Design and energy evaluation of a stand-alone copper-chlorine (Cu-Cl) thermochemical cycle system for trigeneration of electricity, hydrogen, and oxygen

Abstract

Summary In this article, a new stand‐alone Cu‐Cl cycle system (SACuCl) for trigeneration of electricity, hydrogen, and oxygen using a combination of a specific combined heat and power (CHP) unit and a 2‐step Cu‐Cl cycle using a CuCl/HCl electrolyzer is presented. Based on the self‐heat recuperation technology for the CHP unit and the heat integration of the Cu‐Cl cycle unit, the power efficiency of the SACuCl for 5 prescribed scenarios (case studies) is predicted to achieve about 48% at least. The SACuCl uses the technologies of the dry reforming of methane and the oxy‐fuel combustion to achieve a relatively high CO2 concentration in the flue gas, and CO2 emissions for power generation could be almost restricted by 0.418 kg/kWh. From the aspect of the electricity required for hydrogen production, it is verified that the 2‐step Cu‐Cl cycle system is superior to the conventional water electrolyzer because the CHP process supplies the heat/electricity for Cu‐Cl thermochemical reactions and a thermoelectric generator is connected to the exhaust gas for recovering the power consumption from the compressor and the CuCl/HCl electrolyzer. Finally, the heat exchanger network and the pinch technology are employed to determine the optimum heat recovery of the Cu‐Cl cycle. In case 5 analyzed for the SACuCl, the electricity required for the heat‐integrated 2‐step Cu‐Cl cycle is predicted to dramatically decrease from 4.39 to 0.452 kWh/m3 H2 and the cycle energy efficiency could be obviously increased from 23.77 to 31.97%.

Performance Assessment Study on the Na‐O‐H Thermochemical Water Splitting Cycle for Hydrogen Generation

“…An exergy analysis was carried out by the same authors and the integration of Na-O-H thermochemical cycle with multigeneration systems was also examined [25]. The integration of thermochemical cycles into multigeneration systems is not unique to the Na-O-H cycle, examples can be found in the literature for other cycles [26,27].…”

Parametric analysis and yearly performance of a trigeneration system driven by solar‐dish collectors

“…The building sector is one of the most energy‐consuming sectors, which is responsible for about the 30% to 40% of the overall energy consumption in every country . Trigeneration systems are a sustainable choice for producing heating, cooling, and electricity for the building sector . Solar energy is a renewable and abundant energy source, which is usually used for driving trigeneration or generally polygeneration energy systems …”

“…1,2 Trigeneration systems are a sustainable choice for producing heating, cooling, and electricity for the building sector. 3,4 Solar energy is a renewable and abundant energy source, which is usually used for driving trigeneration or generally polygeneration energy systems. 5,6 In the literature, there are numerous studies that investigate solar-driven or solar-assisted polygeneration systems, usually for building applications.…”

Kinetic and electrochemical analyses of a CuCI/HCl electrolyzer

“…Cobourn and Easton have studied the effect of copper contamination at the cathode of Cu–Cl/HCl electrolyzers. Furthermore, Wu et al have designed and assessed a stand‐alone Cu–Cl thermochemical cycle system for trigeneration of electricity, hydrogen, and oxygen and have economically evaluated a kinetic‐based Cu–Cl thermochemical cycle plant . However, there is an important gap in the knowledge base, in that the kinetics for the nonequilibrium state of the CuCl/HCl cell are not well understood and have not been extensively studied.…”