Yes, sometimes this is practicable. But many locations do not have sufficient renewable energy available, and nuclear has become unpalatable for a variety of reasons.
Scrubbing CO2 from boiler or turbine exhaust takes a small fraction (5%-ish) of the energy needed to convert it into fuel. If the source is a power plant, the CO2 can be captured at a cost of efficiency penalty of around 10%.
Once it is captured, storing and transporting CO2 to a location with abundant clean energy is also relatively simple.
Scrubbing CO2 from boiler or turbine exhaust takes a small fraction (5%-ish) of the energy needed to convert it into fuel. If the source is a power plant, the CO2 can be captured at a cost of efficiency penalty of around 10%.
Once it is captured, storing and transporting CO2 to a location with abundant clean energy is also relatively simple.