Concentrated solar energy for thermochemically producing liquid fuels from CO₂ and H₂O

摘要

A two-step solar thermochemical cycle for producing syngas from H₂O and CO₂ via Zn/ZnO redox reactions is considered. The first, endothermic step is the thermolysis of ZnO to Zn and O₂ using concentrated solar radiation as the source of process heat. The second, non-solar, exothermic step is the reaction of Zn with mixtures of H₂O and CO₂ yielding high-quality syngas (mainly H₂ and CO) and ZnO; the latter is recycled to the first solar step, resulting in net reactions CO₂ = CO+0.5O₂ and H₂O= H₂ +0.5O₂. Syngas is further processed to liquid fuels via Fischer-Tropsch or other catalytic reforming processes. State-of-the-art reactor technologies and experimental results are provided for both steps of the cycle.