Abstract: Technical cumylhydroperoxide of a wide composition range is cleaved in circulating reactors of a shell and tube design at the same elevated pressure as dicumyl peroxide is cleaved in a plug flow reactor with a recirculation ratio of at least 26. The cleavage process is controlled using two calorimeters and controlling the absolute .DELTA.T value which is the difference in the temperature drop between the two calorimeters.

Abstract: The invention relates to a method for purification of phenol and specifically to a method for purification of phenol produced within the process of joint phenol and acetone production by cumene method.The aim of the invention is to develop a catalyst which has high activity for phenol purification from organic mico-impurities with regeneration of the catalyst and which has high mechanical strength and stability with long catalyst life.This result is obtained by phenol purification using a heterogeneous zeolite catalyst. The acidity of the catalyst measured by butane cracking (K.sub.A) is more than 10.It is preferable to use zeolites which are designated according to the classification of the International Zeolite Association by indices FAU (zeolites X, Y), MFI (for example, ZSM-5), MOR (mordenite), MAZ (omega), BEA (beta), FER (ferrierite) and others. These zeolites can be used with binders (aluminum oxide, silica gel, aluminosilicates or aluminophosphates) and without them.