As opposed to investigating various reactor systems, the catalyst
activity and ability for regeneration during pyrolysis, received
relatively less attention in literature. In a recent study [24], two
commercial zeolites were used to study the deactivation mechanisms
during the pyrolysis of polyethylene. With the help of TG/
FT-IR analysis the authors noticed that as the catalysts were undergoing
de-activation the process gradually became similar to thermal
pyrolysis. The characteristics of the products produced with
the deactivated catalysts were the same as those obtained from
thermal runs and the catalyst lost its activity after six runs. In
another polyethylene pyrolysis catalyst deactivation study [25],
two different mechanisms were identified when deactivation and
regeneration were conducted. A reversible deactivation by coke
deposition, which can be removed by regeneration with air at
550 C, took place along with an irreversible deactivation.