[malfist]

Even if it winds up back in the atmosphere, it's displaced an equivalent amount of new CO2 going into the atmosphere.

Pulling enough CO2 to make a kilogram of propane and then burning that kilogram of propane for electricity is still better than burning a kilogram of freshly fracked propane.

One offsets consumption. One just adds consumption.

[bluGill]

Only if your source of electric doesn't add CO2. If you burn coal to make propane you are worse off CO2 wise than using regular propane. We have a lot of wind and solar, but most places they are still a minor part of the electric mix (if this applies to you, it wouldn't be hard to get a lot more wind/solar in your grid).