4Diversifying Solar Fuels: A Comparative Study on Solar Thermochemical Hydrogen Production Versus Solar Thermochemical Energy Storage Using Co3O4
Atalay Calisan and Deniz Uner*
Middle East Technical University, Faculty of Engineering, Chemical Engineering Department, Universiteler Mahallesi Dumlupinar Bulvari Cankaya, Ankara, Turkey
Abstract
A comparative analysis is provided for hydrogen production from concentrated solar energy versus storage of the solar thermal energy in the form of reduced state of cobalt oxide, which can be oxidized, whenever and wherever needed. Based on the data published in the literature so far, as well as the data generated in this study, it was demonstrated that, unless the chemical looping oxide is not reduced to the metallic state, or to a state where oxygen is permanently bound to the metal, hydrogen production is limited to a few mmole/g oxide. The residual oxygen in the oxide and hydrogen interaction is inevitable, simply because of the thermodynamic constraints of water splitting reactions. On the other hand, storage and transport of thermal energy in the form of stoichiometric or nonstoichiometric oxides is highly efficient, as demonstrated through the CoO/Co3O4 cycle.
Keywords: Hydrogen, thermochemical process, oxygen exchange, solar energy storage
4.1 Introduction
Storage of solar energy through thermochemical processes are very promising alternatives for several reasons. First and foremost, it is theoretically possible to utilize full ...
Get Solar Fuels now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
