| Title |
Development of Eco-Friendly and Sustainable PET Glycolysis Using Sodium Alkoxides as Catalysts |
| ID_Doc |
13704 |
| Authors |
Javed, S; Vogt, D |
| Title |
Development of Eco-Friendly and Sustainable PET Glycolysis Using Sodium Alkoxides as Catalysts |
| Year |
2023 |
| Published |
Acs Sustainable Chemistry & Engineering, 11, 31 |
| DOI |
10.1021/acssuschemeng.3c01872 |
| Abstract |
The massive accumulation of postconsumer polyethyleneterephthalate(PET) waste in the environment demands enhancement in the recyclingrate to tackle global pollution. At the same time, efficient recyclingwill contribute to a future circular economy. PET glycolysis has emergedas a promising chemical recycling method that turns PET into a widelyused monomer, bis(2-hydroxyethyl)terephthalate (BHET), and adds valueto waste. For reasons of comparability, all reported studies on PETglycolysis so far used the same work-up procedure to separate residualPET from the BHET product: Addition of hot water to the reaction mixture,filtration to remove residual PET, and crystallization of BHET fromthe filtrate by cooling. Water not only destroys the catalyst butalso has to be removed to reuse ethylene glycol. We herein reporta new "green" glycolysis approach without the need foran anti-solvent using simple sodium alkoxides (MeONa and EtONa) ascatalysts. A response surface methodology (RSM) based on the Box-Behnkendesign was applied to optimize the reaction parameters. Under optimumconditions, the results demonstrated the validity of the optimization.EG was successfully recycled and PET conversion was found close tothe initial recycling run. The optimum recipe was applied to analyzethe tolerance of the catalysts, MeONa and EtONa, in depolymerizingcolored PET waste and mixed PET waste. The findings indicate thatboth catalysts can effectively break down both types of waste undereco-friendly glycolysis conditions, with MeONa resulting in higherPET conversion. This demonstrates that BHET precipitation is achievablewithout the use of water, reusing the EG and maintaining catalystactivity for mixed PET waste. These outcomes offer a promising basisfor further developing a new and more efficient PET recycling technology. Efficient PET recycling with green glycolysisusing sodiumalkoxides, enabling BHET precipitation without water, reusing ethyleneglycol, and tolerating mixed waste. |
| Author Keywords |
chemical recycling; PET depolymerization; greenglycolysis; response surface methodology; alkoxidecatalysts |
| Index Keywords |
Index Keywords |
| Document Type |
Other |
| Open Access |
Open Access |
| Source |
Science Citation Index Expanded (SCI-EXPANDED) |
| EID |
WOS:001033227300001 |
| WoS Category |
Chemistry, Multidisciplinary; Green & Sustainable Science & Technology; Engineering, Chemical |
| Research Area |
Chemistry; Science & Technology - Other Topics; Engineering |
| PDF |
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