Abstract: The present invention relates to a method for carrying out a catalysed chemical reaction using one or more liquid reactants, preferably acetone and phenol, in an upflow reactor comprising feeding at least a portion of said reactants to a bottom section of the reactor positioned below a flow distributor plate, passing said portion through the flow distributor plate, passing said portion through a layer of inert particles positioned above and preferably in contact with said flow distributor plate, passing said portion through a catalyst layer comprising a particulate catalyst, said catalyst layer being positioned above and in contact with said layer of inert particles, wherein the reactants react to form a product stream, collecting said product stream via collecting means positioned above said catalyst layer. The invention also relates to a reactor assembly.

Abstract: Methods for purifying a p,p-bisphenol A generally include distilling a feed stream comprising p,p-BPA in a distillation column at a pressure less than or equal to 20 millibars. The distillation column separates the bisphenol feed stream to produce a light fraction, an intermediate fraction and a heavy fraction. The intermediate fraction comprising the purified bisphenol contains lesser impurities that the p,p-BPA in the feed stream. In one embodiment, the intermediate stream is recovered using a side-draw. The side-draw is located between a first zone and a third zone in the distillation column.