Seems much more scientifically plausible however. I'm just a natural skeptic.
I think here they would really have to get a working prototype / pilot plant up and running, with a transparent demonstration. That's how the Haber process got support from Bosch c. 1909.
https://en.wikipedia.org/wiki/History_of_the_Haber_process
Generally speaking however, industrial processes run with pure streams of ingredients are more efficient. The rate-limiting step in the process as they describe it looks like the first one, because they're just using 400 ppm CO2 air as the input, with no pre-concentration. You'd need some kind of energy return on energy investment, i.e. how much electricity input per liter of produced fuel, plus lifetime of the catalyst etc. to make sense of how plausible it is.
https://twitter.com/ramez/status/1516199169911713794?s=21&t=...
> There are no shortcuts around the physics required to assemble a molecule.
So the process is viable, but the cost is prohibitive?
Current processes use heat+pressure, which are pretty wasteful, and often rely on burning fossil fuels in the 1st place, which will mechanically increase the financial cost”
What I understand from Prometheus is that they have a different way to “assemble molecules”, which relies on “electrocatalysts” instead of “catalysts requiring high temperature and pressure”. On the face of it, I can totally see how such a catalyst would decrease the “financial cost” without necessarily impacting the “energy cost”. It’s simply using a cheaper energy than the current processes.
The twitter answer rings similar to someone who would say “There is no shortcuts around the physics of producing light” to justify why LED lightbulbs would never make it. Most of the energy of incandescent bulbs is just heat, and there are physical process that produce light without all that heat. I don’t see any reasons why the extra heat would be needed to produce fuels
https://www.technologyreview.com/2022/04/25/1050899/promethe...
BUT... when I lived on the grid I paid $.13/kwh. At 77kwh per gallon that puts us at $10.01/gallon. It is unknown if this is just syn gas or ethanol, or what the BTU of that gallon is. And this definitely isn't diesel, which would have the biggest impact. I know when my friend did bitcoin mining he was able to get $.03kwh so... let's use that 77 * .03 = $2.31. So between $10 and $3 a gallon is actually possible.
With gas over $5 or $6 (the company is in Santa Cruz? Their gas is probably $7 or $8 at this moment, I bet) ... this will work
The other issues are... United States uses 30TW of oil a day (convert barrels of oil to BTU and convert BTU to watt hours... to convert oil used per day in watts to speak of)... and 10TW of electricity a day.
To replace 'fossil' fuels we'd need ...70TW of electricity after inefficiency conversion.
There isn't enough copper, nickle, and silver to make all those solar panels. There isn't enough public support or political capital to build nuclear reactors either. This is another flaw.
Another commentor suggested, just replacing Russian's oil at 4 million barrels a day. That's possible. And it makes it exciting.
If they used power only at production peaks and colocated with generation (saving ~10% line losses), $0.02/kWh seems in the realm of the possible.
As to lack of resources to build enough solar capacity, concentrator plants make that a non-issue.
It's important to ask these questions of what the tradeoffs really are when thinking about Energy Returned on Energy Invested, whether e-fuels would actually decrease new car production (i.e. older cars get used longer if e-fuels really make sense), the political economy ramifications if these things really worked, etc.
In prior waves of interest of things like algae-based fuels (see https://www.greentechmedia.com/articles/read/lessons-from-th... ), my rough understanding is that they could be done but the numbers just didn't work out.
Finally, it's really worth pointing out the concern of any of these things falling under solutionism when also thinking about the state of our planet from a more integrated framework such as the planetary boundaries: https://www.stockholmresilience.org/research/planetary-bound...
The price of electricity is variable, sometimes negative. You would not need to produce at levelized cost, but only when the sun is shining.