Simply: Carbon Dioxide can be collected and then electrolyzed, in the presence of "OH", hydroxide, ions to form the liquid fuel and, as in ExxonMobil's "MTG"(r) process, Gasoline raw material, Methanol.
The technology disclosed in this United States Patent, developed and owned by the United States Department of Energy, is thus closely related to similar processes we have already documented for the West Virginia Coal Association that were developed by contractors, such as United Technologies, for our United States Department of Defense.
The difference in the Carbon Dioxide recycling technology developed by USDOE scientist Meyer Steinberg lies in the fact that the "OH" ion, needed to react with the CO2, is derived not from the electrolysis of Water, but from the electrolysis of a solution of Potassium Hydroxide and Potassium Carbonate/Bicarbonate in Water.
That fact has a few important implications perhaps not clearly spelled out by the Brookhaven, NY, National Laboratory's Steinberg.
First: The solution of Potassium by Water, to form the Potassium Hydroxide, KOH, specified by Steinberg, is an aggressive, exothermic reaction that needs no help in getting started or, aside from the addition of new raw materials, in continuing.
And, that reaction generates Hydrogen as a by-product, which could be collected and utilized in other, follow-on and related, processes of Carbon hydrogenation. However, we suppose that, once Steinberg's process is in motion, it will likely be unnecessary to create much more KOH in that fashion, unless it is desired to do so. Subsequent processing seems to regenerate much, if not all, of the original KOH.
Second: KOH solutions are almost ideal, and in some cases are specified, for use in Carbon Dioxide scrubbers. The CO2 passing through reacts with the Potassium Hydroxide to form Potassium Carbonate, and/or Bicarbonate, one supposes, still in solution with Water.
Those solutions dramatically reduce the electrical resistance of Water; and, as a consequence, they dramatically reduce the electrical energy required to reduce, to electrolyze, the solutions into reactive components of Hydrogen, Carbon and Oxygen, that can then be recombined, as in this USDOE process, to form Methanol.