Applications of solar thermochemistry to fuel production

As was mentioned in the introductory paragraphs, the potential of the sun can be utilized for the production of solar fuels (i. e., solar hydrogen, solar hydrocarbons, alcohols and liquid fuels). Solar thermochemistry can be employed for the conversion of water and waste CO2 into H2 and CO, which are valuable building blocks for the production of synthetic fuels as well as other chemicals. The different pathways are summarized by Graves et al. (2011) in Fig. 20.2.

In the case of solar hydrogen, the technological maturity and the lack of necessary infrastructure do not allow its immediate large-scale application. On the other hand, solar hydrocarbons can play an intermediate role since they are a means of storing solar energy into a medium which has high energy density and can be more easily stored and distributed, using the current infrastructure, and applied in existing vehicles (Graves et al., 2011).

Estimates by the IEA (2010) suggest that CSP facilities could begin pro­viding competitive solar-only or solar-enhanced gaseous or liquid fuels by 2030, while by 2050 CSP could produce enough solar hydrogen to displace 3% of global natural gas consumption, and nearly 3% of the global con­sumption of liquid fuels. This seems a conservative prediction, as actual deployment is likely to be strongly affected by the progress of international oil prices.

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The processes that can be employed for the synthesis of fuels with cap­tured CO2 and solar H2 and CO as precursor reactants are common to the

ones employed for the conventional fossil-based synthetic fuels and other chemicals. Thus all the downstream technology for solar liquid fuels is available.

Updated: August 24, 2015 — 8:01 pm