Energy & Fuels最新文献

The development of robust hard carbon as sodium-ion batteries (SIBs) anode is often constrained by the trade-off between specific capacity, initial Coulombic efficiency (ICE), and rate performance. Here, a multiscale synergistic strategy is proposed to synthesize advanced hard carbon anodes using low-cost coal pitch as the precursor. This is achieved through a facile one-step pyrolysis process involving sodium thiosulfate as a combined sulfur source and porogen, magnesium oxide (MgO) as a hard template, and poly(vinylpyrrolidone) (PVP) as a versatile additive acting as a secondary porogen and nitrogen source. The optimized carbon material exhibits a unique structure characterized by S/N codoping, an enlarged interlayer spacing (0.385 nm), and a hierarchical pore architecture with a balanced surface area and pore volume. When employed as a SIBs anode, this electrode delivers a significant reversible capacity of 278.3 mAh g^–1 with an outstanding ICE of 83.5%, remarkable rate performance (173.7 mAh g^–1 at 3C), and excellent cycling durability. Electrochemical analysis reveals that the synergistic effects of heteroatom doping and optimized porosity enhance Na⁺ adsorption, facilitate intercalation, and improve ion transport kinetics. Furthermore, a full cell configured with this anode and a Na₃V₂(PO₄)₃ cathode demonstrates a high operating voltage and prominent stability, retaining 63.6% capacity after 2000 cycles. This work provides a viable approach to design carbonaceous materials that break the performance coupling in SIB anodes.

During surfactant flooding, the significant adsorption loss on rock surfaces often results in a lower-than-expected oil displacement efficiency when the surfactant reaches the target reservoir area. This paper proposes a novel binary composite flooding system composed of a styrene-acrylate copolymer emulsion and alkali. As the acrylate in the styrene-acrylate copolymer emulsion hydrolyzes, the composite system gradually transitions from a water-insoluble polymer nanoparticle dispersion to a polymeric surfactant. By use of the weak adsorption of polymer nanoparticles on rock surfaces, more surfactants can reach the target area. This work first optimized the preparation conditions of the styrene-acrylate copolymer emulsion and measured its static adsorption on quartz sand. Then, the solution properties of the styrene-acrylate copolymer emulsion + alkali binary composite system were studied. Finally, the injectivity and oil displacement performance of the binary composite system in different states (0, 8, and 24 h of hydrolysis) were investigated. Based on the experimental results, the recommended synthesis conditions for the styrene-acrylate copolymer emulsion are acrylate as methyl acrylate (MA), MA to styrene mass ratio of 8:2, initiator dosage of 0.2% of the total monomer mass, reaction temperature of 75 °C, total monomer concentration of 10%, emulsifier dosage of 1.2% of the aqueous phase mass, and reaction time of 4 h. Adsorption experiments showed that the adsorption of the styrene-acrylate copolymer emulsion is lower than that of commonly used surfactants. Injectivity experiments demonstrated that the binary system in different states exhibits good injectivity in cores with gas permeability ≥ 100 mD. When the core permeability was 600 mD, oil displacement experiments indicated that the 24 h hydrolyzed binary system increased the oil recovery by 23.41%, higher than the binary system in other states.

To simultaneously enhance shale oil recovery and CO₂ storage under dual-carbon objectives, this study develops a machine learning-based biobjective optimization framework tailored for CO₂-enhanced oil recovery (CO₂-EOR). Numerical simulations were first performed to quantify the impacts of key injection parameters (including injection volume, rate, timing, and number of huff-and-puff cycles) on production performance and CO₂ retention, followed by sensitivity analysis to identify the dominant controls. The simulation outputs were then incorporated into a surrogate-assisted machine learning optimization workflow that evaluates each scenario using the CO₂ retention factor (F_CCR) and net present value (NPV). The results indicate that increasing injection volume and cycle number markedly improves both oil recovery and CO₂ sequestration, whereas higher injection rates and earlier injection timing enhance short-term production but diminish CO₂ retention, highlighting an inherent trade-off between economic gains and storage capacity. The optimized scenario achieves an F_CCR of 0.1298 and an NPV of 3.34 × 10⁷ CNY, demonstrating that coordinated parameter optimization can simultaneously ensure economic feasibility and substantial geological storage. Compared to the baseline engineering design, the optimized strategy increased the NPV by 9.2% and the F_CCR by 20%. This study establishes an integrated biobjective optimization framework for shale CO₂-EOR, quantitatively elucidates the competing effects of injection timing and rate, and offers a practical, data-driven strategy for designing CO₂-EOR operations compatible with emerging carbon-neutral development targets.

Enhanced oil recovery is crucial for maximizing production from conventional reservoirs, with surfactant-induced wettability alteration being a key mechanism. Investigating the molecular-scale dynamic adsorption behavior of heteroatom-containing (N, S, O) polar molecules on sandstone surfaces contributes to surfactant-based EOR development. This study examines wettability alteration mechanisms in hydrophilic sandstone induced by polar molecules in crude oil. Experimental aging tests were conducted on Colton Sandstone using n-decane solutions containing various polar compounds (3-decylthiophene, 4-octylphenol, 4-decylpyridine, n-decanoic acid, and decyltrimethylammonium bromide). Contact angles were measured over 26 days on both dry and water-saturated samples. Molecular dynamics simulations on hydroxylated and nonhydroxylated α-quartz (011) surfaces elucidated molecular-level adsorption mechanisms. Experimental results show that on dry sandstone, 3-decylthiophene, 4-octylphenol, and n-decanoic acid induced oil-wet transition. On prewater-saturated sandstone, the preexisting water film inhibited adsorption, with only ionic DTAB and Ca²⁺-decanoic acid effectively causing oil-wetness. MD simulations revealed strong adsorption of n-decanoic acid and Ca²⁺-decanoate complexes on silica surfaces, preventing water spreading and confirming their role in oil-wetness induction. Adsorption was driven by hydrogen bonding and electrostatic interactions like Si–O coordination and Ca²⁺ bridging, with distinct mechanisms on hydroxylated versus nonhydroxylated surfaces. This combined approach provides detailed molecular-level understanding of adsorption sites and mechanisms, offering insights for targeted surfactant design to reverse oil-wetness and improve recovery efficiency in sandstone reservoirs.

With the rapid growth of smart innovations, flexible electronics recognized for their lightweight, tremendous flexibility, and extraordinary scalability are growing more integrated into our daily life. Flexible electronics, known for their lightweight, high flexibility, and seamless integration with biological and nonbiological systems, are driving advances in wearable and implantable devices. Central to this progress are flexible electrodes, which enable energy storage, sensing, and health monitoring. This review highlights the evolution of flexible electrode materials over the past decade, focusing on carbon-based systems, transition metal compounds, MXenes, conductive polymers, and metal–organic frameworks (MOFs). Advances in flexible electrolytes, including aqueous, nonaqueous, ionic, and redox gel systems, are also discussed. Key applications span health monitoring, robotics, and plant wearables. We critically analyze material advantages, fabrication challenges, and integration hurdles while outlining future prospects for scalable, biocompatible, and multifunctional electrode systems.

To address water channeling in late-stage oilfields and overcome the limitations of conventional polymeric water plugging agents, this study developed an innovative magnetic-temperature dual-responsive Fe₃O₄@SiO₂–P/O Pickering emulsion (FSP). This water plugging agent was developed using core–shell Fe₃O₄@SiO₂ nanoparticles. After grafting modification with polyethylene glycol 200 (PEG₂₀₀) and n-octyltriethoxysilane (OTES), the resulting nanoemulsifier (Fe₃O₄@SiO₂–P/O) exhibits hydrophilic–hydrophobic transition properties at 90 °C. The FSP water plugging agent was successfully prepared using these nanoparticles as an emulsifier. Experiments show the FSP emulsion is stable at room temperature but demulsifies rapidly above 90 °C. It can also be precisely separated with a magnetic field. Core displacement experiment demonstrated its excellent selective plugging ability, achieving a 94.34% water plugging rate and only an 18.8% oil plugging rate. Injectability experiments also demonstrated its deep migration capability. This research achieves temperature control over the plugging material’s hydrophilicity/hydrophobicity by manipulating the conformational changes of the surface polymers on the Fe₃O₄ nanoparticles at high temperatures, while utilizing its magnetic properties to achieve precise control over its mobility.

In the context of the global dual-carbon strategy, developing sustainable and high-performance electrode materials for supercapacitors is of great significance. In this work, a facile two-step method was employed to convert honeysuckle vine, an agricultural byproduct, into hierarchically porous activated carbon (HVAC) via precarbonization and KOH activation. By systematically regulating KOH/HVC mass ratio and the activation temperature, we elucidated the reaction mechanism of KOH etching. At elevated temperatures, KOH reacts with the carbon framework to generate K₂CO₃ and metallic K, whose continuous volatilization and migration create an interconnected pore network. The optimized sample, HVAC-6-800, exhibits a high specific surface area of 3489.04 m² g^–1, a well-developed porous structure, and oxygen doping. The HVAC-6-800 electrode delivers a high specific capacitance of 338.7 F g^–1 at 1 A g^–1, excellent rate capability (68% retention at 20 A g^–1), and outstanding cycling stability (94% retention after 5000 cycles). Symmetric supercapacitors assembled with HVAC-6-800 electrodes in 6 M KOH and [BMIM]BF₄ electrolytes achieve energy densities of 16.85 Wh kg^–1 (150 W kg^–1) and 49.0 Wh kg^–1 (377 W kg^–1), respectively, along with superior cycling performance (97% capacitance retention after 8000 cycles in KOH). This work demonstrates that honeysuckle vine-derived porous carbon is a promising, sustainable, and high-performance electrode material for supercapacitors.

Salt precipitation during geological carbon storage in saline aquifers, caused by the evaporation of formation water into the gas phase, is a major challenge in carbon capture and storage (CCS) projects. A comprehensive understanding of the mechanisms governing salt precipitation is essential for advancing carbon sequestration in saline formations. One key phenomenon that exacerbates pore-throat blockage and promotes localized salt precipitation is capillary-driven backflow, which transports brine from undried regions toward the drying front, contributing to salt accumulation. Although several studies, including numerical simulations and laboratory experiments, have explored this phenomenon, the interplay between capillary backflow and reservoir heterogeneity remains poorly understood. Micromodel experiments─with their visualization capability─have improved the understanding of capillary backflow. However, many of these studies rely on simplified models of reservoir rock, a limitation also seen in numerical simulations. Past efforts to investigate the role of heterogeneity often fall short, sometimes using dual-permeability models as proxies rather than true heterogeneous systems. In this work, the simultaneous effects of capillary forces (which induce capillary backflow) and heterogeneity are systematically examined. CO₂ injection experiments were conducted in both homogeneous and heterogeneous micromodels under three different injection rates. The results reveal that reservoir heterogeneity significantly intensifies salt precipitation, and at lower injection rates, salt precipitates locally, causing greater formation damage. Furthermore, this study shows for the first time that the continuity of water films─controlled by pore geometry─plays a key role in capillary backflow efficiency.

The biomass chemical looping gasification pilot-scale test equipment was designed and built independently. Water hyacinth was selected as a biomass material, and red mud was used as an oxygen carrier. The effects of biomass moisture content (11.31%–58.33%), reaction temperature (800–950 °C), and steam flow rate (1.2–2.1 kg/h) on the product distribution and gasification efficiency were systematically studied. The results showed that the increase of moisture content could promote the generation of H₂-rich syngas, while having negative effects on gas yield and lower heating value (LHV). As the moisture content increased from 11.31% to 58.33%, the H₂ concentration increased from 38% to 64%, but the total gas yield and LHV decreased from 0.94 N m³/kg and 12.65 MJ/Nm³ to 0.60 N m³/kg and 8.42 MJ/Nm³, respectively. The total gas yield rose from 0.80 N m³/kg at 800 °C to 0.94 N m³/kg at 950 °C as the temperature increased. While the cold gas efficiency exhibited a trend of initial increase followed by decline, reaching its peak of 88.38% at 900 °C. The increase in the steam flow rate enhanced the total gas yield and reached a maximum of 0.99 N m³/kg at 2.1 kg/h. The carbon conversion rate also increased first and then decreased, reaching a maximum of 89.95% at 1.8 kg/h. The optimum conditions for comprehensive performance were obtained with a moisture content of 11.31%, reaction temperature of 900 °C, and steam flow rate of 1.8 kg/h. The carbon conversion rate, cold gas efficiency, and effective gas proportion could reach 89.95%, 88.38%, and 76.36%, respectively.

Unprecedented levels of population growth, urbanization, and industrialization have occurred in the 21st century, and with them has come an increase in demand for energy as well as a rise in the production of solid and plastic wastes. Heterogeneous catalysts designed from abundant and readily available solid waste provide a sustainable recycling strategy for industrial-scale applications. Nonetheless, the impact of purification techniques and raw material compositions may aid in tailoring the development of a robust catalyst for specific applications. Waste-derived catalysts have demonstrated capability in biofuel refining applications such as biodiesel synthesis, pyrolysis of lignocellulosic biomass, and waste plastic into oils. The first part of this review focuses on metal oxides that make different solid wastes viable for catalyst design and development, and the second and third parts cover the application of waste-derived catalysts in the catalytic upgrading of waste plastic and lignocellulosic biomass pyrolysis oils into fuels. For the industrial scalability of these waste-derived catalysts, their activity, stability, reusability, and regenerability in the context of upgrading oils derived from the pyrolysis of biomass and waste plastics were critically evaluated. Waste-derived heterogeneous catalysts were found to perform comparably to conventional industrial catalysts such as zeolite-based and hydrotreating (e.g., Ni-Mo/Al₂O₃) catalysts. Particularly, Red mud-derived catalyst has demonstrated cost-effectiveness and sustainable catalytic upgrading of bio-oil and waste plastic pyrolysis oil into fuel-range hydrocarbons (28–40 wt % gasoline, 35–50 wt % diesel fractions, and chlorine content less than 0.1 wt %). This research promotes the design and development of heterogeneous catalysts from industrial, municipal solid waste, biomass and agricultural residues, eggshells, seashells and bones, and e-waste by combining synthesis and purification methodologies to recover mixed metal oxide materials to bridge existing supply gaps. Consequently, their applications in the catalytic upgrading of oil produced from the pyrolysis of waste plastics and lignocellulosic biomasses into fuels offer economic, environmental, and energy security benefits.