Enhanced decolorization behaviors of colored PET textiles by supercritical carbon dioxide as part of the recycling process

IF 3.4 3区工程技术 Q2 CHEMISTRY, PHYSICAL

Journal of Supercritical Fluids Pub Date : 2025-03-27 DOI:10.1016/j.supflu.2025.106607

Teng Huang, Xin Wei, Shaoqing Qu, Weizhong Zheng, Ling Zhao

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引用次数: 0

Abstract

Currently, most colored Polyethylene terephthalate (PET) textiles are not recycled, because the presence of dyes leads to uncontrollable coloration in chemically recycled PET products. Traditional solvent-based decolorization faces scalability challenges due to high solvent use, low efficiency, and environmental impact. This study explores scCO₂ to enhance solvent decolorization by reducing PET-dye interactions. An scCO₂-assisted decolorization process was established in a batch reactor. Optimal conditions were identified at 8 MPa, 90 °C, and solid-to-liquid ratio of 1:20, enabling 86 % disperse dye removal within 20 min. Under higher energy consumption conditions (1 h, 120 °C), the single-cycle decolorization efficiency reached 97 %. Considering the liquid phase renewal in a continuous process, repeated decolorization of the treated PET enabled complete dye removal within three cycles. The kinetics were studied with activation energy calculated. Additionally, the process did not change the structure of stripping solvents and disperse dyes, allowing for subsequent recycling and reuse.

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来源期刊

Journal of Supercritical Fluids 工程技术-工程：化工

CiteScore

7.60

自引率

10.30%

发文量

236

审稿时长

56 days

期刊介绍： The Journal of Supercritical Fluids is an international journal devoted to the fundamental and applied aspects of supercritical fluids and processes. Its aim is to provide a focused platform for academic and industrial researchers to report their findings and to have ready access to the advances in this rapidly growing field. Its coverage is multidisciplinary and includes both basic and applied topics. Thermodynamics and phase equilibria, reaction kinetics and rate processes, thermal and transport properties, and all topics related to processing such as separations (extraction, fractionation, purification, chromatography) nucleation and impregnation are within the scope. Accounts of specific engineering applications such as those encountered in food, fuel, natural products, minerals, pharmaceuticals and polymer industries are included. Topics related to high pressure equipment design, analytical techniques, sensors, and process control methodologies are also within the scope of the journal.