Mehmet F. Orhan

Energy and exergy analyses of the drying step of a copper-chlorine thermochemical cycle for hydrogen production

Hydrogen can be produced by decomposing water, through thermochemical cycles, in an environmentally benign manner using nuclear energy. The copper-chlorine (Cu-Cl) cycle is one of the most promising low-temperature thermochemical cycles and involves five main steps: HCl (g) production; oxygen production; copper (Cu) production; drying; hydrogen production. In this study, energy and exergy analyses are performed of the drying step of the Cu-Cl cycle for hydrogen production, considering its operational and environmental conditions. The evaluation considers efficiencies and various parametric studies are carried out of energetic and exergetic aspects, considering variable evaporator and reference-environment temperatures.

Simulation and Exergy Analysis of a Copper–Chlorine Thermochemical Water Decomposition Cycle for Hydrogen Production

In this study, a simulation model is developed to design and analyze a five-step Cu–Cl cycle using the Aspen PlusTM chemical process simulation package. Based on the developed simulation results, an exergy analysis is conducted of a Cu–Cl cycle and its relevant chemical reactions. The reaction heat, exergy destruction, and efficiencies for each chemical reaction vary with the reaction temperature and reference-environment temperature. Energy and exergy parameters and the yield effectiveness are examined for the process, based on five-step cycle. The overall energy efficiency of the cycle varies from 42 to 44 % and exergy efficiency from 72 to 75 %. Sensitivity analyses are performed to determine the effects of various operating parameters on the efficiencies and yields. A parametric study is conducted and possible efficiency improvements are discussed.

Environmentally Benign Nuclear-Based Hydrogen Production

Energy is a mainstay of an industrial society. It is, therefore, not surprising that many important organizations have attempted to analyze the future need for energy and the availability of various energy sources. Energy consumption growth is closely linked to population growth, although changes in life styles and efficiency improvement have a substantial influence on the per capita annual consumption. The structure of population and the share between urban and rural populations also affect energy demand (Torjman and Shaaban, 1998).