Production of solar CO via two-step neodymium oxide based thermochemical CO2 splitting cycle

Detailed thermodynamic scrutiny of the solar thermochemical neodymium oxide-based CO2 splitting (Nd-CS) cycle is reported. The thermal reduction (TR) and CO2 splitting (CS) reaction temperatures required for the operation of the Nd-CS cycle were determined. The equilibrium compositions of Nd2O3, NdO, and O-2 exhibit that the initiation of the TR of Nd2O3 is feasible at 1982 K, and the complete conversion is possible at 2232 K. As per the delta G analysis, the CS reaction was feasible at all temperatures above 300 K. After understanding the chemical thermodynamic equilibrium of the Nd-CS cycle, the efficiency analysis was performed by using the HSC Chemistry 9.9 software. The results obtained via the efficiency analysis shows that the Nd-CS cycle was capable of attaining the highest possible eta(so)(lar)(-to-fuel-Nd) = 9.45% at partial TR of Nd2O3 = 55% (T-H = 2154 K). Application of HR = 20%, 40%, 60%, 80%, and 100%, improved eta(solar)(-to-fuel-Nd-CS) at TR-Nd = 55% (T-H = 2154 K) up to 10.51%, 11.84%, 13.55%, 15.85%, and 19.09%, respectively.