RSC sustainability最新文献

Fallen leaves represent a significant feedstock for hydrogen production due to their high cellulose content, abundance, and minimal sulfur content. These characteristics make them suitable for various hydrogen production technologies, including biohydrogen and biomass-derived liquid reforming processes, contributing to sustainable energy production. This comprehensive literature review explores fallen leaves as a low-cost biomass feedstock for hydrogen production in the pursuit of zero-carbon and sustainable energy solutions. Steam methane reforming, while cost-effective and possessing high production capacity, results in substantial carbon emissions. In contrast, electrolysis, leveraging renewable resources, is attractive but requires significant energy input. Biomass gasification and thermochemical processes show promise for sustainable hydrogen production, though further technological advancements are necessary. Additionally, anaerobic fermentation by microorganisms can directly produce hydrogen from biomass (including fallen leaves), offering an energy-efficient method that utilizes organic waste. This review evaluates hydrogen production concerning energy efficiency, economics, and environmental impact. The findings contribute to the global transition from fossil fuels to renewable energy sources, aligning with climate commitments and the goal of carbon neutrality.

In this study, several granular biocomposite carrier systems were prepared that contain biomaterials (chitosan, torrefied wheat straw and avian eggshells) as additive components at variable composition. The biocomposites were loaded with ammonium sulfate (AS) by two methods: (1) in situ addition of AS during pellet preparation, and (2) an adsorption method of AS after pellet preparation. Characterisation was carried out via spectroscopy (XRD, FT-IR) and complementary methods (TGA, acid stability). The pellet system (C1) by method (1) contained ca. 22 mg per g NH₄⁺, whereas pellet systems by method (2) contained up to ca. 40 mg per g NH₄⁺. The mol-ratio of NH₄⁺ : SO₄²⁻ varied from 2.18 (C1) to 2.72 (CW72), 2.97 (CW20), 2.64 (CW21) and 3.20 (CW22). Release studies in water showed that C1 pellets released almost 100% NH₄⁺ within 3 h, while release varied from ca. 60% (CW72), ca. 40% (C20), 20% (C21) to 10% (CW22). By comparison, the systems prepared through method (2) showed a marginal increase of the release profiles up to 96 h. Granular AS carrier systems prepared by method (2) displayed greater mechanical stability and AS content versus the systems prepared by method (1). We demonstrated the ability to tailor the physico-chemical properties of such biocomposite carriers and highlight their promising potential as slow-release fertilizer systems.

To minimize the consumption of nonrenewable resources and ensure environmental sustainability, there ought to be greater utilization of abundant and renewable greener nanobiopolymers, particularly those derived from various plants and microbes. This article discusses the various types, origins, and synthesis methods of biopolymers, including those that come from natural resources and microorganisms, with a focus on their properties in nanoformat; the most common and recently researched nanobiopolymers have been deliberated. In addition, discussion on various synthesis steps and structural characterization of green polymeric materials such as cellulose, chitin, and lignin is also incorporated. A comprehensive discussion of greener nanobiopolymers with illustrative examples has been presented for the last five years comprising their diverse types and topologies including the environmental improvements realized via the deployment of nanoencapsulation, especially the applications of polymer nanoencapsulated materials in wastewater and soil treatment. The emphasis on the use of greener nanobiopolymers for sustainable environmental remediation is specifically highlighted for the decontamination of soil, water, and air with the main objective being to offer an overview of their adaptability embracing nanotechnology. This effort could stimulate additional research in their deployment in practical environmental applications.

Benzoxazines are a promising material class due to their flexible molecular design, high thermomechanical properties, and inherent flame retardancy. Especially the latter makes them interesting for all kinds of applications, for example lightweight constructions in the transportation sector. The first commercial benzoxazines were based on bisphenol and aniline, petrochemical resources produced from crude oil. However, due to the growing demand for more sustainable materials the use of biobased resources for benzoxazine synthesis has been thoroughly investigated in the past years. In this work, we present the first commercial benzoxazines that consist of biobased compounds. After analysing the curing behaviour of these new resins using thermal analysis, polymers are manufactured and characterised from them. Finally, the resins were used for manufacturing fibre-reinforced polymers (FRP) for flame-retardant lightweight applications. Thermomechanical and combustion analysis showed that the polymers achieve high flexural moduli up to 2.8 MPa and glass transition temperatures of 100 °C and 141 °C. In addition, the biobased benzoxazines have promising flame-retardancy due to intumescence, resulting in high LOI values of 31.4 ± 0.2 and 33.3 ± 0.1%

The European Chemicals Strategy for Sustainability introduces the Safe-and-Sustainable-by-Design (SSbD) concept. It goes beyond current regulatory compliance and aims to ensure the safety and sustainability of (novel) chemicals, materials, products, and processes. It starts at early-innovation stages and follows the chemicals and materials throughout their entire lifecycle. This perspective paper presents an SSbD roadmap that explores current needs and gives recommendations for the practical operationalization of SSbD in industrial operations and processes. This roadmap was co-created including different SSbD stakeholders and encompasses three interlinked agendas on (i) research needs, (ii) skills, competencies, and education needs, and (iii) knowledge and information sharing needs. An overarching need is the development of a common understanding of SSbD with clear definitions, terminology, and criteria. In addition, SSbD operationalisation needs to be pragmatic and applied as early as possible in the innovation process. From a research needs perspective, it is essential to integrate the different fields of innovation, safety, and sustainability. From a skills, competencies and education perspective, targeted training is needed that balances the depth and breadth of SSbD required for a specific audience. These trainings should not only convey hard/technical skills, but also soft/social skills to support more sustainability-oriented decisions on all levels. From a knowledge and information sharing perspective, a strategic plan and a trusted environment are needed to support dialogue between all SSbD stakeholders while at the same time protecting intellectual property (IP). The roadmap should help to coordinate planning for the implementation of SSbD at industrial, academic, policy, and regulatory level by defining actions and raise strategic efforts.

Electrocatalytic hydrogenation (ECH) was explored as a mild technique (≤50 °C under atmospheric pressure) to produce valuable products from furfural, a promising biomass-derived platform chemical. In situ hydrogen equivalents made by water splitting were used to reduce the formyl group and saturate the heteroaromatic ring of furfural on an activated carbon cloth-supported ruthenium electrocatalyst. A systematic study was conducted to understand the relationship between the reaction conditions and the products. The factors analyzed include catholyte solution organic co-solvent content, catholyte solution acid content, and temperature. Acidity of the catholyte solution had the most significant effect on the yield of tetrahydrofurfuryl alcohol (THFA). The highest THFA yield was obtained in mildly acidic catholyte solutions (0.02 M HCl and 0.002 M HCl–0.02 M NaCl). The low carbon mole balance closure in the experiments was attributed to the side reactions of the reactants, intermediates, and products. The effects of current density on faradaic efficiency and of the functional groups attached to the furan ring on the formation of saturated heterocyclic products were also explored.

The development of sustainable products and processes involves the use of green chemistry principles. A new and facile synthesis of a recoverable copper(I) catalyst supported on magnetic crosslinked polyvinylpolypyrrolidone (Fe₃O₄-PVPP) for the synthesis of 1,2,3-triazole derivatives under copper-catalyzed azide–alkyne cycloaddition reactions (CuAAC) is presented in this study. The magnetic support was prepared by in situ co-precipitation of Fe₃O₄ in polyvinylpolypyrrolidone followed by immobilization of copper(I) on the magnetic support to afford a Cu(I)/PVPP-Fe₃O₄ composite, which was characterized using several techniques. Its catalytic efficiency in CuAAC working under low copper catalyst loading leads to the selective synthesis of 1,4-disubstituted-1,2,3-triazoles with good to excellent yields. The green aspect of this catalytic process relies on using water as catalytic reaction medium, working at room temperature, easy isolation of 1,2,3-triazoles and simple separation of the composite catalyst by exposure to an external magnet for recovery and further reuse. The greenness of the procedure was also assessed through the atom economy (AE), E-factor and EcoScale, showing low waste generation and better sustainability scores.

Lignin-based syringol monomer, 2,6-dimethoxypropylphenol (DMPP), can be upgraded through two synthetic routes to multi-functional propylpyrogallol DMPPO. With three hydroxyl groups, DMPPO can serve as a renewable polymer building block. In this study, we describe the synthesis and characterization of DMPPO epoxide mixtures based on their synthesis methodology; one route uses HBr, another a greener methodology with Nb₂O₅ catalyst in water. Epoxy thermoset polymers using the two different epoxide preparations are synthesized, characterized, and contrasted. Optimization of reaction conditions, including temperature and catalyst concentration, to enhance the performance of epoxy thermosets is discussed. Through dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), the thermo-mechanical behavior and thermal stability of the resulting epoxy thermoset networks are evaluated, shedding light on how structural differences impact performance.

The production of isobutanol from lignocellulose has gained attention due to its favorable physical and chemical properties. The use of lignocellulosic biomass as a feedstock to produce isobutanol has substantial sustainability benefits, but the biological conversion to isobutanol faces challenges, such as low yields and by-product formation. In this work, we demonstrate the high-yield production of isobutanol through microbial fermentation of pulp hydrolysates. Three hydrolysates are produced from poplar, sorghum, and switchgrass using pretreatment based on γ-valerolactone. Furthermore, we synthesize a biomass-to-isobutanol biorefinery and perform technoeconomic analysis of three resulting processes using experimental results obtained from an engineered yeast strain which consumes most of the glucose available in the hydrolysate and produces isobutanol at 89–94% theoretical yields. The corresponding minimum fuel selling price (MFSP) is $14.40–$16.01 per gasoline gallon equivalent, with the sorghum-based biorefinery resulting in the lowest price. We identify that solvent/biomass ratio during pretreatment and enzyme loading during hydrolysis have the greatest impact on the MFSP; improvements in these parameters can reduce the MFSP by 46%.