Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology
Polyethylene terephthalate (PET) waste was depolymerized into bis(2-hydroxyethyl) terephthalate (BHET) through glycolysis with the aid of oyster shell-derived catalysts. The equilibrium yield of BHET was as high as 68.6% under the reaction conditions of mass ratios (EG to PET = 5, catalyst to PET =...
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MDPI AG
2022-02-01
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| Series: | Polymers |
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| Online Access: | https://www.mdpi.com/2073-4360/14/4/656 |
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| author | Yonghwan Kim Minjun Kim Jeongwook Hwang Eunmi Im Geon Dae Moon |
| author_facet | Yonghwan Kim Minjun Kim Jeongwook Hwang Eunmi Im Geon Dae Moon |
| author_sort | Yonghwan Kim |
| collection | DOAJ |
| description | Polyethylene terephthalate (PET) waste was depolymerized into bis(2-hydroxyethyl) terephthalate (BHET) through glycolysis with the aid of oyster shell-derived catalysts. The equilibrium yield of BHET was as high as 68.6% under the reaction conditions of mass ratios (EG to PET = 5, catalyst to PET = 0.01) at 195 °C for 1 h. Although biomass-derived Ca-based catalysts were used for PET glycolysis to obtain BHET monomers, no statistical analysis was performed to optimize the reaction conditions. Thus, in this study, we applied response surface methodology (RSM) based on three-factor Box–Behnken design (BBD) to investigate the optimal conditions for glycolysis by analyzing the independent and interactive effects of the factors, respectively. Three independent factors of interest include reaction time, temperature, and mass ratio of catalyst to PET under a fixed amount of ethylene glycol (mass ratio of EG to PET = 5) due to the saturation of the yield above the mass ratio. The quadratic regression equation was calculated for predicting the yield of BHET, which was in good agreement with the experimental data (R<sup>2</sup> = 0.989). The contour and response surface plots showed the interaction effect between three variables and the BHET yield with the maximum average yield of monomer (64.98%) under reaction conditions of 1 wt% of mass ratio (catalyst to PET), 195 °C, and 45 min. Both the experimental results and the analyses of the response surfaces revealed that the interaction effects of reaction temperature vs. time and temperature vs. mass ratio of the catalyst to the PET were more prominent in comparison to reaction time vs. mass ratio of the catalyst to the PET. |
| first_indexed | 2024-03-09T21:11:56Z |
| format | Article |
| id | doaj.art-4b33caea910540f9ac80cf8053e1d6ec |
| institution | Directory Open Access Journal |
| issn | 2073-4360 |
| language | English |
| last_indexed | 2024-03-09T21:11:56Z |
| publishDate | 2022-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Polymers |
| spelling | doaj.art-4b33caea910540f9ac80cf8053e1d6ec2023-11-23T21:43:41ZengMDPI AGPolymers2073-43602022-02-0114465610.3390/polym14040656Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface MethodologyYonghwan Kim0Minjun Kim1Jeongwook Hwang2Eunmi Im3Geon Dae Moon4Department of Advanced Materials R&D Center, Dae-Il Corporation (DIC), Ulsan 44914, KoreaRIKEN Center for Emergent Matter Science (CEMS), Saitama 351-0198, JapanDepartment of Advanced Materials R&D Center, Dae-Il Corporation (DIC), Ulsan 44914, KoreaDongnam Division, Korea Institute of Industrial Technology (KITECH), Busan 46938, KoreaDongnam Division, Korea Institute of Industrial Technology (KITECH), Busan 46938, KoreaPolyethylene terephthalate (PET) waste was depolymerized into bis(2-hydroxyethyl) terephthalate (BHET) through glycolysis with the aid of oyster shell-derived catalysts. The equilibrium yield of BHET was as high as 68.6% under the reaction conditions of mass ratios (EG to PET = 5, catalyst to PET = 0.01) at 195 °C for 1 h. Although biomass-derived Ca-based catalysts were used for PET glycolysis to obtain BHET monomers, no statistical analysis was performed to optimize the reaction conditions. Thus, in this study, we applied response surface methodology (RSM) based on three-factor Box–Behnken design (BBD) to investigate the optimal conditions for glycolysis by analyzing the independent and interactive effects of the factors, respectively. Three independent factors of interest include reaction time, temperature, and mass ratio of catalyst to PET under a fixed amount of ethylene glycol (mass ratio of EG to PET = 5) due to the saturation of the yield above the mass ratio. The quadratic regression equation was calculated for predicting the yield of BHET, which was in good agreement with the experimental data (R<sup>2</sup> = 0.989). The contour and response surface plots showed the interaction effect between three variables and the BHET yield with the maximum average yield of monomer (64.98%) under reaction conditions of 1 wt% of mass ratio (catalyst to PET), 195 °C, and 45 min. Both the experimental results and the analyses of the response surfaces revealed that the interaction effects of reaction temperature vs. time and temperature vs. mass ratio of the catalyst to the PET were more prominent in comparison to reaction time vs. mass ratio of the catalyst to the PET.https://www.mdpi.com/2073-4360/14/4/656PETdepolymerizationcatalystoyster shellglycolysisresponse surface methodology |
| spellingShingle | Yonghwan Kim Minjun Kim Jeongwook Hwang Eunmi Im Geon Dae Moon Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology Polymers PET depolymerization catalyst oyster shell glycolysis response surface methodology |
| title | Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology |
| title_full | Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology |
| title_fullStr | Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology |
| title_full_unstemmed | Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology |
| title_short | Optimizing PET Glycolysis with an Oyster Shell-Derived Catalyst Using Response Surface Methodology |
| title_sort | optimizing pet glycolysis with an oyster shell derived catalyst using response surface methodology |
| topic | PET depolymerization catalyst oyster shell glycolysis response surface methodology |
| url | https://www.mdpi.com/2073-4360/14/4/656 |
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