I have the feeling that unless you are talking substantial research, prototyping and development time you are barking up the wrong tree. To build a centrifuge to separate some form of veggie oil from water you would start with the specific gravity of the two substances, rpm of the bowl, angle of bowl sides and on and on. I'm not you but if I were I'd be looking for a different solution.
I don't know the relative vapor pressure of your substances but a heated vacuum chamber will refine substances fairly rapidly.
Or possibly some sort of coalescer system. For an automated, sort of coalescer system, have a look at
which is stated to work with bio-diesel.
There is also electrostatic precipitation with gravity separation.