The CO2 extraction scheme is close to the holy grail of sustainable fuels, but I have to wonder: is the electrolytic method any more efficient than using e.g. waste heat from a higher-temperature electrolysis cell to dissociate KHCO3 directly? I had the figures at one time but don't remember if I saved the links, and Google has changed its formats again and broken the Scroogle scraper.

As a denier I would say that the cost of electronics has dropped steadily because of Moore's Law ie the halving of feature sizes for integrated circuit manufacturing because of continual improving lithography on an 18 month cyle.

Battery manufacturing is not governed by Moore's Law.

Extracting CO2 at 385ppm will take a lot of energy. More likely it's better to locate a liquid fuel refinery adjacent to a coal fired plant and use its CO2 stream.

Mike, thanks for this detailed piece; these comments are great! So we (Scott Elrod, Matt Eisaman, and Karl Littau) took the time to respond here under our company Twitter account (@parcinc):

@Engineer-Poet -- Because the electrodialytic approach does not require heating the entire solvent mass to extract the CO2, relative to thermal regeneration, electrodialytic regeneration has an increasing advantage for solvents and gas streams with high binding energies and low CO2 loading (the amount of dissolved CO2 it is possible to "load" into the solution). Relative to flue-gas capture, the capture of CO2 directly fom the atmosphere necessitates the use of capture solvents with high binding energy, and the low concentration of CO2 in the atmosphere results in relatively low CO2 loading, giving electrodialytic separation more of an advantage in this case.

@Mannstein We completely agree that battery manufacture isn’t governed by Moore’s Law. The emphasis on making finer geometric structures in batteries is not meant to be similar to the “transistor shrink” associated with successive semiconductor technology nodes. Rather, it is a very specific geometrical approach to alleviate the limitations on Li ion transport in the cathode material. Unlike Moore’s Law (which benefits from ever finer features), the fine segmenting of battery electrodes will reach a point of diminishing returns. Still, we expect the optimally-sized structures to result in a battery with a higher energy capacity than a conventional Li-ion battery.

@HarveyD There will indeed be specific “learning curves” associated with different battery performance parameters. The learning curve for microelectronics -- Moore’s Law -- is enabled by two primary factors: wafer size increase, and photolithography feature size decrease. Moore’s Law is the fastest learning curve anywhere in manufacturing. While substrate size for batteries might increase somewhat, the substrates are alreasy quite large (i.e., roll-to-roll systems). And there is no analogue to the photolithography shrink associated with batteries (or solar, or fuel cells). So the learning curves for batteries will likely be much more gradual.

@Reel$$ Although the concentration of CO2 in the atmosphere (about 386 ppm in 2009, rising at a rate of about 1.9 ppm) is about 260 times less than the concentration of CO2 in flue gas (about 10%), the logarithmic scaling of the thermodynamic minimum energy of separation means that the minimum energy required to separate 90% of the CO2 from air (21 kJ/molCO2) is only 2.9 times greater than the minimum energy required to separate 90% of the CO2 from flue gas (7.3 kJ/molCO2). Also, it is important to note that using CO2 separated from power-plant flue gas would not create a carbon-neutral fuel because the CO2 emitted upon combustion could not be re-separated for a subsequent fuel synthesis and combustion cycle.

@richard schumacher CO2 is indeed removed from air before making liquid air products. However, the quantity is quite small and the production locations are not centralized making it difficult to utilize. In the entire U.S., approximately 10,000-20,000 tons of CO2 is removed from the air in the manufacture of all liquid air products. Typically the CO2 is captured as carbonates and is discarded because the energy required to regenerate it is prohibitive.

PARCinc: Thank you for the broad information on what you called specific learning curves. However, we should not forget that learning curves or design and manufacturing progress can be accelerated when needs grow.

We've all seen such acceleration during wartimes or the race to space and the moon etc.

The growing worldwide need for electrified vehicles will certainly support much greater battery development in the nest 10, 20 or 30 years. Progression may not be as fast as for microelectronics but it may be much faster than the last few decades. In other words it may not be linear nor gradual. Breakthroughs will come every other year or so. Many existing battery technologies will be improved and new ones will be found. Will Moore's law apply? Probably not, but some king of growing rate will be identified and could become the source of another learning curve law. Somebody will give it a name.