Green Energy and Resources最新文献

This study investigated rice straw hydrothermal carbonization (HTC) in water, optimizing operating conditions to enhance solid carbon content and nitrogen content in hydrochar. Additionally, we conducted hydrothermal co-carbonization (co-HTC) of rice straw and acid whey, achieving significant improvements in hydrochar properties. Co-HTC resulted in a 53.6% increase in HHVs, 20.0% higher yield, and a 42.7% rise in carbon content, accompanied by notable reductions in ash content. Nitrogen content increased by 26.0%, P content by 12.7 times, and K content by 27.6%. Analytical techniques revealed promising modifications, indicating potential applications of hydrochar in solid fuel or organic fertilizers, thus contributing to a circular bioeconomy in agricultural waste management.

The Chinese new energy vehicle (NEV) industry has developed rapidly, which has become one of the largest NEV markets in the world. The Chinese government has played a pivotal role in supporting and promoting the NEV industry, leading to significant advancements in policies, technology, infrastructure, industrial chain, and market development. This support has been evident through the implementation of numerous favorable policies, including increased support in finance, taxation, and technology innovation, as well as initiatives to promote research, development, and application of NEV products. Furthermore, subsidy policies have been introduced to incentivize consumers to purchase NEVs and enhance their competitiveness in the market. Additionally, regulations mandating a certain proportion of NEV production and sales for automakers have been put in place, contributing to the widespread advancement of the Chinese NEV industry. While the Chinese NEV industry has seen substantial growth, it also faces challenges and opportunities. To further its development, it is essential for vehicle manufacturers to prioritize technological innovation, the government to continue introducing supportive policies, users to increase environmental awareness, and for collaboration between academia and industry to drive research efforts. The development of the Chinese NEV industry is not only in line with the global trend of environmental protection, energy security, and industrial transformation, but also an important link in promoting the progress of the global NEV industry.

The MgO-activated SiO₂ system demonstrates potential for a low carbon footprint throughout its lifecycle and is characterized by favorable mechanical properties, low alkalinity, and a high specific surface area, which shows promise in replacing traditional silicate cement in certain applications. The current system faces challenges such as slow early hydration rate, low early strength, and inadequate volume stability, which impede its further development and application. The MgO-activated SiO₂ system was improved and optimized through multiple tests using carbonation (CO₂ gas/NaHCO₃ solution), nanomaterials (whiskers), and fiber (organic/inorganic fiber) composite reinforcement. This paper provides an overview of the hydration mechanism of the MgO-activated SiO₂ system, explores modifications and control measures based on this mechanism, and discusses the potential applications and future development of the MgO-activated SiO₂ system.

This research presents a facile and inexpensive method for synthesizing ZnO nanoparticles using Nauclea latifolia fruit extract as a bioreductant and stabilizer. The prepared particles were characterized using some analytical techniques, including X-ray diffraction (XRD) for crystallinity and phase identification, scanning electron microscopy (SEM) to study surface morphology, Fourier transform infrared (FTIR) spectroscopy for functional groups analysis, transmission electron microscopy (TEM) for grain size analysis, UV–Vis spectroscopy for optical properties, and Brunauer-Emmett-Teller (BET) for surface area analysis. XRD analysis revealed a hexagonal wurtzite structure with an average crystallite size of 14.40 nm. FTIR showed absorption peaks at 3659, 1341, and 460 cm⁻¹, corresponding to hydroxyl, carboxylic, and Zn–O, respectively. SEM image showed an agglomerated surface morphology with a flower-like shape. TEM estimated the particle size range to be 12.54–17.35 nm. UV–Vis scanning showed a broad peak at 373 nm. BET revealed 277.420 m²/g as the specific surface area. A batch adsorption experiment conducted on the performance of the nanoparticles for methyl green (MG) removal from aqueous solution showed highest efficiency of 99.96% at 60 min agitation time and pH of 7, with 0.05 g of the ZnO NPs, confirming the efficiency of the particles. The results of adsorption modelling revealed that the adsorption data were best fit to Freundlich isotherm and general-order kinetic models. Thermodynamic investigation confirmed the adsorption process as spontaneous, feasible, endothermic, and physical. Finally, the simplicity of the synthesis method and the performance evaluation of the ZnO nanoparticles indicate that an efficient and cost-effective adsorbent for MG recovery from aqueous solution has been successfully prepared.

In the domains of low/zero carbon energy, the ship energy storage system, coupled with phase-change storage and release technology, holds significant importance. The utilization of a flat micro-heat pipe as the primary heat transfer element prompts the development of a test platform and a transient heat transfer model for the heat storage device. This is in response to existing challenges such as a single structure, poor temperature uniformity, and low thermal efficiency in current heat storage technology. The study delves into the impact of varying temperatures and flow rates of heat transfer fluids on the overall performance of heat storage devices and heat transfer efficiency. The findings highlight that the staggered double plate micro-heat pipe structure can enhance total heat storage by 11%, average heat storage power by 19%, and heat storage efficiency by 21% compared to the heat storage device with a single flat micro-heat pipe structure. It becomes evident that the heat storage device with the staggered double heat pipe structure outperforms its counterpart. Additionally, Temperature and flow velocity play pivotal roles in determining the heat transfer performance of phase change materials. As the temperature difference between the heat transfer fluid and the phase change material increases, both the phase transition rate and the equivalent Nusselt number also rise, providing a crucial foundation for examining the heat transfer characteristics of phase change materials during different stages of phase transition.

With the increasingly severe problem of air pollution and energy crisis, new energy power generation technology in ship has quickly become the focus of attention. Compared with traditional ships, hybrid shipboard microgrid systems can achieve pollution-free, renewable and high use value. However, the integration of electricity-gas-heat in hybrid energy shipboard microgrid system also poses challenges to current optimization methods. Therefore, this paper develops a bi-level optimization dispatch model for hybrid shipboard microgrid system based on multi-objective particle swarm optimization algorithm. Taking the diesel generators, photovoltaic generation system, energy storage system (ESS) and thermal energy storage equipment into account, a hybrid shipboard microgrid system model considering electricity-gas-heat coupling is constructed. Based on this, a bi-level optimization dispatch model is established to reduce total cost, GHG (GHG) emissions and lifespan loss of ESS. The upper-level model achieves the optimization dispatch of power generation equipment and loads; a lower-level optimization model with the goal of reducing the lifespan loss of ESS is constructed. The improved multi-objective and single-objective particle swarm optimization algorithms are introduced to find the optimal dispatch solutions for bi-level optimization dispatch model. Finally, simulation results show that the proposed optimization method can not only reduce the cost and GHG emissions by 8.7% and 10.9%, but also improve the cycle life of ESS by 9.2%.

Selenium has high theoretical volumetric capacity of 3253 mAh cm⁻³ and acceptable electronic conductivity of 1 × 10⁻⁵ S m⁻¹, which is considered as a potential alternative to sulfur cathode for all-solid-state rechargeable batteries with high energy density. However, the development of all-solid-state Li–Se batteries (ASSLSBs) are hindered by sluggish kinetics and poor cycling life. In this work, trigonal Se nanocrystallines are homogenously distributed in the interspace and on the surface of MXene layers (denoted as Se@MXene composite) by a novel melt-diffusion method. ASSLSBs based on this Se@MXene composite cathode exhibit large specific capacity of 632 mAh g⁻¹ at 0.05 A g⁻¹, high-rate capability over 4 A g⁻¹, and excellent cycling stability over 300 cycles at 1 A g⁻¹. The ex-situ analytical techniques demonstrate that the excellent electrochemical performance of Se@MXene cathode largely arises from structural stability with the assistance of conductive MXene and reversible redox behavior between Li₂Se and Se during the repeating charge/discharge process. Our study points out the potential of material design of Se cathode based on conducting 2D materials with good electrochemical behavior, which may accelerate the practicability of ASSLSBs.

Optimization can streamline experimental trials by evaluating the parameters and parameter interactions used as the basis for a more optimal downstream process. This study aims to optimize the microwave-assisted pyrolysis process in producing bio-oil from microalgae using response surface methodology (RSM) complemented by an investigation of the reaction mechanisms. A number of key parameters (microwave power, absorbent-to-microalgae ratio, and pyrolysis time) were fine-tuned using a face-centered central composite design. The result showed that microwave technology in slow pyrolysis could produce the bio-oil from microalgae 12 times shorter than conventional heating and quadratic model with a high precision (R² = 0.9832, R²adj = 0.9616) from RSM optimization in predicting experimental values yielded a peak bio-oil yield of 19.11% under specific conditions: 20 min of pyrolysis time, a 0.19 (w/w) microwave absorber to microalgae ratio, and 583 W power. As the complex biomass, the reaction mechanism in chlorella sp. towards this technology including decarboxylation, decarbonylation, dehydration, cracking, deoxygenation, and esterification was proved in GCMS analysis, revealing the presence of key functional groups such as aliphatic, aromatics, alcohols, nitrogenous compounds, fatty acid methyl esters (FAME) and Polycyclic Aromatics Hydrocarbons (PAHs).

Global warming poses one of the most critical challenges of the 21st century, leading to significant environmental damage. The extraction and combustion of fossil fuels release substantial amounts of greenhouse gases, thereby contributing to climate change. In response to this pressing issue, plasma-based conversion of carbon dioxide has emerged as a prominent and widely explored solution. Among the various plasma technologies, microwave plasma setups have garnered considerable attention due to their exceptional ability to decompose carbon dioxide, facilitate the dry reforming of methane and reverse water gas shift. These setups are renowned for their high degree of ionization and generation of non-equilibrium plasma, making them a clean and highly efficient method for treating greenhouse gases. However, researchers often face challenges in selecting the appropriate microwave plasma reactors. Thus, the primary objective of this paper is to provide guidance on microwave plasma setups. It is achieved by illustrating experimental configurations based on the microwave operating mechanism and presenting a classification of microwave plasma sources according to their operating principles. Moreover, specific experimental operations are discussed within the scope of our analysis, offering valuable insights to researchers in this field.

As a common industrial solid waste, fly ash requires proper processing and utilization to alleviate environmental pressure. In contrast to earlier low-value treatment methods for fly ash, such as its use in construction materials, it is more practical to explore the high-value utilization of fly ash, considering its elemental ingredient and morphological characteristics. Herein, this work comprehensively reviews the methods and research progress of extracting and preparing silica, alumina, and zeolite respectively derived from silicon and aluminum elements in fly ash. Specifically, the mechanisms and processes of various methods are elucidated in detail, and the virtues and drawbacks of the production technologies are compared to identify a more economical and environmentally friendly method. Importantly, this work first reviews the utilization of fly ash in energy storage electrode materials. Different synthesis and treatment strategies are thoroughly examined, especially in fully utilizing fly ash as a primary resource, converting it into energy storage materials. Finally, this paper summarizes the opportunities and challenges associated with the high-value utilization of fly ash.