The key chemistry bit:

The receiver heats a gaseous heat transfer fluid which circulates in a closed loop, delivering the high-temperate process heat to the thermochemical reactor and the thermal energy store. In the reactor, CO2, water vapour, and methane sourced from biowaste are heated with the solar energy over a catalyst which produces a mixture of carbon monoxide and hydrogen known as syngas. This is then piped down the tower to a Fischer-Tropsch unit which converts it into a synthetic crude which a refinery would then process into kerosene for planes, diesel or methanol for ships and trucks, and petrol for cars.

Fischer-Tropsch process