Putting the practicality of constructing such a facility on Venus aside, I presume geology of Venus' crust would be a big factor here. Another important factor

Putting the practicality of constructing such a facility on Venus aside, I presume geology of Venus' crust would be a big factor here. Another important factor would be the chemistry needed to separate CO2 from Venus' atmosphere. It may or may not be different from that required for Earth's atmosphere.