[yazaddaruvala]

I'm not Gustaf, but I'll try to answer this.

The return on investment for a lot of Carbon capture/sequestering is not lucrative (or at least the business models are not yet apparent). The long term VC angle for air to fuel seems straight forward.

- Mars alone will be a huge market for such technology. Driving a lot of demand 100-200 years out (if not a big market in 20-40 years).

- Shanghai, et-al, need air filters. Now imagine a filter which also generates a sellable resource; fuel. I imagine that machine would sell quite well in those markets.

- With the right level of efficiency, a new era of "sail" boats could be powered by reclaimed fuel from air. Imagine the market for a cargo/cruise ship leaving port with an empty fuel tank, and days later reaching the destination port with a full tank and its goods delivered.

- With the right level of efficiency, this only improves the efficiency of coal plants. Burning coal for electricity but also reclaiming the CO2 for fuel.

[Xixi]

I don't see how you could make a "sail" boat powered by reclaimed fuel from air, as there is no fuel in the air. You will need a source of energy to convert the CO2 to fuel. In nature the most common (to my knowledge) CO2 -> fuel process is called photosynthesis, and is powered by the sun.

CO2 -> fuel consumes energy (that is stored in the fuel). Fuel -> CO2 releases it.

[yazaddaruvala]

Sorry, in the case of "sail" boats, I worded it poorly before. Wind turbine-like "sails" could act as a propulsion source when the wind direction is correct, and generate energy and funnel the air into the CO2 -> fuel machine when the direction of wind is non-optimal for propulsion.

I agree in all of the cases I mentioned there would always need to be some energy source.