In a sealed reactor but vented to atmosphere (GL) once the head space becomes saturated with methanol it can't absorb any more so evaporation stops, The most I've had come out of the condenser, due to gas expansion, is about an eggcup full.
Interesting. That's almost the exact opposite of my experience. Almost all my meth comes out of the condenser while heating to 90, I run compressed air injection to remove the last of it.
Is that with or without the pump running?
With the pump and 3 x 2 stage eductors running.
Tony has injected and run a batch at very high temp as well and got the same results, next to no loss of methanol.