Help!I will get graduated in November in chemical engineering an I'd like to start a PhD in that period.Is it possible?Do I have to apply before gettinr graduated?

you can apply before you graduate, if graduation to you means the graduation ceremony. if you'll be done with your exams by the start date which will be in sept. then apply. by the way, in the UK, PhD students can start in sept, jan or april.

Apply for projects starting in October and see if they'll defer your start date until November/December