To the guy above, i am also an undergrad applicant but all i know is bath has the best reputatiom out of those three. Imperial is probably the best in this country at chemical engineering alongside Oxbridge. Bath and Imperial will most likely have the best international rep. Imperial academically is awesome, its on par with oxbridge (it would have been my firm uni if i got the predicted grades), the place looks great and its also in london so you know what comes with that. Since chem eng is a well respectes degree and job prospects are great, i doesn't really matter much as to where you go but the gap between imperial and those three aren't that big tbh.