Solar Thermochemical Production of Fuels

[Abstract] If cost and efficiency targets can be achieved, Solar Thermochemical Plants – occupying a few square kilometers each – can potentially generate substantial quantities of transportation fuels, therefore enabling reductions in imports of foreign petroleum and emissions of carbon dioxide. This paper describes the results of a comparative evaluation of various solar thermochemical approaches for producing chemical fuels. Common to each approach is the concentration of solar and/or other radiant energy so that high temperature heat is provided for thermochemical processes including chemical reactors, heat exchangers and separators. The study includes the evaluation of various feedstock chemicals as input to the Solar Thermochemical Plant: natural gas, biomass and zero-energy chemicals (water and carbon dioxide); the effect of combusting natural gas or concentrating beamed radiant energy from an orbiting platform (e.g., space solar power) as supplemental energy sources that support high plant capacity factors; and the production of either hydrogen or long-chain hydrocarbons (i.e., Fischer-Tropsch fuels) as the Solar Fuel product of the plant.