The linked paper says this uses 122 kJ/mol. I translated that into more familiar units, and it came out to 770 kWh per metric ton CO2.
If you were dumb enough to power it with coal then you'd have net emissions, but put it someplace sunny, power it with solar at 2 cents/kWh and you're paying just $15.40 in energy cost per ton of CO2 absorption. One gallon of gasoline produces 20 pounds of CO2, and there are 2204 pounds in a metric ton, so you could pay for this by adding a surcharge of just 7 cents/gallon.
Of course that's just energy cost, there's also capital cost, and I don't have an estimate for that. But it's not obviously unworkable. Reducing emissions is usually better but I could see this being pretty helpful for cleaning up things that are hard to decarbonize, and once we hit net zero we'll need tech like this already scaling to bring CO2 back down.
If you were dumb enough to power it with coal then you'd have net emissions, but put it someplace sunny, power it with solar at 2 cents/kWh and you're paying just $15.40 in energy cost per ton of CO2 absorption. One gallon of gasoline produces 20 pounds of CO2, and there are 2204 pounds in a metric ton, so you could pay for this by adding a surcharge of just 7 cents/gallon.
Of course that's just energy cost, there's also capital cost, and I don't have an estimate for that. But it's not obviously unworkable. Reducing emissions is usually better but I could see this being pretty helpful for cleaning up things that are hard to decarbonize, and once we hit net zero we'll need tech like this already scaling to bring CO2 back down.