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Plastic waste represents one of the most urgent environmental challenges facing humankind. Upcycling has been proposed to solve the low profitability and high market sensitivity of known recycling methods. Existing upcycling methods operate under energy-intense conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. Herein, we report a tandem degradation-upcycling strategy to exploit high-value chemicals from polystyrene (PS) waste with high selectivity. We first degrade PS waste to aromatics using ultraviolet (UV) light and then valorize the intermediate to diphenylmethane. Low-cost AlCl 3 catalyzes both the reactions of degradation and upcycling at ambient temperatures under atmospheric pressure. The degraded intermediates can advantageously serve as solvents for processing the solid plastic wastes, forming a self-sustainable circuitry. The low-value-input and high-value-output approach is thus substantially more sustainable and economically viable than conventional thermal processes, which operate at high-temperature, high-pressure conditions and use precious-metal catalysts, but produce low-value oligomers, monomers, and common aromatics. The cascade strategy is resilient to impurities from plastic waste streams and is generalizable to other high-value chemicals (e.g., benzophenone, 1,2-diphenylethane, and 4-phenyl-4-oxo butyric acid). The upcycling to diphenylmethane was tested at 1-kg laboratory scale and attested by industrial-scale techno-economic analysis, demonstrating sustainability and economic viability without government subsidies or tax credits.
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Direct Upcycling of Woven Polypropylene Fabrics to Carbon‐Based Joule Heaters
Abstract While various plastic waste management practices are demonstrated to result in materials with similar properties, morphological features of plastic waste are often lost after recycling/upcycling. Particularly, synthetic textiles are a severely underutilized waste stream that contains built‐in value stemming from their woven architectures. This work demonstrates a simple upcycling strategy to convert polypropylene‐based (PP) woven fabrics to carbon fiber mats through direct pyrolysis for direct use in various end applications without need of additional processing steps, distinct from prior works converting plastic waste to carbon‐based additives. The retention of material properties and architectures, taking advantage of the inherent value with initial product manufacturing, is investigated, with optimal conditions resulting in consistent high carbon yields. Moreover, the textile‐derived carbon shows exceptional Joule heating performance, which can be employed in various heating applications, resulting in reduced energy consumption compared to conventional heating. Furthermore, decoration of fabric‐derived carbon with metal nanoparticles is demonstrated through electroplating, leading to altered surface functionality and further enhanced Joule heating performance. This work introduces a scalable method for upcycling of plastic waste to functional carbons that can completely retain initial material architectures with controlled shrinkage, providing a viable strategy for generating value‐added products toward electrification of heating processes.
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- Award ID(s):
- 2239408
- PAR ID:
- 10472578
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Sustainable Systems
- Volume:
- 8
- Issue:
- 2
- ISSN:
- 2366-7486
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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