High temperature solar thermochemical process for production of stored energy and oxygen based on CuO/Cu2O redox reactions. (1st September 2017)

• Record Type: Journal Article
• Authors: Haseli, Pegah; Jafarian, Mehdi; Nathan, Graham J.
• Is Part Of: Solar energy. Volume 153(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-09-01
• Subjects: Solar energy -- Energy storage -- Oxygen production -- Air separation -- Reduction and oxidation; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2017.05.025
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: A high temperature solar thermal energy storage system is presented. The system employs CuO/MgAl2 O4 oxygen carrier particles as storage medium. The particles are used for chemical and sensible thermal energy storage. Partial pressure of oxygen is employed as the driving force for the reactions. Oxygen is also produced as a valuable by-product. Abstract: A novel solar chemical looping air separation (Sol-CLAS) system is proposed here, in which oxygen carrier particles, composed of CuO as the active ingredient and MgAl2 O4 as the inert support, are employed to provide both solar thermal energy storage for power generation and to separate oxygen from air. The process has been simulated using codes developed in MATLAB and Aspen Plus software for the average diurnal solar insolation of Port Augusta, South Australia. The simulation predicts that 1000 °C can be achieved in both the solar reduction and oxidation reactors, whose identical temperature results in low exergy destruction. A net cycle efficiency of 46% is predicted with the oxygen co-product of 0.023 m 3 /MJ of input solar energy. The calculations also show that 81% of the total input solar energy to the system is stored as combined chemical and sensible heat in the oxygen carrier particles. The required enthalpy of reaction is 26% of the net absorbed input solar energy which is stored as chemical heat in the particles and consequently used for oxygen production. The variations of temperature and composition in different flow streams, total flow rate of oxygen produced per day, the amount of particles stored in the tanks, together with the fraction of sensible and chemical storages are also reported. Also reported is the sensitivity to the effects of main operating parameters of reservoir temperature and conversion of particles are also reported.