How about adapting the Distillation Tower not just for distilling oil, but also for distilling things like liquified air and other random solutions?
Yes sure, once Distillation Tower become modular with input hatches and different output feedback hatch (undistilled), condensers and exhaust may be possible.
Now I don't understand what you mean by distilling compressed air, unless you like to get back some Nitrogen for some huge cost. I am not sure of the distillation process for air or such gases.
For now, GregTech air (compressed) is only O2 and does not include or mean any amount of Nitrogen, CO2 and rare gases.
There may be some good ideas about more gases tech, but for what I know of Forge Ore Dictionary, there is no distinction between gases and other fluids.
So lets concentrate on my initial proposition to modularize the Distillation Tower, open new enhanced perspectives with it and hope Forge to evolve with a more attuned Ore Dictionary in future versions.