Thermal depolymerization of polyethylene terephthalate waste and its use in coal-blending coking  

聚对苯二甲酸乙二醇酯废塑料的热解聚及其在配煤炼焦中的应用

作　　者：FANG Shixian SONG Huan LIU Xiangchun CUI Ping 方世仙;宋欢;刘祥春;崔平(安徽工业大学化学与化工学院安徽省煤清洁转化与低碳利用重点实验室,安徽马鞍山243032)

机构地区：[1]Anhui Province Key Laboratory of Coal Clean Conversion&Low-carbon Utilization,School of Chemistry and Chemical Engineering,Anhui University of Technology,Ma’anshan 243002,China

出　　处：《燃料化学学报(中英文)》2025年第4期602-612,共11页Journal of Fuel Chemistry and Technology

基　　金：supported by the National Natural Science Foundation of China(22308006,22278001);the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).

摘　　要：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.利用低温热解预处理(LTPT)解聚聚对苯二甲酸乙二醇酯(PET)废塑料,以提高其黏结性(G)。利用热重(TG)、傅里叶变换红外光谱、热解-气相色谱-质谱连用技术和13C固体核磁揭示LTPT改性PET黏结性机理。此外,以工业混煤和G改性最优PET(PET300)或原PET为原料,进行坩埚焦实验。对所制备的焦炭进行CO_(2)反应性(CR)、反应后强度(CSR)、TG、孔体积和拉曼谱图测试。结果表明,LTPT可以显著提高PET的G值,最优改性温度为300℃。G值的变化归因于LTPT引起的PET的C-O/C=O、脂肪族H和芳香性变化的共同作用所致。此外,与含PET的混煤制备的焦炭相比,含PET300的混煤制备焦炭的CR降低了4.9%,CSR增加了7.4%,表明,LTPT可以提高PET用于配煤炼焦的配入量。

关 键 词：polyethylene terephthalate PYROLYSIS caking index coking property 

分 类 号：TQ522.1[化学工程—煤化学工程]