Temperature gradient → Chemical fuel

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.01 × C.29 · Temperature gradient × Thermochemicalfamily: Thermochemical

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Carnot limit · formula-bound · hard, applies to this route
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c

Steps

1. 01
   Temperature gradient —drives→ Thermochemical redox cycleestablishedclaim record

   thermal → chemical · loss to thermal

   • a redox-active metal oxide (ceria, ferrites) reduced at 1400–1800 K, typically in a solar receiver, and re-oxidised by H₂O or CO₂ at 800–1200 K

   above ~700 K

   refs [1] [2]
2. 02
   Thermochemical redox cycle —produces→ Chemical fuel (H₂, CO, syngas)establishedclaim record

   chemical → chemical

   refs [2]
3. 03
   Chemical fuel (H₂, CO, syngas) —converts into→ Chemical fuelestablishedclaim record

   chemical → chemical

   refs [1]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 2

1. [1]
   A. Steinfeld. Solar thermochemical production of hydrogen––a review (2005)

   Solar Energy 78, 603-615 · doi:10.1016/j.solener.2003.12.012 · crossref ✓ 2026-09-20 · record
2. [2]
   S. Abanades. Redox Cycles, Active Materials, and Reactors Applied to Water and Carbon Dioxide Splitting for Solar Thermochemical Fuel Production: A Review (2022)

   Energies 15, 7061 · doi:10.3390/en15197061 · crossref ✓ 2026-09-20 · record