Energy & Fuels最新文献

Lithium–sulfur (Li–S) batteries hold great promise as future energy storage solutions owing to their low cost and environmental friendliness. Nature provides biomass materials that can serve as carriers for sulfur, featuring micropores, mesopores, and hierarchical pore structures. In this study, we utilized corncob-originated activated porous carbon (CPC), abundant agricultural wastes (AWs), as the sulfur host to prepare MXene (Ti₃C₂T_x) enhanced hierarchical bioderived porous electrode. The synthesis and function of CPC for Li–S batteries are presented, and the electrochemical effects of structural diversity, porosity and surface heteroatom doping of the Mxene in Li–S batteries are discussed. Brunauer–Emmett–Teller (BET) analysis revealed that CPC exhibited a specific surface area (SSA) of 1015.59 m² g^–1 and a total pore volume of 0.44 cm³ g^–1, significantly higher than those of P-CPC (35.30 m² g^–1 and 0.022 cm³ g^–1). Furthermore, the CPC/MXene@S composite electrode demonstrated an impressive initial discharge capacity of 1358 mAh g^–1 at 0.1C and retained a reversible capacity of 695 mAh g^–1 after 500 cycles at 0.2C, with a capacity decay rate of only 0.05% per cycle. Additionally, it showed excellent rate performance, delivering a capacity of 776 mAh g^–1 even at a high current density of 2C. The superior electrochemical performance of this composite electrode can be attributed to MXene’s effective adsorption of polysulfides. This study provides a new methodology for utilizing waste biomass as a carrier for sulfur electrodes. In addition, the economic benefits, new trends and challenges are also proposed for further design excellent AWs for Li–S batteries.

The adsorption/desorption features of coal seams affect the productivity of coalbed methane (CBM) wells. In light of the gas content and isothermal adsorption data of coal in different depth sequences in the Daning–Jixian (DJ) block, the adsorption characteristics and control factors of coal seams in the study area as well as the vertical variation characteristics of gas content and gas saturation are analyzed. Based on the connotation of isothermal adsorption curves, multiple indicators, such as the movable total gas content (MTGC) and desorption efficiency (DE), are proposed to evaluate the mobility and gas production potential of coal reservoirs under the constraint of depth effects. The findings reveal that increasing geo temperature, pressure, and coal rank play a role in the adsorption traits of coals, while the gas content and saturation tend to increase for shallow to deep depths. For deep seams in the western slope zone, the gas saturation is greater than 100%, forming an oversaturated gas reservoir rich in free gas. Under the same abandonment pressure conditions, the proportion and content of effective movable total gas gradually increase as the depth increases, while the proportion and content of residual adsorbed gas gradually decrease. The pressure at the key desorption nodes increases as the depth increases. However, the production case analysis shows that the initial desorption efficiency (IDE) of the adsorbed gas in the oversaturated reservoirs was low, but its gas production time was long, the total gas production was large, and the gas production slowly increased to the peak of the adsorbed gas, meaning that the gas production potential is high, which is more conducive to the development in general.

In recent years, spinel oxides (i.e., AB₂O₄) have gained attention for energy and fuel applications due to their inherent structural stability and unique functional properties, making them strong contenders for advancing different energy systems. The intrinsic structural flexibility of AB₂O₄ permits targeted modification of their electrical, magnetic, chemical, thermal, and structural characteristics to meet various operational requirements. This review focuses on recent research (from 2020 to the present) on how such a big family of materials can be tailored and leveraged for use in energy and fuel applications, such as batteries, supercapacitors, fuel cells, electrolysis, CO₂ conversion, and chemical catalysts. We focus on experimental strategies for modifying spinels to better exploit their key attributes while minimizing known drawbacks. This review aims to evaluate the use of key modification approaches to tune the structures and properties of AB₂O₄, including doping, defect engineering, and nanostructuring, to drive improvements in energy and fuel applications. Additionally, we discuss diverse emerging applications where continued innovation could significantly enhance the role of spinels in advanced energy systems.

This study investigated the simultaneous effects of four variables─column packing, diffuser pore size, biogas flow rate, and liquid height─on the mass transfer of CO₂ and CH₄ in bubble columns for photosynthetic biogas upgrading. Two bubble columns were used: an empty column and a column packed with granular media, both filled with wastewater-derived microalgae. The microalgal suspension was obtained from a high-rate algal pond that treated the anaerobic effluent from an upflow anaerobic sludge blanket reactor fed with urban wastewater. The results indicated a direct relationship between the methane–water volumetric mass transfer coefficient (K_La) and both biogas flow rate and liquid height in both columns. Although higher K_La values were observed at increased biogas flow rates, higher masses of methane were transferred to the liquid phase at lower flow rates due to longer contact times. Additionally, lower biogas flow rates enhanced CO₂ transfer, driving it toward saturation in the liquid phase, whereas extended contact times led to oxygen enrichment of the biogas. The packed column achieved higher K_La, suggesting that the granular media fragmented biogas bubbles, preventing coalescence and improving gas–liquid contact. However, connecting a coarse bubble diffuser to the packed column proved disadvantageous due to high oxygen enrichment and methane loss. By contrast, the use of a fine bubble diffuser in the empty column improved biogas energy potential, reduced oxygen enrichment, and enhanced methane retention, resulting in a more efficient upgrading process. Overall, this study revealed a positive energy balance under the tested conditions and demonstrated that optimizing diffuser and column design is crucial for enhancing the energy efficiency of biogas upgrading.

The Fengcheng Formation in the Mahu Sag of the Junggar Basin exhibits complex depositional systems containing heterogeneous hydrocarbon resources across distinct subregions. Shale oil accumulations predominantly occur in the northwestern basin sector, where significant variations in reservoir-oil-bearing potential arise from depositional heterogeneity and differential pore structure development within target intervals, presenting substantial challenges for commercial development. This study systematically investigates pore architecture and its controlling factors in Fengcheng Formation reservoirs, with a specific focus on sedimentary microfacies, mineralogical composition, and diagenetic alterations. A multidisciplinary characterization approach integrating high-pressure mercury intrusion (HPMI), low-temperature nitrogen adsorption, field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and conventional petrophysical analysis was employed to evaluate reservoir characteristics across sedimentary microfacies. Key findings reveal pronounced petrophysical contrasts among microfacies: (1) displays low porosity primarily controlled by intense mechanical compaction and cementation processes, resulting in substantial pore space reduction and low permeability. (2) Tempestite microfacies: demonstrates favorable pore characteristics attributed to high-energy depositional environments and carbonate dissolution, with secondary porosity generation enhancing pore connectivity through well-developed macropore networks. (3) Quiet Water microfacies: exhibits moderate porosity but restricted permeability due to pore-throat obstruction by felsic minerals and clay authigenesis, significantly limiting fluid mobility. (4) Slump microfacies: characterized by low porosity influenced by differential compaction and complex mineralogical assemblages, it leads to poorly connected pore systems with correspondingly low permeability. This study establishes a systematic analytical framework for pore structure evaluation in heterogeneous reservoirs of the Fengcheng Formation and elucidates the critical controls exerted by sedimentary microfacies differentiation, mineralogical constraints, and diagenetic overprinting on reservoir quality evolution.

Reactive batch distillation combines the advantages of reactive distillation with the flexibility of batch distillation. In this study, the production of cyclopentadiene by cracking dicyclopentadiene in pyrolysis gasoline using reactive batch distillation was studied. The reaction kinetics of dicyclopentadiene cracking were determined by in situ GC-MS analyses, and vapor–liquid equilibrium data were obtained for a multicomponent pyrolysis gasoline mixture at three different temperatures and pressures experimentally by using single-stage distillation steps. The validated reaction kinetics and vapor–liquid equilibrium data were utilized in the Aspen Plus BatchSep module to simulate the reactive batch distillation of cyclopentadiene from pyrolysis gasoline. The effects of operating pressure, steam flow rate, and reflux ratio on the distillation time and recovery ratio were analyzed. Our simulation studies showed that cyclopentadiene with 90 wt % purity can be produced by a single batch distillation column in two steps under 0.9 and 1.5 bar pressure with 76.5% overall yield.

The coal deformation, damage, and gas migration under a coupled temperature and effective stress environment are pivotal for coal seam mining and gas extraction. A permeability model that integrates the effects of temperature, effective stress, and damage is established in this study. A series of thermal-hydro-mechanical (THM) coupling experiments are conducted to investigate the mechanical behaviors, permeability evolution, and damage evolution based on acoustic emission. The roles of effective stress and temperature in jointly influencing the mechanical behavior and permeability characteristics of coal are thoroughly analyzed, with a focus on the extent of their respective contributions. The results indicate that during cyclic loading, the elastic modulus initially increases and then decreases, while the AE ring count exhibits a cyclic pattern of first rising and then falling. The cumulative ring count follows a “ladder-like” growth trend. Moreover, the elastic modulus and peak strength progressively decline under growing temperature, whereas the maximum AE ring count and cumulative ring count increase. In the volumetric compaction stage, permeability decreases with axial strain, and higher temperatures result in a smaller reduction in permeability. Permeability increases during the dilation stage, with a more pronounced increasing trend observed at higher temperatures. The accuracy of the proposed permeability model has been thoroughly confirmed. Furthermore, the contribution of effective stress on gas seepage is significantly greater compared to temperature for the same burial depth increment. Finally, the mechanisms by which stress and temperature influence permeability are discussed in detail.

NH₃ selective catalytic oxidation (NH₃-SCO) is an effective technology for solving the ammonia slip problem from NH₃-fueled engines. However, achieving high activity and high N₂ selectivity during catalytic reactions remains a significant challenge. Herein, the W/CeZrO_x catalyst was modified with varying Cu loadings (5, 10, 20, and 40 wt %) to improve its low-temperature activity. Among these, 20Cu–W/CeZrO_x (20 wt %) exhibited the optimal catalytic performance, achieving 97% NH₃ conversion at 300 °C. On the other hand, the NH₃ conversion of the W/CeZrO_x catalyst was only 55% even at 400 °C. The N₂ selectivity of the 20Cu–W/CeZrO_x catalyst was higher than 82% over a wide temperature range of 225–400 °C. Various characterization techniques revealed that Cu introduction increased the proportion of surface-adsorbed oxygen on the W/CeZrO_x catalyst, which played a crucial role in enhancing NH₃-SCO activity. In situ DRIFTS results indicated that both W/CeZrO_x and 20Cu–W/CeZrO_x catalysts followed an internal selective catalytic reduction (i-SCR) mechanism in the NH₃-SCO reaction. The abundance of surface-adsorbed oxygen facilitated the overoxidation of NH₃ species on the surface of the 20Cu–W/CeZrO_x catalyst to NO, thereby accelerating the NH₃-SCO reaction. Meanwhile, NO further reacted with the amide (−NH₂) to produce harmless N₂ and H₂O, and only a small amount of NO was further oxidized to form N₂O and NO₂, which contributed to maintaining excellent N₂ selectivity.

The design and preparation of highly efficient and stable cocatalysts are critical for improving the photocatalytic CO₂ reduction performance. A traditional cocatalyst consists of metal nanoparticles that facilitate the separation of photoinduced electron–hole pairs and the reduction of protons. In this research, the Pt₃Co alloy nanocluster cocatalyst was loaded onto Mo₂C MXene to enhance photocatalytic CO₂ reduction activity and CO selectivity. As anticipated, the optimized Pt₃Co/Mo₂C-5 exhibited a 3.2-fold increase in CO₂-to-CO conversion efficiency compared to individual Mo₂C MXene, with selectivity rising from 63.94% to 81.75%. The photoelectrochemical experiments and in situ transmission FTIR results further validated that the Pt₃Co/Mo₂C catalyst possesses excellent charge separation efficiency, providing more reduction active sites for CO₂ reduction reactions. This work offers novel insights into the utilization of alloy clusters and Mo₂C MXene in photocatalytic CO₂ reduction.

Green hydrogen is anticipated to be instrumental in decarbonizing sectors that are challenging to electrify and in facilitating the storage and distribution of renewable energy. While technological advancements in water electrolysis have been extensively researched, the impact of operational scenarios on the levelized cost of hydrogen (LCOH) is less explored. Here, we exhaustively assessed all operational scenarios─varying electricity supply (grid-connected vs off-grid), battery storage inclusion, utilization rates, and maintenance strategies─and calculated their LCOH via techno-economic analyses. Our findings reveal that operational scenarios can reduce LCOH more significantly than technological improvements alone. Historical trends in LCOH indicate that lower off-grid renewable electricity costs are pivotal in decreasing production expenses, whereas electrolysis efficiencies remain relatively constant. Scenarios employing off-grid renewable energy without battery storage, coupled with low-capital-expenditure electrolyzers and optimized maintenance, offer the greatest cost benefits. This framework provides a basis for green hydrogen system design, highlighting the critical role of operational optimization in accelerating cost-effective deployment.