JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2025
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IF 6.2
Chenhao Li,Yi Niu,Linlin Yi,Yaoqiang Li,Jia Fu,Fang Tang,Kaiyuan Li,Yanyan Zou
This paper explores the application of zeolitic imidazolate framework-8 (ZIF-8) in pyrolytic disposal of poly(vinyl chloride) (PVC), with the goal of assessing the in situ catalytic removal and capture effect of ZIF-8 on Cl, elucidating the migration pattern of Cl, revealing the mechanism of in situ Cl capture by ZIF-8. The results demonstrate that excellent catalytic and Cl trapping properties are exhibited by ZIF-8, and an additional 311.1 mg/g of organic Cl from PVC is facilitated to be removed at 250 ºC. The catalytic effect enhances Cl trapping at low temperatures. The solid-solid reaction between PVC and ZIF-8 during in situ pyrolysis significantly improves Cl capture compared to ex situ pyrolysis. During in situ pyrolysis, ZIF-8 shows excellent Cl capture between 250 and 350 ºC, where Cl is primarily captured in the solid phase as inorganic Cl. ZIF-8 achieves optimal Cl capture at 300 ºC, reaching a peak HCl removal rate of 89.5 %. At this temperature, the content of solid-phase inorganic Cl reaches a maximum of 442.0 mg/g, accounting for 78.7 wt% of the total Cl content. The key to Cl capture lies in the chemical adsorption sites of Zn²⁺ and organic ligands in the ZIF-8 structure, which can react with Cl in both solid-solid and gas-solid reactions. Additionally, crystals formed during pyrolysis create an adsorption barrier, ultimately enabling efficient Cl capture.
研究领域:
环境科学
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材料科学
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化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2024
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IF 3
Zou Yanyan,Li Yaoqiang,Zhang Jiaqing,Guo Yi,Song Tonglei,Li Kaiyuan,Xu Mingjun
The incineration of a large number of old cables leads to the problem of green recycling and causes a lot of environmental problems. This paper investigates the effect of copper oxide (CuO) capture of chlorine (Cl) in the pyrolysis recycling of polyvinyl chloride (PVC)-based waste cable outer sheath, focusing on the redistribution of the contaminant Cl components under the action of oxygen (O 2 ). Analytical methods such as ion chromatography and diffraction of X-rays are employed to measure and quantify the dynamic changes of the Cl-containing three-phase products during the pyrolysis process. The results indicate that, compared to copper (Cu), the oxidized state of CuO and O 2 -rich conditions can enhance the capture of Cl. With increasing O 2 supply, 1.71–6.33 mass% of gas-phase Cl and 14.52–29.96 mass% of liquid-phase Cl convert into 16.23–36.29 mass% of solid-phase Cl. CuO reacts directly with the PVC component of the outer sheath in a solid–solid reaction, significantly reducing the generation of polluting Cl-containing aromatic compounds in the liquid-phase tar and synergistically facilitating CaCO 3 components to intimately contact with the pyrolysis gas to capture HCl. The originally stable CuCl 2 crystals are oxidized again to enter into cyclic adsorption in the form of CuO under O 2 -rich conditions. Cl is more fixed in the residue and primarily exists in the form of stable and safe CuCl 2 and CaCl 2 metallic compounds. This study has clearly elucidated the efficient in situ green solidification mechanism of Cl during the treatment of cable waste with CuO in the presence of O 2 , providing new recommendations for cable sheath formulations and solid waste management.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2021
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IF 5.541
Tian-Tian Meng,Hua Zhang,Fan Lü,Li-Ming Shao,Pin-Jing He
Polyvinyl chloride (PVC) is one of the most widely used plastics in the world. When PVC is heated, HCl will form, causing equipment corrosion, product quality decline, environmental pollution and other problems. Therefore, more attention is paid to recycling of PVC than other plastics. In this study, the reaction mechanisms of PVC with different metal oxides (MO x : CaO, ZnO, CuO, MgO, Fe 2 O 3 , Al 2 O 3 ) at low temperature (310 °C) were compared, with focus on chlorine capture and dehydrochlorination product (De-Cl PVC) property. The results showed that when the radius of metal ion was smaller, the extrapolated onset temperature ( T i ) of PVC-MO x pyrolysis tended to be lower, such as PVC-ZnO, PVC-CuO and PVC-Al 2 O 3 . Direct reaction of PVC and MO x was deduced for PVC-CuO and PVC-ZnO pyrolysis, based on the lower T i and peak temperature ( T max ) than that of PVC pyrolysis. MO x that did not significantly lower T max was supposed to react with HCl that dissociated from PVC. The addition of ZnO significantly reduced the release of HCl (0.5%) and captured 97.6% of chlorine as inorganic chloride salts. However, the chloride salts produced from PVC-MgO pyrolysis could decompose at low temperature, thus releasing HCl again, and the C atoms in PVC-CuO system could react with copper chloride salts and H 2 O, to form and release HCl. The capture effects of chlorine by Fe 2 O 3 and Al 2 O 3 were not good. With addition of MO x , all De-Cl PVCs were rich in C=C-H and (C) 3 C-H structures. Fe 2 O 3 , MgO and CuO reduced the release of volatile hydrocarbons, while CaO, ZnO and Al 2 O 3 increased the release of volatile hydrocarbons. Except for CaO and CuO, the other MO x increased the amount of residual hydrocarbon (De-Cl PVC).
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
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2024
·
IF 3
Zou Yanyan,Pau Dennis,Yi Linlin,Li Yaoqiang,Li Kaiyuan
13X zeolite–calcium oxide (CaO) composite capture agent application in the pyrolysis recovery of polyvinyl chloride (PVC)-based waste cables was investigated in this research to elucidate the agent’s efficiency in capturing chlorine (Cl) and carbon (C) during pyrolysis. The 13X zeolite–CaO mixture is subjected to separate pyrolysis of the PVC-based cable outer sheath in experimental furnaces of simulated solar-powered and thermogravimetry. Subsequently, a range of spectroscopic techniques are employed to quantitatively analyze the gaseous and solid products resulting from the pyrolysis process. Through X-ray fluorescence, total carbon, and other analyses, the research outcomes demonstrated that the capture agent exhibits superior Cl and C capture performance compared to using a single agent for plastic pyrolysis. The yield of Cl element in the solid residue has increased significantly by 130–140% under the presence of optimized composite capture agent. By determining the dynamic changes of gaseous and solid products during the cable outer sheath pyrolysis, the influence of the capture agent on the redistribution and transformation mechanisms of Cl and C elements was identified, and it was found that contaminating volatiles were well immobilized in the solid residue. This research provides a new solution for efficient Cl and C capture in the pyrolysis recovery of waste cables and determines the fixation and transformation mechanisms of Cl and C elements by the composite capture agent, indicating a potential for feasible and sustainable resource utilization of waste cables.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）