Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectros...Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.展开更多
This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification wa...This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification was revealed combining thermogravimetric(TG)analysis,Fourier transform infrared spectroscopy,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state 13C nuclear magnetic resonance spectroscopy.Furthermore,crucible coking experiments were also conducted using industrial coal mixture and treated PET with the optimum G(PET300)or raw PET to evaluate the applicability of PET waste in coal-blending coking.According to characterization results of coke reactivity(CR),coke strength after reaction(CSR)indices,TG-related curves,pore volumes,and Raman spectra of the resultant cokes,LTPT could greatly increase the G of PET,and the optimum temperature was 300℃.Specifically,compared with the coke obtained from the blend with PET,the CR of the coke produced from the blend with PET300 decreased by 4.9%,whereas the CSR of the increased by 7.4%,suggesting that LTPT could increase the proportion of PET used for coal-blending coking.The improvement in G is attributed to the changes in C-O/C=O ratio,aliphatic H and aromaticity caused by LTPT.展开更多
基金supported by the National Natural Science Foundation of China(22308006 and 22278001)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.
基金supported by the National Natural Science Foundation of China(22308006,22278001)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘This work proposed a strategy to improve the caking index of polyethylene terephthalate(PET)waste,in which low-temperature pyrolysis treatment(LTPT)was used to depolymerize PET waste.The mechanism of G modification was revealed combining thermogravimetric(TG)analysis,Fourier transform infrared spectroscopy,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state 13C nuclear magnetic resonance spectroscopy.Furthermore,crucible coking experiments were also conducted using industrial coal mixture and treated PET with the optimum G(PET300)or raw PET to evaluate the applicability of PET waste in coal-blending coking.According to characterization results of coke reactivity(CR),coke strength after reaction(CSR)indices,TG-related curves,pore volumes,and Raman spectra of the resultant cokes,LTPT could greatly increase the G of PET,and the optimum temperature was 300℃.Specifically,compared with the coke obtained from the blend with PET,the CR of the coke produced from the blend with PET300 decreased by 4.9%,whereas the CSR of the increased by 7.4%,suggesting that LTPT could increase the proportion of PET used for coal-blending coking.The improvement in G is attributed to the changes in C-O/C=O ratio,aliphatic H and aromaticity caused by LTPT.
