Process, reactor and system for preparing a bisphenol

A method for producing of bisphenol, comprising: A obscene is phenol and ketone and introducing a, the weight of the catalyst layer (14) reactor (10) system (50), wherein the phenol is the reaction to the reaction mixture, and recovering the group consisting of an from the reaction mixture. Preferably bisphenol of formula of bisphenol of phenol is the reaction is generated, or p, p ' - bisphenol. For producing bisphenol a reactor (10) comprises the arrangement of of phenol and layer (14) is ion exchange resin catalyst, and filler is the whole ion exchange resin catalyst; the heat conducting efficiency and pressure of the reducing bed.