THE REACTION NETWORK IN THE CONVERSION OF 1,2,4-TRIMETHYLBENZENE OVERHZSM-5

A reaction network for the conversion of 1,2,4-trimethylbenzene [1,2,4 -TMB] over HZSM-5 is proposed, based on product concentrations versus space time studies at 723 K. At conversion levels below 10% the rates of formation of 1,2,3- and 1,3,5-TMB reflect the catalyst's activity f or the isomerization of 1,2,4-TMB; the isomer distributions in the xyl ene and tetramethylbenzene fraction are not thermodynamically controll ed and thus represent valuable information on the selectivity of the c atalyst. As expected, product distributions were affected by the level of conversion, and thus selectivities have to be compared at equal co nversions. (C) 1998 Academic Press.