It would be great to utilize existing infrastructure. I think everyone understands that. That requires H2 and Direct air capture and Sabatier process.

May work [1], I am not sure about heat recovery part, isn't heat lost in Sabatier reaction?

> Heat from sabatier reaction: 7.2 - 5.6 = 1.6 kWh

> Heat from electrolysis = 1.98 kWh

> Total heat = 3.58 kWh

> If we can recover 70% of the heat is would cover DAC heat requirement.

Climeworks is interesting company — capturing CO2 at $600/tonne, now they produce natural gas [2].

[1] https://learn.openenergymonitor.org/sustainable-energy/energ...

[2] https://www.youtube.com/watch?v=RMMj72fgz9E