If you fill your 20L still with 16,000kg you will have a big mess. Your loss will be about 15985kg. 16l in a 20l is pushing it if that’s what you meant. 75% of your flask volume is a lot. 80% is probably too much.
Figure typical losses range from 25-60% depending on starting material. Don’t guess, you’ll be wrong. Just run it like @BG305 suggested…but maybe with a few 1000ml less.
For hydrocarbon input on a 5L, we see 6-9 % of mass loss for heads, an average of 77% mains of the starting mass, and anywhere from 10-30 % of mass left as tails for first pass. Less heads, and less tails, more mains during a second pass. Distillate always comes out high 80’s low 90’s potency wise for first pass.
Is that directed at me? Those numbers are rough estimates, averages, +/- a few percent depending on variations in crude. Those averages are from multiple runs. If that was from one specific run, I can see where the concern would be.
I once had a teacher who would ask me the same question I would ask him and he would do it repeatedly untill i caught the point. I was trying to do the same and strike a light bulb moment.
The math is very subjective.
Most people should see it as this.
100% volume.
80% test.
So you should see maybe 99% of your 80 potency. So basic math can generally allow someone to subtract the upper and lower based on collective fraction removal.