1) Laboratory Balance: to determine weight of plant samples, 2) Clevenger apparatus: for essential oil extraction and estimation of essential oil percentage, 3) freezer to keep your extracted volatile oils , 4) Gas Chromatography-Mass Spectrometry (GC-MS): for determination of essential oil components and 5) refractometer: to determine refractive Index for essential oils. These are important apparatus that will help you.
I recommend Emad Saleh Hamed, all these apparatus are require for extraction of essential oils.but try to keep and store them in glass made containers not plastic made.