Search Results (5,273)

Blast furnace (BF) ironmaking is a complex multiphase process involving gas–solid flow, heat transfer, chemical reactions, burden movement, and phase transformation under high-temperature conditions. Since many internal states of the blast furnace cannot be directly observed during operation, numerical simulation and mathematical modeling have become important tools for understanding furnace behavior and optimizing operational parameters. This paper reviews recent advances in blast furnace numerical simulation and internal state reconstruction methods. Existing approaches, including packed-bed flow models, cohesive zone reconstruction methods, burden distribution models, and temperature field prediction methods, are summarized and discussed. In addition, the evolution of blast furnace mathematical models from early one-dimensional steady-state formulations to modern three-dimensional multifluid and hybrid simulation approaches is reviewed. Recent developments in computational fluid dynamics (CFD), the discrete element method (DEM), digital twin, and data-driven modeling are also discussed. Compared with traditional simplified models, modern multidimensional and hybrid approaches show improved capability in describing asymmetric furnace inner states, multiphase transport behavior, and operational parameter effects under industrial conditions. However, challenges still remain in achieving computational efficiency, parameter calibration, multiphase coupling, and real-time industrial application. Future studies are expected to focus on the integration of mechanism-based simulation and intelligent data-driven methods to improve prediction accuracy, operational adaptability, and intelligent control capability in blast furnace ironmaking. Full article

This study evaluates the life cycle assessment (LCA) of Lufenuron 50-EC pesticide adsorption from aqueous solution using oil palm shell (OPS)-derived activated carbon produced through two activation routes: physical and chemical. The assessment covers environmental impacts associated with feedstock collection, transportation, pre-processing, and post-processing stages involved in producing activated carbon for pesticide removal. The cradle-to-grave LCA technique was applied using the ELCD 3.2 Greendelta v2.18 database and processed with OpenLCA v2.4 using CML-IA baseline method to perform the quantitative life cycle impact assessment. The results for treating 1 m³ of contaminated water show that physical activation route (Route 1) generates a higher environmental burden across all evaluated impact categories compared to chemical route (Route 2). Notably, global warming potential (GWP) reached 117.62 kg CO₂ eq for Route 1 compared to 75.86 kg CO₂ eq for Route 2. This represents a 35.5% reduction with the chemical route, suggesting that the high energy demand associated with thermal process in physical activation generates more significant greenhouse gas emissions. Overall, this study helped identify critical performance points and opportunities for improvement in converting the OPS to an activated carbon transformation process and its application in pesticide contamination control. Full article

With the expansion of ammonia energy applications, long-distance liquid ammonia pipelines are expected to support large-scale cross-regional ammonia transport. In the liquid ammonia pipeline commissioning process, gaseous ammonia purging involves ammonia–nitrogen mixing and possible liquefaction, while liquid ammonia injection may induce flashing and severe local cooling, all of which can affect commissioning safety. To characterize these thermodynamic phenomena, a transient gas–liquid two-phase flow model was established and validated using OLGA 2022.1.0 software for simulating the long-distance liquid ammonia pipeline commissioning. The model adopts the cross-sectionally averaged one-dimensional approach. A volume-corrected Soave–Redlich–Kwong (SRK) equation of state for ammonia was adapted, validated, and used to generate OLGA-compatible thermodynamic property tables. The results show that, during gaseous ammonia purging, a higher flowrate shortens the displacement time by accelerating nitrogen removal, and this effect is more pronounced at higher ambient temperatures due to enhanced molecular diffusion. Along the pipeline, pressure gradually decreases from frictional resistance, with a steeper drop near the outlet caused by gas acceleration, and temperature gradually approaches ambient through heat exchange with the pipe wall and surrounding soil. A high gaseous ammonia flowrate can cause partial liquefaction, regasification, and temperature fluctuations. During liquid ammonia injection, local condensation and slight liquid accumulation occur before the liquid front arrives, and the low-temperature region moves with the liquid front. The liquid ammonia mass flowrate has the strongest influence on the injection process, as it reduces the completion time but increases the outlet temperature, outlet pressure, and the low-temperature risk downstream of the valve. Therefore, it should be controlled within an appropriate range to balance efficiency and low-temperature safety risks. This work provides a rapid and efficient prediction model for key thermo-hydraulic parameters during liquid ammonia pipeline commissioning, and the overall analyses offer insights for on-site process design and safety control. Full article

Life Cycle Sustainability Assessment (LCSA) has been widely used to assess the environmental, economic, and social impacts of emerging technologies. However, its practical application in decision support remains limited due to incompatibility of units of measurement among sustainability dimensions and a lack of transparent integration mechanisms. This study constructs a monetized LCSA framework to examine how battery electric vehicles (BEVs) replacing gas-powered vehicles (GVs) in cold regions covered by carbon-intensive power systems affects overall sustainability performance. The results show that over a 15-year lifespan, BEVs reduce life cycle costs by 28.74% and carbon-related environmental costs by 25.27% compared to GVs, demonstrating significant economic and environmental advantages. However, BEVs show a 4.23% decrease in standardized socially perceived performance, primarily due to consumer concerns about transparency, privacy, and end-of-life liability. These findings suggest that incorporating social dimensions can significantly alter sustainability conclusions and reveal trade-offs that traditional single-dimensional assessments cannot capture. This study provides new empirical evidence for the comprehensive application of monetized life cycle sustainability assessment and offers valuable insights for vehicle design improvements, increased social acceptance, and low-carbon transportation policies in cold and carbon-intensive regions. Full article

The increasing concentration of atmospheric CO₂ has intensified the urgent need for efficient and sustainable carbon capture technologies. Covalent organic frameworks (COFs) have emerged as a highly promising class of porous crystalline materials for CO₂ adsorption and separation owing to their structural tunability, high surface area, and precisely designable pore environments. This review summarizes recent advances in COF-based CO₂ capture systems, covering pristine COFs, functionalized frameworks, composite materials, and membrane-based architectures. In pristine COFs, CO₂ adsorption is mainly governed by micropore confinement and physisorption within well-defined channels, where surface area and pore size distribution play key roles. Functionalized COFs introduce additional active sites, including amine groups, heteroatoms, ionic functionalities, and alkali metal centers, which significantly enhance CO₂ affinity through stronger electrostatic and acid–base interactions, often leading to mixed physisorption–chemisorption behavior. Composite COFs and mixed-matrix membranes further improve performance through synergistic effects, interfacial engineering, and enhanced mass transport. Despite these advantages, challenges remain in achieving an optimal balance between capacity, selectivity, and regenerability under realistic conditions such as humidity, low CO₂ partial pressure, and multicomponent gas streams. Issues related to scalable synthesis, structural stability, and processability also limit practical applications. Overall, this review highlights key structure–property relationships and outlines future directions, including humid-stable COFs, direct air capture, computational design strategies, and advanced membrane technologies, for next-generation CO₂ capture materials. Full article

The adoption of exhaust gas cleaning systems (scrubbers) in maritime transport generates a complex metal-laden washwater that may pose a noteworthy threat to marine ecosystems. This study assessed the acute toxic effects (LC₅₀, 48 h) of four prevalent metals detected in scrubber washwater—vanadium (V), iron (Fe), nickel (Ni), and zinc (Zn)—both individually and as a realistic mixture. For this purpose, multiple life stages of Artemia franciscana (nauplii, juveniles, and adults) and the rotifer Brachionus plicatilis have been tested under laboratory conditions. All metals induced concentration-dependent toxicity, but sensitivities varied through life stages and species tested. The sensitivity to contaminants generally decreased as the organism’s developmental stage progressed. Consequently, three different orders of toxicity can be detected. The order of metal toxicity (from highest to lowest toxicity, based on 48 h LC₅₀ values) was V > Fe > Ni > Zn for nauplii; V > Zn > Fe > Ni for juveniles and adults; and Fe > V > Zn > Ni for B. plicatilis. The Cumulative Toxic Unit (CTU) approach was utilized to compare the predicted additive effect with observed mixture toxicity. This analysis revealed a complex, life stage-dependent interaction; while antagonism dominated in nauplii (suggesting chemical mitigation), juveniles and adults of A. franciscana and the rotifer (B. plicatilis) exhibited significant synergism, amplifying the total toxicity beyond prediction. This study demonstrates that early life stages and small zooplankton are the most sensitive bioindicators of scrubber-related metal contamination, highlighting the potential ecological risk posed by metal-rich, acidic scrubber discharges that may enhance metal bioavailability and toxicity in marine environments. Full article

This Communication reports limited engineering screening data on polymer liner candidates for flexible composite pipes used in oil and gas service. Three exposure conditions were considered: hydrothermal aging in superheated water, thermal-oxidative aging in dry air, and hydrocarbon-medium exposure. Superheated-water immersion for up to 1000 h, dry-air aging for 168 h, and 7-day hydrocarbon exposure were used to describe changes in tensile properties, Shore hardness, mass, and thickness. Complete replicate records were available only for the thermal-oxidative aging dataset; therefore, most hydrothermal and hydrocarbon-medium results are reported as descriptive summary data. In the recorded data, EPDM formulation CL-2-1 retained approximately 89% of its tensile strength after 1000 h in superheated water. Sample L showed a smaller mean tensile-strength decrease than Sample Z after 168 h at 150 °C in dry air. In the hydrocarbon-medium summary data, XL95A/05B-S1 showed lower mass increase and smaller tensile-strength and yield-stress decreases than PERT XRT70H across the tested temperature range. The Communication provides case-specific screening evidence and identifies the need for replicated testing, statistical analysis, longer aging series, and structural characterization before general material-selection or durability conclusions are made. Full article

The construction sector contributes substantially to global greenhouse gas emissions, making material substitutions a key strategy for advancing sustainability transitions. Mass timber has emerged as a low-carbon alternative to mineral-based construction materials, offering biogenic carbon storage and compatibility with prefabricated and industrialized building systems. This study aims to systematically synthesize the economic, cost, and market evidence on mass timber construction by reviewing 143 peer-reviewed publications, with the objective of clarifying what is empirically known and where uncertainties remain. The reviewed literature reveals three core findings. First, economic outcomes are mixed: while several studies report regional value creation, supply-chain upgrading, and alignment with circular-economy principles, others highlight persistent constraints such as limited manufacturing capacity and uneven policy support. Second, construction cost findings vary substantially, ranging from cost parity or modest savings relative to conventional systems to premiums of approximately 10–15%, shaped by regional pricing, labor availability, transportation distance, regulatory conditions, and supply-chain maturity. Third, market-oriented studies consistently identify slow diffusion, limited practitioner experience, and risk-averse investment environments as key barriers to adoption. Overall, the review shows that economic performance is not yet consistently established and underscores the need for more standardized, context-sensitive, and methodologically consistent evaluation frameworks to support informed decision-making and the sustainable scaling of mass timber construction. Full article

To investigate the non-uniform gas–solid flow and insufficient particle residence time in an Ende pressurized pulverized-coal gasifier (EPCG), a three-dimensional cold-state numerical model of a 45,000 Nm³/h industrial-scale gasifier was established to study the effects of nozzle deflection angles (30–50°) and nozzle inclination angles (15–23°) on gas–solid flow characteristics. (1) Considering the difficulty of directly measuring particle flow behavior inside a pressurized gasifier, industrial-scale cold-state simulations were conducted to analyze particle transport and flow evolution under different nozzle structures; (2) flow uniformity and stability were comprehensively evaluated using axial velocity, particle volume fraction, residence time, and radial symmetry, and the different effects of nozzle deflection angle and nozzle inclination angle were comparatively analyzed. The results show that a typical wall-attached upward flow and central recirculation structure is formed in the bed, with particles exhibiting spiral upward transport. Flow uniformity gradually improves with increasing bed height. Increasing the nozzle deflection angle mainly enhances particle transport, whereas the nozzle inclination angle has a more significant effect on flow symmetry and stability. Nozzle inclination angles of 19–21° and nozzle deflection angles of 40–45° are more favorable for stable flow formation, while the 40°/19° configuration gives the best flow uniformity and stability. Full article

The excessive emission of greenhouse gases (CO₂, CH₄, SF₆, and CF₄.) is a primary driver of global climate change, making the development of efficient adsorption and separation technologies critically important for achieving carbon reduction goals. Metal–organic frameworks (MOFs) have attracted considerable attention in this field due to their crystalline porous structures, ultrahigh surface areas, and tunable pore architectures. However, pristine MOFs face significant bottlenecks including poor water stability, high bed pressure drops caused by their powdered form, and limited mass transfer, which severely hinder their industrial application. The integration of MOFs with functional materials such as carbon materials, polymers, metal oxides, and porous SiO₂ offers a synergistic strategy to overcome these limitations. Carbon materials provide hydrophobic barriers and mesoporous transport channels, polymers enhance processability and mechanical strength, metal oxides introduce basic sites for enhanced chemisorption, and MOF-on-MOF heterostructures enable atomic-level interfacial integration and pore synergy. This review systematically summarizes recent advances in MOF composites for the separation of CO₂, CH₄, and fluorinated greenhouse gases (SF₆, CF₄.), with an emphasis on design strategies, structure–performance relationships, and synergistic mechanisms across different composite types. Finally, the current challenges including scalable synthesis, long-term stability, and separation performance under realistic conditions are discussed, and future directions toward rational design and functional synergy for industrial carbon capture and fluorinated gas emission reduction are envisioned. Full article

Focused-ion-beam scanning electron microscopy (FIB-SEM) provides site-specific access to buried interfaces, particle interiors, porous electrode architectures, and localized degradation regions in energy materials. This capability is particularly valuable for rechargeable batteries, solid-state ion conductors, alkali-metal electrodes, and reactive solid–liquid interfaces, where the structures governing transport and failure are rarely exposed at a free surface. However, the preparation and imaging steps that reveal these regions may also alter them. Ion milling, environmental transfer, vacuum exposure, scanning electron microscopy (SEM), cryogenic handling, transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), energy-dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS), and atom probe tomography (APT) can each modify local morphology, chemistry, or phase state. These effects are especially important when the intended evidence involves light elements, metastable phases, nanoscale coatings, reactive interphases, volatile species, or ion-conducting materials. This perspective develops a claim-specific framework for evaluating such results. Preparation- and imaging-induced changes are related to the material feature being interpreted and to the minimum control needed to distinguish the two origins. For porous electrodes, the relevant outputs include pore volume, connectivity, tortuosity, crack geometry, phase fraction, and active surface area. For reactive interfaces and solid electrolytes, the critical questions concern alkali-metal redistribution, surface amorphization, light-element contrast, implanted-species chemistry, and beam-induced phase formation. The discussion further compares conventional Ga-FIB, cryogenic FIB, Xe plasma FIB, low-energy Ar+ polishing, broad-ion-beam preparation, ultramicrotomy, and repeated particle-oriented FIB workflows. Reliable interpretation requires the preparation route, transfer conditions, imaging dose, analytical acquisition, and claim-specific controls to be reported together with the final microscopy result. Full article

Under the national context of energy transition and energy conservation, accurate prediction of thermal load in oil and gas gathering and transportation stations is crucial for ensuring operational safety and reducing energy consumption. To address the limitations of traditional forecasting methods in handling the nonlinear, non-stationary, and long-term temporal dependencies of thermal load data, this paper proposes a hybrid deep learning model that integrates convolutional neural networks (CNNs), long short-term memory (LSTM) networks, and an attention mechanism, namely the CNN–LSTM–Attention model. First, key influencing factors such as ambient temperature, return water temperature, and the previous hour’s thermal load were selected as model inputs through correlation analysis. Subsequently, a CNN was employed to extract spatial features from multi-source data, LSTM to capture temporal dependencies, and an attention mechanism to dynamically focus on critical operational nodes, thereby enhancing the model’s ability to perceive important features. The experimental results show that the proposed model performs excellently in heat load prediction, achieving a root mean square error of 5.98, a mean absolute error of 4.66, and a mean absolute percentage error of 9.66%, with an R-squared (R²) value of 0.9568. Its prediction accuracy and stability are significantly superior to those of the standalone CNN and standalone LSTM models. This study provides an effective algorithmic solution for precise thermal load forecasting in oil and gas gathering and transportation stations and offers insights for optimizing the applicability of deep learning models in industrial scenarios. Full article

Membrane separation is an efficient approach for volatile organic compound (VOC) recovery from industrial off-gases due to its low energy consumption, compact design, and operational simplicity. Membrane-based VOC recovery critically depends on the membrane material, which must exhibit high VOC permeability and selectivity under mixed-gas conditions. In this study, novel highly selective membranes for VOC removal based on polydecylmethylsiloxane (PAMS-10) were synthesized using both polydimethylsiloxane and various α,ω-dienes as cross-linkers: 1,7-octadiene (OD), 1,9-decadiene (DD), and 1,11-dodecadiene (DdD). The influence of cross-linker concentration and length on mechanical, structural, sorption, and transport properties was examined extensively. The combination of three independent experimental methods (time-lag, vapor permeation, and in situ spectroscopic ellipsometry) revealed that increasing α,ω-diene concentration and decreasing its length led to a reduction in the diffusivity and permeability of permanent gases, gaseous hydrocarbons, and VOC vapors. For VOC/N₂ separation, the slightly cross-linked OD-1 membrane and the DdD-5 membrane, cross-linked with long 1,11-dodecadiene, demonstrated outstanding mixed-gas selectivities of 950/921/314/840 and 940/1084/233/1106 for toluene/n-octane/i-octane/n-butyl acetate, respectively. Notably, the DD-5 membrane, cross-linked with 1,9-decadiene, matching the length of the PAMS-10 side chain substituent, exhibited the best mechanical properties and mixed-gas selectivity comparable to the ideal selectivity, a unique behavior attributed to optimal supramolecular organization. Full article

Natural gas transportation and distribution networks are becoming increasingly heterogeneous due to the injection of biomethane, regasified LNG, and hydrogen-enriched natural gas, requiring distributed and continuous gas-quality monitoring. This work presents an industrial Raman-based instrument for in-line measurement of natural gas and hydrogen-enriched natural gas composition and related thermodynamic properties. The system employs a 450 nm broadband laser diode, a high-throughput custom spectrometer, and a pressure-rated gas cell integrated in an ATEX-certified enclosure. Gas composition is retrieved through calibration spectra and non-linear least-squares fitting, while higher heating value is calculated according to ISO 6976. The instrument was validated over pressures from 1.5 to 17 bara and temperatures from −20 °C to 55 °C using certified representative gas mixtures. The system achieved compliance with OIML R 140 Class A requirements, with HHV errors below ±0.5% and repeatability within 0.1%, while operating without carrier gases or sample manipulation. Long-term field operations in pressure-reduction stations confirmed stable performance over twelve months. The results demonstrate that Raman spectroscopy can provide a robust, low-maintenance solution for continuous natural-gas-quality monitoring and controlled hydrogen-blending applications. Full article

Gas blending with hydrogen represents a core research direction for present and future energy transport systems. The throttling of natural gas and hydrogen mixtures through pressure-regulating valves inevitably induces thermodynamic temperature variations. Theoretical analyses and simulated thermal profiles demonstrate that hydrogen blending effectively counteracts the extreme expansion temperature drop post-throttling. This thermodynamic shift alleviates the localized microclimatic thermal conditions favorable to ice-plugging, validating the feasibility of hydrogen injection as a systematic thermal mitigation strategy for high-pressure pipeline networks. This study utilizes computational fluid dynamics software to model the flow field variations in pure hydrogen and gas–hydrogen mixtures under the influence of pressure-regulating valves. Employing a real gas equation of state across varying operational temperatures and pressure conditions, this research calculates and analyzes the flow field variations driven by the Joule–Thomson effect for pure hydrogen and mixtures with varying hydrogen blending ratios. The objective is to inform temperature regulation strategies for long-distance hydrogen–natural gas pipeline networks and to establish an empirical temperature fitting relationship for pure hydrogen. The numerical evaluation indicates a maximum relative error of 6.02% and a maximum absolute error of 0.06877 K. Furthermore, guided by the localized temperature variation patterns, the temperature rise results from 75 pure hydrogen simulation cases were extracted. A Multilayer Perceptron artificial intelligence algorithm was utilized to perform inverse calculation iterations on the thermal data and regulation results. Through the stochastic selection of initial parameters and repeated training iterations referencing the fitting formula, an optimized regulation sequence was obtained. This process drives the fluid temperature to approach the practical regulation target. Following the network training phase, the maximum absolute error between the calculated temperature regulation result and the target regulation temperature is recorded at 0.0556 K, providing a methodological reference for subsequent high-pressure hydrogen applications. Full article