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Synthetic fibres cover most of the textile market, but their value chain is almost entirely linear. Common raw materials are non-renewable and oil-derived while requiring large amounts of (toxic) chemicals and energy for their processing into final products. In addition, synthetic textiles are usually non-biodegradable polymers; therefore, sustainable approaches for their depolymerisation into reusable monomers have not been implemented yet. As a result, most post-consumer synthetic textile waste ends up being landfilled, dispersed in the environment or incinerated, thus contributing significantly to global pollution. A possible solution to this issue is the design and use of advanced catalysts for their chemical recycling. This manuscript reviews the most significant approaches that appeared in the literature in the time span of 2015–2024, covering the selective depolymerisation process of synthetic waste textile to added-value reusable monomers using chemical catalysts. Unselective processes, for example, to produce fuel mixtures, biocatalytic methods and depolymerisation of polyolefins are not covered. The general aspects of the catalytic depolymerisation of synthetic polymers are briefly discussed, and the catalytic chemical recycling of synthetic textiles is detailed by the polymer type. While contributing to the overall achievement of the sustainable development goals, chemical recycling of synthetic textile waste may represent a useful strategy toward the circularity of the textile sector, which is almost unexplored. [ABSTRACT FROM AUTHOR]

Lignin represents the largest aromatic carbon resource in plants, holding significant promise as a renewable feedstock for bioaromatics and other cyclic hydrocarbons in the context of the circular bioeconomy. However, the methoxy groups of aryl methyl ethers, abundantly found in technical lignins and lignin‐derived chemicals, limit their pertinent chemical reactivity and broader applicability. Unlocking the phenolic hydroxyl functionality through O‐demethylation (ODM) has emerged as a valuable approach to mitigate this need and enables further applications. In this review, we provide a comprehensive summary of the progress in the valorization of technical lignin and lignin‐derived chemicals via ODM, both catalytic and non‐catalytic reactions. Furthermore, a detailed analysis of the properties and potential applications of the O‐demethylated products is presented, accompanied by a systematic overview of available ODM reactions. This review primarily focuses on enhancing the phenolic hydroxyl content in lignin‐derived species through ODM, showcasing its potential in the catalytic funneling of lignin and value‐added applications. A comprehensive synopsis and future outlook are included in the concluding section of this review. [ABSTRACT FROM AUTHOR]

Basic carbocatalyst made of simple natural precursors using environmentally friendly processes are eagerly required for a wide range of chemical processes. This work is devoted to a carbocatalyst with base functionality from soybean flour as a nitrogen‐rich carbon source. This metal‐free basic carbocatalyst showed a density of basic sites of 0.165 mmol g−1 as quantified via CO2‐TPD. The activity of the prepared basic carbons was successfully confirmed in two industrially important base‐catalyzed reactions of green chemistry, namely, ring‐opening polymerization (ROP) of ϵ‐caprolactone and transesterification of isosorbide with dimethyl carbonate. Utilizing the prepared basic carbon in the ROP reaction of ϵ‐caprolactone, gave a white polymer with high molecular weight (Mw=30000 g mol−1), which is comparable to industrial products. Moreover, a yield of 79 % of isosorbide bismethyl carbonate was obtained using the prepared basic carbon in isosorbide transesterification with dimethyl carbonate at 493 K for 6 hours. [ABSTRACT FROM AUTHOR]

Sodium lignosulfonate (LS) was valorized to low molecular weight (Mw) fractions by combining solvothermal (SF) and catalytic hydrogenolysis/hydrogenation fragmentation (SHF) in a continuous flow system. This was achieved in either alcohol/H2O (EtOH/H2O or MeOH/H2O) or H2O as a solvent and Ni on nitrogen-doped carbon as a catalyst. The tunability according to the temperature of both SF and catalytic SHF of LS has been separately investigated at 150 °C, 200 °C, and 250 °C. In SF, the minimal Mw was 2994 g mol−1 at 250 °C with a dispersity (Đ) of 5.3 using MeOH/H2O. In catalytic SHF using MeOH/H2O, extremely low Mw was found (433 mg gLS−1) with a Đ of 1.2 combined with 34 mg gLS−1. The monomer yield was improved to 42 mg gLS−1 using dual catalytic beds. These results provide direct evidence that lignin is an unstable polymer at elevated temperatures and could be efficiently deconstructed under hydrothermal conditions with and without a catalyst. [ABSTRACT FROM AUTHOR]

This article, titled "Inside Back Cover: Advancements and Perspectives toward Lignin Valorization via O-Demethylation," discusses the process of lignin O-demethylation and its potential applications. The authors, Bert U. W. Maes and Bert F. Sels, provide a comprehensive summary of the advancements and perspectives in this field. Lignin, a component of plant cell walls, contains methoxy groups that limit its reactivity and usefulness. Through O-demethylation, lignin can be transformed into a product rich in phenolic functionality, which has broader applications. The article is authored by Xian Wu, Ewoud Smet, Francesco Brandi, Deepak Raikwar, Zhenlei Zhang, Bert U. W. Maes, and Bert F. Sels. [Extracted from the article]

This article, titled "Advancements and Perspectives toward Lignin Valorization via O-Demethylation," discusses the process of O-demethylation in lignin, which is a type of plant material. The authors, Bert U. W. Maes and Bert F. Sels, provide a comprehensive review of the advancements and potential applications of O-demethylation in lignin. They explain that the presence of methoxy groups in lignin limits its reactivity and usefulness, but through O-demethylation, lignin can be transformed into a product rich in phenolic functionality, which has broader applications. The article is authored by Xian Wu, Ewoud Smet, Francesco Brandi, Deepak Raikwar, Zhenlei Zhang, Bert U. W. Maes, and Bert F. Sels. [Extracted from the article]

Lignin represents the largest aromatic carbon resource in plants, holding significant promise as a renewable feedstock for bioaromatics and other cyclic hydrocarbons in the context of the circular bioeconomy. However, the methoxy groups of aryl methyl ethers, abundantly found in technical lignins and lignin-derived chemicals, limit their pertinent chemical reactivity and broader applicability. Unlocking the phenolic hydroxyl functionality through O-demethylation (ODM) has emerged as a valuable approach to mitigate this need and enables further applications. In this review, we provide a comprehensive summary of the progress in the valorization of technical lignin and lignin-derived chemicals via ODM, both catalytic and non-catalytic reactions. Furthermore, a detailed analysis of the properties and potential applications of the O-demethylated products is presented, accompanied by a systematic overview of available ODM reactions. This review primarily focuses on enhancing the phenolic hydroxyl content in lignin-derived species through ODM, showcasing its potential in the catalytic funneling of lignin and value-added applications. A comprehensive synopsis and future outlook are included in the concluding section of this review., (© 2023 Wiley-VCH GmbH.)