Prediction of terephthalic acid yield in aqueous hydrolysis of polyethylene terephthalate

Abstract

Aqueous hydrolysis is used to chemically recycle polyethylene terephthalate (PET) due to production of high‐quality terephthalic acid (TPA), the PET monomer. PET hydrolysis depends on various factors including PET size, catalyst concentration, and reaction temperature. So, modeling PET hydrolysis by considering the effective factors can provide useful information for material researchers to specify how to design and run these reactions. It will save time, energy, and materials by optimizing the hydrolysis conditions. Machine learning algorithms enable to design models to predict the output results. For the first time, 381 experimental data were gathered to model aqueous hydrolysis of PET. Effective factors on PET hydrolysis were connected to the TPA yield. The logistic regression was applied to rank the effective factors. Two algorithms were proposed, artificial neural network multi‐layer perceptron (ANN‐MLP) and adaptive network‐based fuzzy inference system (ANFIS). The dataset was divided into training, validating, and testing sets to train, validate, and test the models, respectively. The models predicted TPA yield sufficiently where the ANFIS model outperformed. R‐squared (R2) and Root Mean Square Error (RMSE) loss functions were employed to measure the efficiency of the models and evaluate their performance.

Subcritical CO2–H2O hydrolysis of polyethylene terephthalate as a sustainable chemical recycling platform

“…It is challenging to compare the results obtained herein with those reported in the literature for neutral hydrolysis reactions, because of the wide variety of operational conditions reported and PET substrate properties/morphologies. 13,16,56 Pereira et al have reported a TPA yield <10% when PET chips from sparking water bottles were hydrolyzed at 200 °C for 120 min. 13 It is worth mentioning that when we performed hot compressed H 2 O reactions (in the absence of N 2 ) a TPA yield <5% was observed at 200 °C for 100 min (Table S2†), which is in good agreement with the findings reported by Pereira et al who did not use N 2 to pressurize the H 2 O in those experiments.…”