CONVERSION OF METHYLCYCLOPENTANE ON RARE-EARTH EXCHANGED Y-ZEOLITE FCC CATALYSTS

Methylcyclopentane was reacted under low conversion conditions on vari ous plant equilibrated and laboratory steam dealuminated commercial, r are earth exchanged, Y zeolite FCC catalysts at reaction temperatures of 450 to 510 degrees C. Reaction products included mainly C-5- compou nds as well as methylcyclopentene, saturated open chain C-6 isomers, C -6 alkenes, C-5 to C-8 cyclic, and aromatic compounds. The reaction is sensitive to catalyst properties, as well as a good probe to evaluate various reactions typical of FCC, like cracking, isomerization and hy drogen transfer, both total catalyst acidity and zeolite unit cell siz e being necessary to ascertain catalyst performance. The same trends w ere observed on all the samples. The extension of the reactions follow ing single active site mechanisms (cracking and isomerization) correla ted with total catalyst acidity. Reactions obeying mechanisms that dem and paired active sites (hydrogen transfer) can be accounted for more properly on a zeolite unit cell size basis. Hydrogen transfer decrease s significantly at unit cell sizes lower than 24.30 Angstrom. Lower te mperatures favored both isomerization and hydrogen transfer against cr acking. The reaction could be used as a test to provide complementary information for commercial catalyst evaluation procedures.