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Feedstock recycling of polycarbonate waste via thermochemical conversion supported by municipal solid waste incinerator bottom ash.

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Title: Feedstock recycling of polycarbonate waste via thermochemical conversion supported by municipal solid waste incinerator bottom ash.
Authors: Lim, Sam Yeol1 (AUTHOR), Lee, Jechan1,2 (AUTHOR) jechanlee@skku.edu
Source: Chemosphere. Nov2024, Vol. 368, pN.PAG-N.PAG. 1p.
Subjects: Municipal solid waste incinerator residues, Atmospheric carbon dioxide, Chemical recycling, Fourier transform infrared spectroscopy, Waste treatment, Plastic marine debris
Abstract: The rising demand for plastics has driven up its production, causing severe environmental challenges like CO 2 emissions and microplastic pollution. Furthermore, improper disposal of incinerator bottom ash (IBA), a byproduct of municipal solid waste (MSW) treatment, poses additional environmental risks. This study explores a method for recovering non-petroleum-based monomers from plastic products. A smartphone case waste (SCW) is used as feedstock in this study and it is made of polycarbonate (PC), confirmed by thermogravimetric analysis and Fourier transform infrared spectroscopy. The MSW incinerator bottom ash (MSW-IBA) is used as a catalyst for thermochemical conversion of SCW. To determine the optimal pyrolysis conditions for BPA recovery, experiments were conducted under different atmospheres (N₂ and CO₂) and catalyst configurations (in situ and ex situ). The MSW-IBA leads to 127% higher yield of bisphenol A (BPA), the monomer of PC, at 600 °C under a N 2 atmosphere, compared to non-catalytic conversion. In situ configuration of the catalyst loading leads to up to 147% higher BPA yield than ex situ configuration. The increased BPA production from SCW is most likely because metal oxides (e.g., CaO) present on the MSW-IBA catalyst promote the cleavage of and C–O bonds, dissociation of CO (or CO 2) and hydrogen extraction from C 1 –C 3 hydrocarbons and H 2. For the catalytic conversion of SCW under a CO 2 atmosphere, CO 2 adsorbs onto CaO in the MSW-IBA, decreasing the number of active sites. It deactivates the catalyst, resulting in a lower BPA yield (22.96 wt%) than the BPA yield obtained under the N 2 atmosphere (25.86 wt%). [Display omitted] • MSW incinerator bottom ash is used in feedstock recycling of polycarbonate waste. • MSW incineration bottom ash catalyst mainly consists of alkaline metal oxides. • Bisphenol A yield of >25.8 wt% is obtained from polycarbonate (PC) waste. • In situ catalyst loading was more effective in monomer recovery than ex situ loading. [ABSTRACT FROM AUTHOR]
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Database: Engineering Source
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Abstract:The rising demand for plastics has driven up its production, causing severe environmental challenges like CO 2 emissions and microplastic pollution. Furthermore, improper disposal of incinerator bottom ash (IBA), a byproduct of municipal solid waste (MSW) treatment, poses additional environmental risks. This study explores a method for recovering non-petroleum-based monomers from plastic products. A smartphone case waste (SCW) is used as feedstock in this study and it is made of polycarbonate (PC), confirmed by thermogravimetric analysis and Fourier transform infrared spectroscopy. The MSW incinerator bottom ash (MSW-IBA) is used as a catalyst for thermochemical conversion of SCW. To determine the optimal pyrolysis conditions for BPA recovery, experiments were conducted under different atmospheres (N₂ and CO₂) and catalyst configurations (in situ and ex situ). The MSW-IBA leads to 127% higher yield of bisphenol A (BPA), the monomer of PC, at 600 °C under a N 2 atmosphere, compared to non-catalytic conversion. In situ configuration of the catalyst loading leads to up to 147% higher BPA yield than ex situ configuration. The increased BPA production from SCW is most likely because metal oxides (e.g., CaO) present on the MSW-IBA catalyst promote the cleavage of and C–O bonds, dissociation of CO (or CO 2) and hydrogen extraction from C 1 –C 3 hydrocarbons and H 2. For the catalytic conversion of SCW under a CO 2 atmosphere, CO 2 adsorbs onto CaO in the MSW-IBA, decreasing the number of active sites. It deactivates the catalyst, resulting in a lower BPA yield (22.96 wt%) than the BPA yield obtained under the N 2 atmosphere (25.86 wt%). [Display omitted] • MSW incinerator bottom ash is used in feedstock recycling of polycarbonate waste. • MSW incineration bottom ash catalyst mainly consists of alkaline metal oxides. • Bisphenol A yield of >25.8 wt% is obtained from polycarbonate (PC) waste. • In situ catalyst loading was more effective in monomer recovery than ex situ loading. [ABSTRACT FROM AUTHOR]
ISSN:00456535
DOI:10.1016/j.chemosphere.2024.143748