Reaction kinetics and mechanism of catalyzed hydrolysis of waste PET using solid acid catalyst in supercritical CO₂

Abstract

in Wiley Online Library (wileyonlinelibrary.com)Hydrolysis of waste poly(ethylene terphthalate) (PET) using solid acid catalyst in SCCO 2 is presented in this work for the first time. The mechanism of PET chains scission was proved to be a combination of chain end and random chain scission by Fourier transform -infrared spectroscopy (FT-IR) and titration analysis. A new reaction kinetics model of PET hydrolysis in SCCO 2 was setup by introducing the Arrhenius equation into an ordinary reaction rate equation, the frequency factor and apparent activation energy were expressed in terms of temperature and CO 2 pressure, respectively. With this reaction kinetics model, the effects of temperature, and pressure were investigated. An interesting mechanism was proposed to describe the reaction process that both water molecules and hydroniums were carried and penetrated into the amorphous regions of the swollen PET by SCCO 2 , subsequently hydrolysis reaction preferentially took place in the amorphous regions of both surface and bulk of PET matrix.

The degradation potential of PET bottles in the marine environment: An ATR-FTIR based approach

“…Then, PETs with altered surface properties sink to the bottom of the sea and hydrolytic degradation starts. Esters are the key functional groups that interact with water 40 . In the old samples, the progress of the degradation becomes slower since the ester functional groups disappear.…”

1D Lignin-Based Solid Acid Catalysts for Cellulose Hydrolysis to Glucose and Nanocellulose

“…Hydrolysis at an even lower temperature of 110°C produced too little nanocellulose to be measured gravimetrically. Similar to sulfonated carbons, solid acid catalysts in biofuel synthesis, 40 or solid metal oxide superacid catalyst in poly(ethylene terphthalate) hydrolysis, 41 the HTSACF-catalyzed hydrolysis is also thought to be through the hydronium ions, whose diffusion and action is affected by both temperature and pressure associated with the hydrothermal conditions. The fact that no nanocellulose was generated at the lower temperature and pressure suggests hydronium ion diffusion and hydrolysis occur primarily on the surface chains to release glucose.…”

Chemical recycling ofPET: A stepping‐stone toward sustainability

“…Based on the FTIR and titration analysis results, it was proved that the mechanism of PET chain scission during hydrolysis involved both chain end and random scission. 92 Performing the hydrolysis reaction of PET waste with [( found to be reliable to recover monomers from PET disposal. 94 Alkali depolymerization of PET carried out using a mixture of alcoholic and ethereal solvents, where the former included methanol or ethanol, and the latter consisted of dioxane, tetrahydrofuran, or dimethoxyethane.…”

“…The catalyzed hydrolysis of PET was investigated in the presence of a solid acid catalyst in supercritical CO 2 . Based on the FTIR and titration analysis results, it was proved that the mechanism of PET chain scission during hydrolysis involved both chain end and random scission 92 …”