Integrated thermochemical Mg‐Cl‐Na hydrogen production cycle, carbon dioxide capture, ammonia production, and methanation

Abstract

Summary The surge in greenhouse gases and concerns regarding global warming is at the focal attention in today's environmental issues. Many solutions are put through to counter this, toward which carbon dioxide‐capturing methods are promising in reducing the carbon footprint. It is commonly agreed that carbon capture is a leap forward in eliciting vast cuts in greenhouse gas emissions and at the same time still utilizing fossil fuels with the conventional energy infrastructure. This study proposes a novel integrated carbon‐capturing system for flue gases emitted from industrial sources, with a thermochemical Mg‐Cl‐Na cycle as the driving force, coupled with ammonia and methanation production units, as reliable energy carriers. The proposed system is thermodynamically analyzed and a sensitivity and exergy analysis is implemented. The proposed system feeds on 1244 kg/h of flue gasses, which is converted to 7.2 kg/h of ammonia and 20.37 kg/h of methane. The sensitivity analysis is implemented so as to attain the effect of conversion factor on rates of production, endothermic, and exothermic reaction heat duties, and CO2 absorption. Further, the results indicated energy and exergy efficiency of 16.9% and 33.7% for the system, respectively. Highlights A novel carbon capture cycle integrated system with thermochemical Mg‐Cl‐Na impetus is proposed Ammonia and methanation production units are inaugurated as reliable hydrogen carriers Thermodynamic analysis corroborated a 16.9% efficiency for the proposed integrated system Exergy analysis indicated a 33.7% exergy efficiency for the integrated systems, underscoring the precipitation reactor of having the largest share of total exergy destruction

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].…”