SIDE-CHAIN ALKYLATION OF TOLUENE BY METHANOL OVER A BASIC ZEOLITE - A KINETIC-STUDY

A few X zeolites, exchanged with K and/or Cs, were tested as catalysts for the reaction of toluene with excess methanol (mole ratio methanol/toluene from 5 to 19) in a fixed bed reactor. Very high selectivity for the side-chain alkylation to ethylbenzene and styrene was observed. A kinetic study of the reaction at 350-degrees-C over a CsNaX catalyst was performed: the reaction rate was found to be negatively affected by a high concentration of methanol and by the addition of small amounts of ethylbenzene or styrene to the feed. Some kinetic models, able to represent such inhibition phenomena, were compared on the basis of optimization procedures.