Estudio cinético de la cristalización de zeolita ZSM-5 a partir de Perlita Expandida empleando el modelo de Avrami?

DESTEFANIS, HUGO; CORREGIDOR PABLO; ACOSTA DELICIA

Montevideo

Congreso; XXV Congreso Iberoamericano de Catálisis; 2016

CICAT 2016

The crystallization kinetics of ZSM-5 zeolite has been studied at 170, 180 and 190 °C following the Kolmorogov-Johnson-Mehl-Avrami model. From the crystallization curves, stages as nucleation (induction + transition) and crystalline grow have been differentiated by measuring kinetics parameters such as period length, rate constant, Avrami?s law exponent and activation energies. From the results, a n=3,5 kinetics has been found, suggesting a stage between instantaneous and a sporadic nucleation, and a three-dimensional crystalline grow. Nucleation stage represents the highest activated process and denotes the rate-determining step. When nuclei reach the appropriate size; they grow consuming less energy until crystals are generated. As was expected, crystallization process of ZSM-5 from Perlite represents a more energetic process than the one using TPA+, in both nucleation substeps.