES (Engineering Equation Solver) program. Key Words: Magnesium-chlorine cycle, copper-chlorine cycle, biomass gasification, solar energy, thermochemical cycle, hydrogen production