Question Purifier filter 1.6i



I intend to install an additional handmade purifier (catch oil can) on an A3 8L, 1.6i. I say handmade because I make it from a decanter filter from a compressor.

I have a damper so that the intake is clean, so that it is no longer clogged with oil vapors that pass through the purifier and settle on the valve.

The problem is that I can't figure out what the purifier is for this model. I expected it to be somewhere up, in the intake area.

I suspect that the hose from the purifier is the one circled in photo no. 3, but where does the oil decant and what is the actual purifier filter? Also, does anyone know where the PCV valve is on this engine?

And one more question: what is that black hood, which looks like a fan, in the first picture? Does it have any ventilation role?