Energy & Fuels最新文献

SO₂ removal in marine exhaust gas cleaningsystems isevaluated together with the CO₂ concentration. Absorbentdesign must therefore consider selective SO₂ removal inthe presence of CO₂. This study compared the SO₂ absorption performance, pH stability, and SO₂/CO₂ selectivity of NaOH, NaHCO₃, and Na₂CO₃ under SO₂-only conditions and in the presenceof 8% CO₂ using simulated marine exhaust gas. At an equalcompound molarity of 0.25 M under SO₂-only conditions,Na₂CO₃ showed the highest conversion retentionand pH stability. Its average SO₂ conversion was 99.6%,the duration at pH ≥ 7 was 98.6 min, and t₉₀ exceeded120 min. Na₂CO₃ also exhibited the highest overallgas-phase mass transfer coefficient, K_G, of 8.932 ×10^–3 mol·m^–2 · s^–1 · kPa^–1 in wetted-wall column(WWC) tests. In the presence of 8% CO₂, all three absorbentsmaintained approximately 99% SO₂ conversion. NaHCO₃ showed the highest uptake-based apparent SO₂/CO₂ selectivity of 0.213. These results guided the design ofNaHCO₃–Na₂CO₃–NaOHbuffer-type mixed absorbents. The 1%-A and 5%-B formulations wereselected from the 1 and 5 wt % groups, respectively, as candidatesfor subsequent wet scrubber evaluation. Both maintained pH ≥7 for 180 min in the bubble reactor. Their apparent CO₂ uptakes were 36.6 and 22.9 mmol·L-solution^–1, respectively. In the wet scrubber, 1%-A and 5%-B achieved SO₂ conversions of 96.5% and 94.6%, respectively, while the outletCO₂ concentration remained close to the inlet level. Thestudy identifies bicarbonate-rich, low-NaOH buffer-type formulationsthat maintain SO₂ removal while showing a small decreasein outlet CO₂ concentration.

Gel polymer electrolytes (GPEs) are emerging as a promisingsolutionfor rechargeable lithium batteries because they combine the high ionicconductivity of liquid electrolytes with the mechanical stabilityand enhanced safety of solid polymer systems. GPEs immobilize liquidcomponents within a polymer matrix while maintaining efficient ionicconductivity and electrochemical performance. This review discusseshow in situ polymerization has emerged as a promising fabricationstrategy for developing high-performance gel polymer electrolytes(GPEs) with enhanced safety, improved interfacial compatibility, andsuperior electrochemical stability. It further highlights recent advancementsin GPE design, with particular emphasis on electrode–electrolyteinterphase engineering through cathode surface modification and structuraloptimization. Special emphasis is given to the formation, stability,and improvement of the electrode–electrolyte interphase, whichplay critical roles in suppressing electrolyte decomposition and stabilizingbattery performance. Furthermore, the performance of GPEs under extremeenvironments, particularly low-temperature conditions, is criticallydiscussed, including the influence of low temperature on Li⁺ ion transport kinetics and solid electrolyte interphase (SEI) stability.Strategies to overcome these limitations are also been summarized.In addition, advanced characterization techniques such as electrochemicalimpedance spectroscopy (EIS), X-ray photoelectron spectroscopy, andtransmission electron microscopy are highlighted for understandingthe dynamic, chemical, and structural evolution of interphases duringcycling. This review also outlines the future prospects and majorchallenges associated with GPEs and provides conceptual strategiesfor the development of safe and high-performance lithium batteries.

We estimate the solubility of wateras an impurity in fluid CO₂ by calculating the chemicalpotential from intermolecularinteractions. The evaluation is conducted across a broad range oftemperatures and pressures relevant to CO₂ transport andstorage. The formation of hydrate from impurity of water reduces thesolubility relative to the value expected for fluid CO₂ coexisting with the metastable aqueous solution without hydrateformation. The solubility of water obtained shows good agreement withexperimental measurements and model calculations. Compression leadsto a lower solubility in a range of the gaseous state when the solubilityis expressed in the conventionally used mole fraction. We show thatthis is merely an apparently strange behavior and disappears by changingthe unit to molarity. The molarity-based solubility is beneficialnot only for the present study to understand temperature and pressuredependence of solubility in terms of intermolecular interactions butalso for correlating it with the driving force for water-induced corrosion.These fundamental insights into the phase equilibria of fluid CO₂ and water are valuable for technological development to preventpipeline blockages caused by hydrate formation and to mitigate water-inducedcorrosion in CO₂ transport and storage.

Metal cyanamides represent an emerging class of functionalsolidswhose properties extend beyond those of traditional oxides and sulfides.While the dianionic [NCN]^2– moiety shares the samecharge as O^2– and S^2–, givingrise to structural similarities with established metal chalcogenides,its inherent electronic delocalization and dynamic bonding flexibilitydistinguish it from conventional ligands. Crucially, the reversibleinterconversion between distinct bonding configurations within theNCN framework in specific metal cyanamides provides opportunitiesfor regulating redox activity and electronic transport. This reviewsummarizes recent advances in understanding the structure–propertyrelationships of metal cyanamides, covering rational synthesis andtheir emerging applications in catalysis and rechargeable batteries.We highlight how the dynamic nature of the cyanamide ligand facilitatesmultifunctionality, positioning these architectures as versatile platformsfor next-generation catalysis and energy technologies while identifyingcritical challenges and opportunities for future materials design.

Solar photovoltaic (PV) is recognized as one of the effectivepathwaysto achieving carbon neutrality, receiving extensive advocacy and themost widespread implementation in China. However, the expansion ofthe photovoltaic industry has created significant challenges for wastemanagement. Current research on the comprehensive resource potentialand sustainable benefits of decommissioned PV systems in China remainsinsufficient, particularly when climate commitments and PV industrydevelopment stages are considered together. Accordingly, this studyproposes a comprehensive evaluation framework to assess the multidimensionalsustainable benefits of decommissioned PV recycling across integratedscenario combinations. The results indicate that (1) by 2050, cumulativedecommissioned PV will range from 1164.2 to 1402.7 GW, generating6.43 × 10⁷–7.86 × 10⁷ MT ofresource potential. (2) An estimated 93.83% of the PV waste may consistof PV modules, 6.04% may be inverters, and 0.13% may be cables andbrackets. Among these, glass (61%), aluminum (16%), and steel (14%)are projected to constitute the largest proportions. (3) Recyclingdecommissioned PV could generate cumulative net economic benefitsranging from CNY 903.49 to 1088.60 billion (USD 140.40 to 161.99 billion),save between 2.19 × 10⁸ and 3.81 × 10⁸ GJ of primary energy, reduce carbon emissions by 111.44 to 142.05million tons of CO₂-eq, decrease wastewater generationby 2.52 to 3.43 billion m³, and prevent the accumulationof solid waste by 47.27 to 56.95 billion tons. This study offers valuableinsights into photovoltaic waste management and recycling in China,as well as guides other countries facing challenges in the disposalof decommissioned PV systems.

A 10-month gas production test from a gas hydrate-bearingsandreservoir was successfully conducted on the Alaska North Slope tobetter understand reservoir depressurization-based gas production.The JOGMEC-DOE-USGS Collaborative Gas Hydrate R&D Project in Alaskawas implemented collaboratively by Japan Organization for Metals andEnergy Security (JOGMEC) under the MH21-S R&D consortium, U.S.Department of Energy (DOE) National Energy Technology Laboratory (NETL),and U.S. Geological Survey (USGS), continuing over a quarter centuryof joint research. Using findings from the “Stratigraphic TestWell” drilled in 2018, a testing program was designed withtwo production wells and a geoscience data acquisition well supportedby “built-for-purpose” surface production test facilities.During the operations, testing was conducted in only one of the dedicatedproduction test wells, with production monitoring being conductedin the other three test site wells. Lessons from past field testsin Japan, the U.S., and Canada informed key system designs such assand control, artificial lift, and sensor installations (temperature,pressure, strain, and acoustic). Production testing began on September19, 2023. Despite periodic disruptions due to artificial lift systemproblems, the tested gas hydrate-bearing reservoir was subjected todepressurization for a total of 216 days, which included a periodof stable borehole pressure drawdown of ∼400 psi (from an initialin situ pressure of 1250 psi) that was maintained for over two months,allowing continuous data collection. In the test’s final phase,an alternative artificial lift system was installed to achieve lowerbottom-hole pressures. Key findings from the 2-month continuous productionperiod at constant bottom-hole pressure include (1) stable production,showing no indication of either increases or declines in productionrates; (2) pressure and temperature impacts were observed in all monitoringwells, indicating the rate and nature of hydrate dissociation; and(3) gas–water ratio (GWR) averaging around 600 m³/m³─far exceeding values from previous short durationtests or from numerical simulations.

We present an ion-specific parameterization of the electrolyteCubic-Plus-Association (eCPA) equation of state, which we refer toas ms-eCPA, for phase equilibria of CO₂ and CH₄ in multisalt aqueous brines containing Na⁺, Cl^–, K⁺, Ca²⁺, Mg²⁺, and SO₄^2–. The model includes a Soave–Redlich–Kwongphysical term with a Huron–Vidal mixing rule, Wertheim 4C associationof water with CO₂ cross-association, and Debye–Hückelplus Born electrostatic contributions on an ionic basis; the staticpermittivity is closed self-consistently through the Onsager–Kirkwoodrelation. The parameterization is hierarchical─each level ofadded physical description (nonpolar fluids, the associating solvent,ions in the solvent, gases over brine) introduces only parametersfitted to that level’s own data─with the top-level gas–ioninteraction energies and ion volume translations calibrated against1,931 experimental CO₂–brine VLE points in fivesalts (T = 283–473 K, P =1.3–1200 bar, m_s = 0.09–6 mol kg^–1), 581 CH₄–brinepoints in six salts (T = 298–598 K, P = 4–1379 bar, m_s = 0.25–6 mol kg^–1), and 905 high-accuracybrine densities (T = 283–473 K, P = 9–686 bar). A colligative verification of the inheritedion parameters against the Pitzer osmotic-coefficient standard uncovers,and corrects, two defects in the published ion set (the Ca²⁺ parameters and the Mg²⁺ polarizability). Across the parametrizedrange, at salt molalities to 6 mol kg^–1, the modelpredicts CO₂ solubility to within 4.3–11.1% AAREper salt and CH₄ solubility within 1.6–10.2% AAREper salt, reproduces brine density across the full salinity and temperaturerange through a temperature-dependent ion-specific Pénelouxvolume translation with a single ion-additive coefficient set, predictsCO₂ solubility in mixed-salt brines with no mixed-brinetuning, and predicts measured calorimetric enthalpies of CO₂ dissolution in water and NaCl brines to 0.6 kJ mol^–1 with no adjusted parameters. The parameterization provides the thermodynamicbasis for subsurface CO₂ sequestration and CH₄ production in realistic formation brines. In a separate study, themodel is paired with robust two- and three-phase stability and flashcomputations and extended to N₂, H₂, C₂H₆, C₃H₈, and CH₄–CO₂ gas mixtures.

Theefficiency of CO₂-enhanced oil recovery (EOR) inshale reservoirs is critically influenced by formation water and thecomplex chemistry of the crude oil. However, the roles of componentsin shale oil and its underlying mechanisms are lacking. In this work,molecular dynamics simulations were performed to investigate the CO₂ flooding process in water-bearing shale nanopores, comparingrepresentative nonpolar and polar multicomponent oil models. The resultsreveal that nanopore oil displacement efficiency is governed jointlyby shale oil composition and water content, with polarity being thepredominant factor. Specifically, nonpolar oil shows a monotonic decreasein efficiency with water content, whereas polar oil exhibits persistentlylower efficiency that declines gradually with increasing water content,attributed to the tenacious hydrogen-bonding adsorption of heteroatomicspecies. Water reduces CO₂ adsorption near the quartz surfaceand promotes clustering of oil components such as hexadecane, therebyincreasing transport resistance. For polar oil, recovery is consistentlylower and also declines with increasing water content, governed bythe tenacious adsorption of heteroatomic compounds via hydrogen bonding.Amphiphilic molecules such as 1-nonanethiol act as molecular bridges.The thiol groups anchor strongly to the surface, while their alkylchains link to nonpolar components via van der Waals interactions,forming a resistant network. Additionally, hydrogen bonding amongpolar components leads to stable aggregates that further restrictCO₂ access to the oil phase. This study offers a theoreticalbasis for optimizing CO₂-based recovery processes in water-bearingshale reservoirs rich in polar components.

Determining the concentrations of rare earth elementsand yttrium(REY) in coal is essential for evaluating coal-hosted critical metalresources and understanding their geochemical controls. However, conventionallaboratory analyses are costly, time-consuming, and spatially sparse,limiting regional-scale assessment. In this study, we compiled 527coal samples from 30 coalfields across China’s five major coal-bearingregions and developed an explainable machine learning framework forREY prediction. Unlike previous site-specific models, this frameworkintegrates feature selection, Bayesian optimization, and SHAP interpretationfor REY prediction at a broad regional scale. After data preprocessing,multicollinearity diagnosis, and correlation-based feature selection,16 predictors were retained for model construction. Four ensembleregression models, including Random Forest (RF), Extra Trees (ET),CatBoost (CAT), and Gradient Boosting Decision Tree (GBDT), were optimizedusing Bayesian hyperparameter search and 5-fold cross-validation.The ET model achieved the best test-set performance among the fourensemble models, with RMSE = 39.962, MAE = 29.669, and R² = 0.716, although predictions for highly enriched samples remaineduncertain because of the long-tailed REY distribution. SHAP analysisidentified Ga as the most influential predictor, followed by geologicalage and P₂O₅, suggesting that clay-related terrigenousinput, stratigraphic context, and minor phosphate-associated phasesmay jointly influence model-predicted REY enrichment. These resultsdemonstrate that the proposed framework can serve as an effectiveprescreening tool to prioritize coal samples for detailed REY analysis,while independent validation is recommended for high-value targetareas.

Transition-metal selenides (TMSes) show considerablepotentialas anodes of sodium-ion batteries, benefiting from their diverse redoxreactions and large theoretical capacities. Despite these merits,TMSes suffer from drastic volumetric changes and sluggish electrontransport, leading to a degraded cycling stability and poor rate performance.Herein, an integrated CoSe₂@NC nanoarchitecture was developedthrough a Co-hexamethylenetetramine precursor-mediated selenizationstrategy, yielding ultrafine CoSe₂ nanoparticles encapsulatedwithin interconnected nitrogen-doped carbon nanosheets. The two-dimensionalnanosheet morphology maximizes the accessible electrochemical interfaceand facilitates rapid Na⁺ migration, while the nitrogen-dopedcarbon nanosheet serves as a conductive network for efficient electrontransport and a structural scaffold that accommodates the volumetricvariation. Benefiting from this synergy, CoSe₂@NC deliversa considerable reversible capacity, superior rate capability, androbust cycling capability. Quantitative kinetic analyses reveal thatthe superior performance originates from dominant pseudocapacitivecharge storage, lowered interfacial impedance, and accelerated Na⁺ diffusion. Additionally, CoSe₂@NC exhibits a competentperformance when assembled into sodium-ion capacitors, further demonstratingits potential for practical sodium-based energy storage.