About 2 MWh (thermal, or ~7GJ) per tonne of CO2 captured (not counting storing that CO2) to regenerate the chemical CO2 capturing agent. Here's a review: https://www.sciencedirect.com/science/article/pii/S095965261...
(As an aside, a gallon of gasoline emits about 10kg of CO2, so to capture that CO2 from a gallon of gasoline would require about 20kWh worth of electricity.... Typically, a gallon of gasoline gives you about as much range as 10 kWh in an electric car, so you can go 2 times as far in an electric car just using the energy it'd take to capture the CO2 from a gasoline car. And that doesn't count the electricity required to refine/crack the gasoline from crude.)
And also, on board the International Space Station, CO2 is captured from the atmosphere regeneratively. Capturing CO2 in this way takes less energy at the higher concentrations on board ISS, but is still possible.
As an aside: Much of the ISS's CO2 is converted into a hydrocarbon (methane) using hydrogen (from water and solar electricity) and, amusingly, vented to space as a waste product. The point is to recover the oxygen (again, in the form of water) from the CO2.
If we can figure out how to extract atmospheric CO2 and convert it into hydrocarbons efficiently, crude oil won’t be bart of the equation any longer — our atmospheric carbon supply will be part of a closed loop. As a lay person, that’s an awfully appealing prospect.
I wonder how many kWh it takes to pump, transport and process a gallon of gasoline when sources from crude.
But what if it's a device that already exists that moves through air with great speed, filtering through huge amounts of air? Like, say, a jet engine?
The point of this device is to take energy available on the ground and store it for use in the air, and use a storage method with a tremendous amount of energy per unit weight (hydrocarbons).