Current Opinion in Green and Sustainable Chemistry最新文献

CO₂ capture and conversion using structured porous sorbents and catalysts is a solution to help the decarbonization of emission-intensive industries. Furthermore, porous sorbents have recently been considered for direct air capture to achieve negative CO₂ emissions. Several new prototypes and swing adsorption technologies for CO₂ capture use structured laminates and honeycomb sorbents to lower the energy penalty and improve process efficiency and kinetics. The challenges lie in tailoring and optimizing structured sorbents for their CO₂ working capacity, selectivity over other components, the effect of impurities and humidity, mass and heat transfer kinetics, and mechanical and chemical durability, which are specific to the exhaust system and flue gas composition. Recent developments in the structuring of sorbents are reviewed with a focus on the scalable approaches to improve the performance of postcombustion CO₂ capture and direct air capture processes.

Ammonia (NH₃) is widely used in the production of vital chemicals such as synthetic fertilizers and nitric acid. It has recently attracted great attention as an energy carrier due to its high hydrogen content (17 wt.% H), ease of transportation, and stability over time. However, for ammonia to fulfil this promise, a more efficient and sustainable method for its synthesis and decomposition must be developed. Significant scientific efforts have been devoted to achieving this via an in-depth understanding of the reaction mechanisms. This mini-review discusses the most relevant developments in heterogenous catalysts for ammonia synthesis and decomposition over the past two years, which has centered on structural and electronic modifications, single atom catalysis, and the use of dual/multiple catalytic sites for N₂ and H₂ activation to overcome the scaling relationship, and thereby achieve moderate reaction conditions.

Nowadays there is a strong urge to replace the fossil-based chemicals and fuels with biobased ones. In this context, the 7th principle of the green chemistry, the Sustainable Development Goals (SDGs) and the recent Safe and Sustainable by Design (SSbD) approach are the main references. Among the various biorefineries, lignocellulosic biomasses represent the most abundant resource to explore. Considering the vast plethora of useful molecules produced from lignocellulosic biomasses, levulinic acid embodies a potential starting material for the preparation of high value-added chemicals. This review explores the preparation of levulinic acid form lignocellulosic biomasses and its further valorization to high-value added compounds (γ-valerolactone, ketals and methyl/ethyl levulinate), considering the current state of the art of the available synthetic strategies, in a life cycle perspective considering the adoption of the life cycle assessment (LCA) methodology.

Aromatic monomers are key building blocks for many polymer resins for coatings applications. The rigid structure results in improved thermal and mechanical properties of the coatings, such as high hardness or scratch-resistance to name but a few. However, most of the available aromatic building blocks are very inexpensive monomers obtained from petrochemical resources. To enhance the sustainability of coatings materials, bio-based alternatives are of high interest for both industry and academia. This short review aims to highlight very recent work on biobased aromatics for coatings applications.

The landscape of chemical production has undergone a paradigm shift towards sustainability, emphasizing catalytic procedures, renewable raw materials, and green chemistry principles. Chitin, the second most abundant global biomass, offers opportunities for synthesizing nitrogen-rich aromatics, crucial for reducing the reliance on energy-intensive nitrogen sources like ammonia. This review outlines the most recent advances in methodologies for preparing nitrogen-rich furans, focusing on 3-acetamido-5-acetylfuran (3A5AF), dihydroxyethyl acetamidofuran (diHAF), 3-acetamido-5-formylfuran (3A5FF), and 3-acetamidofuran (3AF) from N-acetylglucosamine (NAG) dehydration. In addition, the review encompasses other aromatic commodities currently obtained from chitin, either by derivatization of the aforementioned furans, by deacetylation-dimerization, or other strategies. Although challenges in scaling up, product stability, and low yields persist, these furans hold promise as sustainable synthons, driving innovations in chemical synthesis.

Sewage sludges (SS) are by-products of the wastewater treatment process and are considered critical source of contaminants as they contain a diverse range of microbial, organic, and inorganic pollutants that are concerning to public health and the environment. Hydrothermal processes are particularly suitable for treating SS; however, their viability for the effective degradation and potential destruction of persistent contaminants, such as heavy metals, microbial pathogens, microplastics, per- and polyfluoroalkyl substances, pharmaceuticals, and personal care products, among others in SS is still under rapid investigations. This article reviews the source, transformation, and fate of prominent contaminants in SS during hydrothermal treatment (HT). Most contaminants in SS are to a certain extent degraded or transformed into other products under typical HT at subcritical conditions. Transformation pathways can be complex due to the diverse physicochemical and biochemical properties, including thermal stability and hydrophobicity. Critical findings were summarised with conclusions and perspectives for future works provided.

Challenges related to economic viability and production processes to sustainable aviation fuel (SAF) have significantly hindered its widespread commercial adaptations. This mini review provides the current opinion on various feedstocks and conversion processes for low-cost SAF production. The primary emphasis lies on exploring alternatives to traditional feed crops with a shift toward utilizing lignocellulosic biomass, waste feedstocks, oil-seed crops, and microalgal oil. The Fischer–Tropsch process, hydroprocessed esters and fatty acids, and nonthermal plasma method, where lignocellulosic biomass, oil-based crops, microalgal oil, and waste oils are widely used are cost effective, have high potential to produce SAF. However, technical immaturity and high cost compel detailed investigation on the optimization process using various alternative feedstock. This mini review insights the critical factors effecting reaction efficiencies, including feedstock characteristics, reaction parameters, catalyst reusability, and supports that need systematic investigation. Conclusively, this outlook delves into the challenges, solutions, and opportunities associated to cost-effective SAF production.