3D Lamellar Structure of Biomass-Based Porous Carbon Derived from Towel Gourd toward Phase Change Composites with Thermal Management and Protection

The hidden concept and the beauty of multiple "R" in the framework of waste strategies development reflecting to circular economy principles

There are numerous unresolved research questions, along with ongoing debates, regarding how to achieve a circular economy and at what level. The forthcoming circular economy standard (ISO 59000 framework, ISO59010) as a result from the ISO/TC 323, from the International Organization for Standardization (ISO) aims to offer global implementation pathways using a unified technical language. The most challenging aspect of circularity, whether viewed scientifically, technically, and/or legislatively, is how to enhance prosperity while reducing reliance on primary materials and energy to achieve climate neutrality by 2050, thereby aiding the EU in achieving a successful and equitable transition towards a sustainable future. Strategies in the framework of waste management and circular economy are essential and needed to reduce the impact of several processes on the environment through product, processes, and corporate policies using green applicable sustainable resources and environmental management systems. In addition, "measuring something that is not there" is very complex and not fully comprehensible, not clear and not tangible from organizations, researchers, policy makers and citizens. The willingness and ability of individuals or organizations to take actions towards a low-carbon society involves grappling with various perspectives, such as social norms and economic viability. Circular economy is considered a tool in combating climate change and implementing climate mitigation (as well as adaptation) measures. Moreover, to date, there has been no common scientific or technical language for the application of the circular economy concept. This paper highlights the multitude of "Rs" beyond the well-known (3Rs) Reduce-Reuse-Recycle pattern, which can be applied in various contexts to assist SMEs (Small and Medium Enterprises), organizations and even citizens successfully adopt circular economy principles. Is also explores how these "Rs" can be utilized to measure intangible aspects (something that is not there). The results indicate that more than 55Rs exist which directly involved in the circular economy framework, also considering waste management strategies. The findings of this study reveal the existence of over 100 "Rs" beyond the well-known principles of "reduce, reuse, recycle," each playing a distinct role in the development of strategies aimed at addressing waste management issues and advancing circularity towards a low-carbon society. Furthermore, the results could be useful for any policy makers, consultants, engineers, practitioners, urban planners, academics etc., in order to develop, apply, monitor, measure and improve any strategy such as circular economy strategy, waste prevention, zero waste, reuse, reduce, energy recovery etc., in the framework of circular economy principles, solid waste management and beyond.

Energy storage and key derives of octadecane thermal stability during phase change assembly with animal manure-derived biochar

The design of eco-friendly and renewable energy infrastructure is highly desirable to advance the global energy landscape. Phase-change materials (PCMs) are used to mitigate intermittency issues and reversibly store high densities of thermal energy in the form of heat during the phase transition process and provide ample potential for the advancement of renewable energy infrastructure. However, the leakage and low thermal stability of pristine PCMs along with the complicated synthesis strategies and environmental issues of the supporting materials cause significant drawbacks, thereby requiring a sustainable confining agent. In this study, a green phase change composite was developed using biowaste-derived biochar and octadecane via a vacuum impregnation strategy. The structural, morphological, thermal, and shape stabilities, as well as the chemical compatibilities of both the composite components and the octadecane-biochar composite, were investigated. The supporting biochar provides sufficient physical and thermal support besides high encapsulating capacity due to high specific surface area (135.2 m2 g-1) and predominant mesoporous proportion (86%). The results displayed that the composite material revealed a high leakage-proof capability (above the melting point of pure octadecane) with a low leakage rate (<12.5%) for a long heating time, excellent thermal stability, and high latent heat retention (89.5%) after 1000 heating-cooling cycles. The fabricated composite attained satisfactory phase change enthalpy storage, which was 130% and 168.9% higher than that of rice-husk-paraffin and garlic peel-derived carbon-paraffin, respectively, indicating promising thermal management performance. This study opens avenues for the development of green composite materials and renewable energy storage and conversion, which will play a significant role in various sectors such as building energy-saving and heat recovery systems.

Advances in Biocarbon and Soft Material Assembly for Enthalpy Storage: Fundamentals, Mechanisms, and Multimodal Applications

High-value-added biomass materials like biocarbon are being actively pursued integrating them with soft materials in a broad range of advanced renewable energy technologies owing to their advantages, such as lightweight, relatively low-cost, diverse structural engineering applications, and high energy storage potential. Consequently, the hybrid integration of soft and biomass-derived materials shall store energy to mitigate intermittency issues, primarily through enthalpy storage during phase change. This paper introduces the recent advances in the development of natural biomaterial-derived carbon materials in soft material assembly and its applications in multidirectional renewable energy storage. Various emerging biocarbon materials (biochar, carbon fiber, graphene, nanoporous carbon nanosheets (2D), and carbon aerogel) with intrinsic structures and engineered designs for enhanced enthalpy storage and multimodal applications are discussed. The fundamental design approaches, working mechanisms, and feature applications, such as including thermal management and electromagnetic interference shielding, sensors, flexible electronics and transparent nanopaper, and environmental applications of biocarbon-based soft material composites are highlighted. Furthermore, the challenges and potential opportunities of biocarbon-based composites are identified, and prospects in biomaterial-based soft materials composites are presented.

Structural characteristics and thermal performances of lauric-myristic-palmitic acid introduced into modified water hyacinth porous biochar for thermal energy storage

Water hyacinth (WH) was used to prepare biochar for phase change energy storage field to realize encapsulation and enhance thermal conductivity of phase change materials (PCMs) in this work. The maximum specific surface area of modified water hyacinth biochar (MWB) obtained by lyophilization and carbonization at 900 °C was 479.966 m²/g. Lauric-myristic-palmitic acid (LMPA) was used as phase change energy storage material, LWB900 and VWB900 were used as porous carriers respectively. Modified water hyacinth biochar matrix composite phase change energy storage materials (MWB@CPCMs) were prepared by vacuum adsorption method, with loading rates of 80 % and 70 % respectively. The enthalpy of LMPA/LWB900 was 105.16 J/g, which was 25.79 % higher than that of LMPA/VWB900, and the energy storage efficiency was 99.1 %. Moreover, the introduction of LWB900 increased the thermal conductivity (k) of LMPA from 0.2528 W/(m·K) to 0.3574 W/(m·K). MWB@CPCMs have good temperature control capability, and the heating time of LMPA/LWB900 was 15.03 % higher than that of LMPA/VWB900. In addition, after 500 thermal cycles, the maximum change rate of enthalpy of LMPA/LWB900 was 6.56 %, and it maintains a phase change peak, showing better durability than LMPA/VWB900. This study shows that the preparation process of LWB900 is the best, and the adsorption of LMPA has high enthalpy value and stable thermal performance, realizing the sustainable development of biochar.

Sustainable Interfacial Evaporation System Based on Hierarchical MXene/Polydopamine/Magnetic Phase-Change Microcapsule Composites for Solar-Driven Seawater Desalination

Solar photothermal-driven interfacial evaporation is a promising technology with great potential for wastewater purification and seawater desalination. However, intermittent solar illumination and salt accumulation are still the major roadblocks of interfacial evaporation in practical applications. Herein, we developed a novel interfacial evaporation system based on the hierarchical MXene/polydopamine (PDA)/magnetic phase-change microcapsule composites (hereafter named "MXene/PDA@TiO₂/Fe₃O₄@C₂₂-HMC") integrated with natural wood. The microcapsule composites were fabricated by microencapsulating n-docosane as a phase-change material (PCM) core in a TiO₂/Fe₃O₄ composite shell and then coating a PDA layer, followed by surface-attaching with MXene nanosheets. The obtained MXene/PDA@TiO₂/Fe₃O₄@C₂₂-HMC exhibits a good optical absorption ability, high heat energy-storage capacity, and good hydrophilicity. This enables the MXene/PDA@TiO₂/Fe₃O₄@C₂₂-HMC-based evaporator to gain a high water evaporation rate of 2.09 kg m^-2 h^-1 under one-sun illumination. A combination of the microchannels in natural wood and the tiny gap between the microcapsules results in a rapid water transportation within the evaporation system, which effectively resists salt accumulation during the evaporating process. As a result, there was no salt crystal observed from the evaporator surface in a 10 wt % NaCl solution under three-sun illumination for 8 h. More importantly, the introduction of Fe₃O₄ nanoparticles into the TiO₂ shell endows the MXene/PDA@TiO₂/Fe₃O₄@C₂₂-HMC with magnetism, greatly enhancing the reusability and separability of the developed evaporator to undertake multicycle salt accumulation and washing processes for long-term desalination use. The latent heat release of the n-docosane core offers the developed evaporator a large amount of heat energy for continuous evaporation on a semi-cloudy day, increasing the total water production by 1.17 kg m^-2 compared to the conventional evaporator without a PCM. This study provides an effective solution for intermittent solar energy utilization and salt accumulation in the solar-driven interfacial evaporation systems of seawater desalination.