That would all be outside. Polypropylene is proof against sulfuric acid. But you will need that sulfuric acid for the hydrogen it carries. Carbon from CO2 for

That would all be outside. Polypropylene is proof against sulfuric acid. But you will need that sulfuric acid for the hydrogen it carries. Carbon from CO2 for structural members, hydrocarbon for plastics and fabric for gas bags, oxygen to breathe. There is thin gaseous silicides, in case you need any silicon. It will be hard to keep the concentration of CO2 in the breathing air thin enough not to make everyone stupid, with so much of it outside.