The huge generation of plastic waste has become significant environmental problem. For environmentally sustainable plastic waste management, thermochemical recycling of widely used plastic waste such as polyethylene, polypropylene, polystyrene, and polyethylene terephthalate have vigorously studied. However, development of proper recycling process for other types of plastic waste is required. In this study, a thermo-catalytic treatment was applied for recovery of value-added monomers and gaseous products from polycarbonate (PC). The systematic study investigating the relationships between pyrolysis conditions (temperature, atmospheric gas, the presence of catalyst) and yield of value-added products was performed. To make the thermochemical process environmentally benign and more efficient, carbon dioxide (CO) was used as an atmospheric gas in comparing to inert gas (N). When CO was introduced, the yield of PC monomer, bisphenol A (BPA), was nearly doubled at 600 °C. At higher temperature, BPA yield decreased with the increased yield of gaseous products. Because CO was the major gaseous product, BPA recovery from the PC pyrolysis was the useful approach in PC disposal practice. To improve BPA yield from PC pyrolysis, two MgO catalysts were utilized (medium porosity MgO-1 and ultrahigh porosity MgO-2). Catalytic pyrolysis under CO environment increased BPA yield from 12.8 (pyrolysis without catalyst under N) to 25.6 (MgO-1) and 30.5 wt% (MgO-2) at 600 °C. High porosity MgO catalyst was more effective in BPA production, and the catalyst deactivation was not shown for 4 consecutive reactions. This study informs that MgO catalyst and CO flow gas more than doubled the BPA yield from pyrolysis of PC in reference to conventional pyrolysis system (non-catalytic under N).
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.jenvman.2024.123564 | DOI Listing |
ACS Nano
January 2025
Shenzhen Key Laboratory of Smart Healthcare Engineering, Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, No. 1088 Xueyuan Road, Nanshan District, Shenzhen, Guangdong 518055, PR China.
Extracellular matrix (ECM)-based small-diameter vascular grafts (SDVGs, inner diameter (ID) < 6 mm) hold great promise for clinical applications. However, existing ECM-based SDVGs suffer from limited donor availability, complex purification, high cost, and insufficient mechanical properties. SDVGs with ECM-like structure and function, and good mechanical properties were rapidly prepared by optimizing common materials and preparation, which can improve their clinical prospects.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States.
Poly(vinyl chloride) (PVC) and polystyrene (PS) are among the least recycled plastics. In this work, we developed a simple and novel strategy to valorize PVC and PS plastics via photothermal conversion to (1-chloroethyl)benzene, a commodity chemical with excellent versatility. As PVC is known to release HCl gas and decompose into conjugated polyenes, we envisioned a dual role for PVC plastics.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
KTH Royal Institute of Technology: Kungliga Tekniska Hogskolan, Department of Fibre and Polymer Technology, SWEDEN.
The plastic waste accumulation requires facile yet effective solutions. Currently mechanical recycling typically leads to downcycling, while the environmental footprint of chemical recycling is often unacceptable. Here, we introduce a dual circularity concept, where rational molecular design paves the way for complementary closed-loop mechanical and chemical recyclability under mild conditions.
View Article and Find Full Text PDFEnviron Res
January 2025
MIIT Key Laboratory of Critical Materials Technology for New Energy Conversion and Storage, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
In recent years, the accumulation of waste plastics and emergence plastic-derived pollutants such as microplastics have driven significantly the development and updating of waste plastic utilization technology. This study prepared the porous carbon (PC-1-KOH) material directly from polyethylene terephthalate (PET) in waste plastic bottles using KOH activation and molten salt strategy for efficient removal of antibiotic tetracycline (TC). The maximum removal efficiency of TC was 100.
View Article and Find Full Text PDFAppl Radiat Isot
January 2025
Tokyo City University, 1-28-1, Tamazutsumi, Setagaya-ku, Tokyo, 158-8557, Japan.
In clearance measurements involving a single material type, a conversion factor was applied to convert measurement results to activity based on an assumed uniform density. However, this factor has been found to underestimate activity in material mixtures. In this study, we proposed a method to identify the location with the lowest detection sensitivity (minimum location) in a mixture and evaluated its applicability to the conversion factor.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!