Data and code for: Iron oxide versus ceria in methane-driven solar thermochemical cycles: cyclic steady state, energy accounting and exergy analysis

Data and code supporting the article "Iron oxide versus ceria in methane-driven solar thermochemical cycles: cyclic steady state, energy accounting and exergy analysis" (submitted to Energy Conversion and Management). The archive contains: (i) the NIST-JANAF thermochemical tables used (unchanged); (ii) an open Python Gibbs-energy minimiser for ideal gases + pure condensed phases, verified against Cantera and closed-form Fe-O-H equilibria; (iii) the two-step solar Fe3O4/CH4/H2O cycle model with four energy-accounting levels (incl. pinch-limited heat recovery), cyclic-steady-state iteration and exergy balances; (iv) all results as CSV files (00_INDEX.csv gives the order and purpose of each file, DATA_DICTIONARY.csv the meaning and unit of every column); (v) all figures (PNG 600 dpi and PDF) with the plotted numbers. Running code/run_all.py reproduces every number, table and figure of the article. The manuscript itself is not included. Version 1.1 (after an internal review): pressure sign in the equilibrium dual corrected (no effect at 1 bar), explicit cyclic-steady-state status of every point, reported optima are true maxima, new accounting case B' and pinch-limited heat recovery, solar-exergy efficiency, Gouy-Stodola check of the exergy balance, and supplementary analyses S1-S7 (first cycle vs CSS, window thresholds, inert ZrO2 support, pressure, thermochemical data and wustite, direct solar steam reforming, carbon activity). Files: the archive is provided in four parts that unzip into the same folder Fe3O4_CH4_solar_cycle/: part1 (code, documentation, NIST-JANAF tables and all small result files), part2 (figures and figure data), part3 and part4 (the two large cycle maps P3_cycle1_maps.csv and P4_css_maps.csv, 49 200 rows each). Unzip all four parts into the same directory; then run python code/run_all.py --skip-fetch.