Synergistic pyrolysis mechanism of polypropylene and common plastics with biomass investigated by TG-MS and in-situ FTIR

IF 5.6 2区工程技术 Q2 ENERGY & FUELS

Journal of The Energy Institute Pub Date : 2025-05-26 DOI:10.1016/j.joei.2025.102158

Yueping Liu , Suning Li , Yongcheng Yang , Yongxiang Liang , Fei Wang , Xuetong Li , Deng Zhao , Yanjun Lu , Hui Liu , Shuai Guo

{"title":"Synergistic pyrolysis mechanism of polypropylene and common plastics with biomass investigated by TG-MS and in-situ FTIR","authors":"Yueping Liu , Suning Li , Yongcheng Yang , Yongxiang Liang , Fei Wang , Xuetong Li , Deng Zhao , Yanjun Lu , Hui Liu , Shuai Guo","doi":"10.1016/j.joei.2025.102158","DOIUrl":null,"url":null,"abstract":"<div><div>The aim of this study is to investigate the role of different carbon-based structures on the pyrolysis pathway and gas product distribution of polypropylene (PP). Using in situ DRIFTS coupled with thermogravimetric mass spectrometry, this study investigated the synergistic mechanisms between polypropylene (PP) and common plastics and biomass at the molecular level. The following mechanisms were revealed: 1) Polyethylene erephthalate (PET) induces demethylation of PP through oxygenated fragments, which weakens the stability of its main chain and synergistically reduces the pyrolysis temperature. The high-temperature polyene structure of polyvinyl chloride (PVC) promotes further breakage of the PP main chain, synergistically driving the directional conversion of gas products to unsaturated hydrocarbons and chlorine-containing compounds. The phenyl groups in polystyrene (PS) trigger PP activation at low temperatures, improving the yield of toluene gas. 2) PP inhibits the decomposition of blended components through physical entanglement at low temperatures. At high temperatures, polyenes, phenyl groups and other cleavage products reorganize with PP hydroxyl fragments, promoting the enrichment of olefins, aromatics and chlorinated compounds. 3) In PP-biomass systems, it is hypothesized that the PP pyrolysis pathway is altered, enhancing the selectivity for short-chain hydrocarbons and monocyclic aromatics. This effect is likely mediated through ash-catalyzed reactions and induction by oxygen-containing fragments. This study employs in situ Fourier-transform infrared (FTIR) spectroscopy to monitor in real time the molecular-level evolution of PP-based mixed waste plastics and biomass pyrolysis, revealing fundamental carbon-chain structure-property relationships. These findings establish a mechanistic framework for the rational design of high-efficiency pyrolysis systems with precisely controlled product distributions through synergistic interactions.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"121 ","pages":"Article 102158"},"PeriodicalIF":5.6000,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Energy Institute","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1743967125001862","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENERGY & FUELS","Score":null,"Total":0}

引用次数: 0

Abstract

The aim of this study is to investigate the role of different carbon-based structures on the pyrolysis pathway and gas product distribution of polypropylene (PP). Using in situ DRIFTS coupled with thermogravimetric mass spectrometry, this study investigated the synergistic mechanisms between polypropylene (PP) and common plastics and biomass at the molecular level. The following mechanisms were revealed: 1) Polyethylene erephthalate (PET) induces demethylation of PP through oxygenated fragments, which weakens the stability of its main chain and synergistically reduces the pyrolysis temperature. The high-temperature polyene structure of polyvinyl chloride (PVC) promotes further breakage of the PP main chain, synergistically driving the directional conversion of gas products to unsaturated hydrocarbons and chlorine-containing compounds. The phenyl groups in polystyrene (PS) trigger PP activation at low temperatures, improving the yield of toluene gas. 2) PP inhibits the decomposition of blended components through physical entanglement at low temperatures. At high temperatures, polyenes, phenyl groups and other cleavage products reorganize with PP hydroxyl fragments, promoting the enrichment of olefins, aromatics and chlorinated compounds. 3) In PP-biomass systems, it is hypothesized that the PP pyrolysis pathway is altered, enhancing the selectivity for short-chain hydrocarbons and monocyclic aromatics. This effect is likely mediated through ash-catalyzed reactions and induction by oxygen-containing fragments. This study employs in situ Fourier-transform infrared (FTIR) spectroscopy to monitor in real time the molecular-level evolution of PP-based mixed waste plastics and biomass pyrolysis, revealing fundamental carbon-chain structure-property relationships. These findings establish a mechanistic framework for the rational design of high-efficiency pyrolysis systems with precisely controlled product distributions through synergistic interactions.

查看原文本刊更多论文

利用TG-MS和原位FTIR研究了聚丙烯和普通塑料与生物质的协同热解机理

本研究旨在探讨不同碳基结构对聚丙烯（PP）热解途径及气体产物分布的影响。本研究利用原位漂移与热重质谱联用技术，在分子水平上研究了聚丙烯（PP）和普通塑料与生物质之间的协同作用机制。结果表明：1)聚对苯二甲酸乙二醇酯（PET）通过氧合片段诱导PP脱甲基化，使其主链稳定性减弱，协同降低热解温度；聚氯乙烯（PVC）的高温多烯结构促进PP主链进一步断裂，协同推动气体产物向不饱和烃和含氯化合物的定向转化。聚苯乙烯（PS）中的苯基在低温下触发PP活化，提高甲苯气体的产率。2) PP在低温下通过物理缠结抑制共混组分的分解。在高温下，多烯、苯基等解理产物与PP羟基片段重组，促进烯烃、芳烃和氯化化合物的富集。3)在PP-生物质体系中，假设改变了PP的热解途径，提高了对短链烃和单环芳烃的选择性。这种效应可能是通过灰催化反应和含氧碎片诱导介导的。本研究采用原位傅里叶变换红外（FTIR）光谱技术实时监测pp基混合废塑料的分子水平演变和生物质热解过程，揭示了基本的碳链结构-性能关系。这些发现为合理设计高效热解体系建立了机制框架，并通过协同作用精确控制产物分布。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Journal of The Energy Institute 工程技术-能源与燃料

CiteScore

10.60

自引率

5.30%

发文量

166

审稿时长

16 days

期刊介绍： The Journal of the Energy Institute provides peer reviewed coverage of original high quality research on energy, engineering and technology.The coverage is broad and the main areas of interest include: Combustion engineering and associated technologies; process heating; power generation; engines and propulsion; emissions and environmental pollution control; clean coal technologies; carbon abatement technologies Emissions and environmental pollution control; safety and hazards; Clean coal technologies; carbon abatement technologies, including carbon capture and storage, CCS; Petroleum engineering and fuel quality, including storage and transport Alternative energy sources; biomass utilisation and biomass conversion technologies; energy from waste, incineration and recycling Energy conversion, energy recovery and energy efficiency; space heating, fuel cells, heat pumps and cooling systems Energy storage The journal''s coverage reflects changes in energy technology that result from the transition to more efficient energy production and end use together with reduced carbon emission.