Just to check am I doing right. When I’m destiling meth from BD (90kg batch) usual I get around 3,5 kg of meth. Distilling process takes around 4 hrs. I’m raising BD temperature to 65deg C and introducing air with compressor to the bottom of processor (appleseed type). Without compressor I can’t get all meth out in 4hrs because my condenser inlet is small (10mm pipe). As a condenser I have a copper pipe (6mm and 1,5mm long) wounded into spiral and cooled with cold water.
Questions:

Is 3.5kg too much meth from BD? In process I’m using KOH 8g/l and 20% methalnol, 2 hrs processing time.
Is 4hrs too long time to distill whole meth out?
Is it good to work with compressor on order to get methanol out of BD?

Thanks!