Abstract
The thermochemical copper-chlorine (Cu-Cl) cycle is a promising method of clean hydrogen production that involves three primary steps (hydrolysis, thermolysis and electrolysis) for the splitting of water into hydrogen and oxygen. The Cu-Cl cycle has been extensively examined in relation to nuclear based hydrogen production. This study explores potential diversification of the Cu-Cl cycle with other applications, particularly through integration with a petrochemical refinery, where demand exists for both oxygen (e.g., for oxy-combustion) and hydrogen (e.g., for hydrogenation processes) [1].
Where some refineries already integrate a steam Rankine cycle for local power and heat generation, this study further investigates the option of integrating a Cu-Cl cycle with a steam Rankine that serves a petrochemical refinery, with a flowsheet designed to increase the heat recovery and overall system efficiency. The generated oxygen is a feedstock for a cleaner oxy-combustion processes within the refinery, with environmental and energetic benefits, as it facilitates a direct carbon dioxide extraction. Hydrogen can be partially or totally used within the refinery for hydrogenation processes and producing refinery fuels, thereby bringing additional environmental benefits.
The study found that the hydrolysis process can be improved by staging the reactors, with the second stage being a fluidized bed. Application of oxyfuel combustion in the refinery is beneficial with the potential of direct carbon dioxide capture, while energizing thermolysis and hydrolysis units of operation in the Cu-Cl cycle. Integration of a steam Rankine cycle with the Cu-Cl cycle, oxy-fuel combustion loop and the petrochemical refinery was found to be beneficial as it facilitates better heat recovery and local power generation. The availability of cleaner hydrogen for petrochemical hydrogenation processes reduces fossil fuel usage and corresponding CO2 emissions.
Biography
Dr. Greg Naterer is the Vice-President, Academic and Research, and a Professor of Sustainable Design Engineering, at the University of Prince Edward Island in Charlottetown, Canada. His research interests include sustainable energy systems, heat transfer and thermodynamics, including over 300 journal articles, 4 books, and 6 patents in these fields.