With the increasing global energy crisis and environmental pollution, water electrolysis for hydrogen production has attracted much attention as a clean and efficient hydrogen production technology. However, the traditional oxygen evolution reaction (OER) at the anode faces challenges such as slow reaction kinetics, high energy loss, and the generation of low-value oxygen. Recent studies have shown that utilizing reactive oxygen species (ROS) (*OOH, *OH, *O, etc.) generated during electrolysis for selective organic oxidation can improve energy efficiency, reduce costs, and produce valuable chemicals along with hydrogen. The electrode surface plays a key role in controlling the efficiency and selectivity of this process. Factors such as electrode material structure and its interaction with organic molecules strongly influence the reaction. This review discusses strategies to modify electrode surfaces for improving organic oxidation driven by ROS during water electrolysis. Three main aspects are emphasized: improving the interaction between the electrode and organic molecules, controlling charge and mass transfer, and adjusting reaction pathways through electrode design. Modification methods such as doping and strain engineering modulate the electronic properties of electrodes, thereby enhancing ROS generation and organic adsorption, which improves reaction selectivity and efficiency. In addition, electrochemical techniques like constant potential and stepped potential control can adjust metal oxidation states and electron transfer, further optimizing reaction performance. Introducing mediators or additives, using bifunctional catalysts, and applying surface intercalation strategies can also help regulate ROS behavior on the electrode surface and tune organic molecule adsorption. Future efforts should prioritize atomic-level control of electrode surfaces and mechanistic exploration of interfacial dynamics, which are critical for scalable coupling of hydrogen production with organic electrosynthesis. Cross-disciplinary integration of operand characterization and machine learning will accelerate the inverse design of catalysts with tailored ROS-substrate adsorption, ultimately bridging fundamental discoveries to sustainable chemical manufacturing.

Gas-liquid-solid fluidized bed has broad industrial application in chemical and other process industries. However, due to the complexity of the flow (with characteristics of multi-scale, non-stationary, nonlinear, etc.) and the limitations of multi-phase flow measuring techniques and mechanism models, it is still difficult to scientifically design it. At this time, numerical simulations based on computational fluid dynamics have become an effective way to quantitatively describe three-phase flow. The numerical simulation methods for three-phase flow are generally divided into modeling and direct numerical simulation. Among them, direct numerical simulation is to analyze the interaction between bubbles, particles and fluids at the microscopic scale without introducing drag models, which can reveal the interaction mechanisms between gas, liquid and solid phases and is a method that focuses on. The commonly used direct numerical simulation methods for multi-phase flow, such as volume of fluid, level-set, front tracking, immersed boundary, distributed lagrange multiplier/fictitious-domain, lattice Boltzmann and smoothed particle hydrodynamics are outlined, and the advantages and disadvantages of various simulation methods are compared. Afterwards, the research progress on direct numerical simulation of three-phase flow is reviewed. Finally, the existing problems in direct numerical simulation and future research directions are pointed out.

Chemical biomanufacturing process has the advantages of green, low-carbon, environmentally friendly and sustainable, and its role in the chemical industry is becoming increasingly important. However, the biosynthesis monitoring, control and optimization as well as the separation of products during the biomanufacturing processes always have real-time dynamic complexity due to the influences of metabolicregulation and external environmental factors. The complex nonlinear relationships in data from these dynamic processes can be obtained by machine learning methodology without the need for explicit understanding of process mechanisms, which could then be helpful to reveal the bioprocess laws, and thus improve the optimization and prediction of biomanufacturing processes. In this paper, recent advances regarding the machine learning methodology, key algorithms and typical applications in the optimization, monitoring and control of biosynthesis processes, the development of bioseparation processes, and the production of biofuel chemicals, were summarized and analyzed. The challenges to be addressed in further applications of machine learning in the manufacturing process of chemicals were also discussed.

Under the dual challenges of global climate change and energy structure transformation, the development of efficient and clean hydrogen storage and transportation technology has become a key path to achieve the goal of carbon neutrality. Liquid organic hydrogen carriers (LOHCs) technology has become a research hotspot in the field of hydrogen energy storage and transportation due to its high safety and the ability to utilize existing infrastructure. However, the slow dehydrogenation kinetics and strong catalyst dependence limit the industrialization process. In recent years, breakthroughs in machine learning (ML) in new material design, reaction optimization, and data-driven modeling have injected new momentum into LOHCs technology. This paper focuses on the latest research of ML in aspects such as the molecular screening of LOHCs, catalyst design, and reaction condition optimization, points out the current research shortcomings, and prospects the future development directions.

Although the solid-state metal secondary battery has high energy density and good safety, there are still some problems such as low ionic conductivity of solid electrolyte, poor interface contact between electrode and solid electrolyte, and dendrite growth from the metal anode, which seriously hinder its application prospect in large-scale energy storage. Piezoelectric materials can realize the mutual conversion between mechanical energy and electrical energy, possessing the characteristics of generating internal electric field by polarization. They can be used to suppress the space charge layer, promote ion transport dynamics, and regulate the uniform deposition of metals in solid-state batteries. This paper first introduces the basic concepts, classifications and working principles of piezoelectric materials, and then reviews in detail the research status of piezoelectric materials in solid-state metal secondary batteries in recent years. Finally, the main problems and future development prospects of piezoelectric materials applied in solid-state batteries are summarized.

The transport properties of NdF₃-LiF molten salt, such as electrical conductivity and viscosity, significantly impact the electrolytic preparation process of rare earth metal neodymium and the technical economic indicators such as energy consumption in electrolytic production. In this study, molecular dynamics simulations (at 1323 K) were employed to investigate the effect of NdF₃ content on the local structure and transport properties of NdF₃-LiF molten salt. The results indicated that as the content of NdF₃ increased, [NdF₉]^6- and [NdF₈]^5- transformed into [NdF₇]^4- and [NdF₆]^3-. The proportions of bridge fluorine and end fluorine in the fluorine ion connection type increases, among which the proportion of bridge fluorine increases more. In the connection modes of [NdF₈]^5- polyhedrons, the proportion of common vertices decreases, and the proportion of common edges and common faces increases. The order of ion diffusion ability was: Li⁺> F^-> Nd³⁺. As the molar content of NdF₃ increased from 20% to 55%, the viscosity of the molten salt increased from 3.31 mPa·s to 7.43 mPa·s, and the electrical conductivity decreased from 4.84 S·cm^-1 to 1.78 S·cm^-1. This study clarified the transport properties of NdF₃-LiF molten salt and revealed the fundamental reasons for their changes, providing scientific guidance for the low-carbon, green, and efficient preparation of rare earth metal neodymium.

To further grasp the characteristics and patterns of two-phase flow and boiling heat transfer during the precooling process of low-temperature pipelines, a coupled heat flux numerical model was developed for the precooling process of low-temperature pipelines, focusing on liquid nitrogen transfer pipelines. Utilizing the one-dimensional drift flow model, particular emphasis was placed on the influence of gas-liquid interphase slip velocity. The variations in pipe wall temperature, gas content, heat flux density, and gas-liquid interphase slip velocity during the precooling process were computed. Comparative analysis was conducted on the fluctuations of average velocity and mass flow rate at various times, pipeline positions, and lengths. The findings indicate that the drift flow model offers a more precise prediction of the two-phase flow and heat transfer characteristics during the precooling process, achieving a 3.9% reduction in error compared to the homogeneous flow model. The majority of the precooling process occurs within the two-phase flow regime, where the slip velocity between gas and liquid phases cannot be disregarded. Furthermore, an increase in gas content leads to a greater deviation in the average gas phase slip velocity compared to the homogeneous flow model. Significant fluctuations were observed in both average velocity and mass flow rate during the precooling process. For a 0.572 m long pipeline, the average velocity fluctuation amplitude neared 1.5 m/s, while the maximum amplitude of the average mass flow rate fluctuation is close to 45 kg/(m²·s). The length of the pipeline significantly impacts mass flow rate fluctuations, with longer pipelines experiencing greater average mass flow rate fluctuations. Within the same pipeline, the fluctuation amplitude of mass flow rate is more pronounced at downstream positions compared to upstream. The research results of this paper are of great significance for the in-depth understanding and optimization of the precooling process of cryogenic pipelines.

Ultrafine powders play a crucial role in promoting technological development and improving product performance in various industries. However, due to their small particle size, large specific surface area, and strong inter-particle forces, ultrafine powders often exhibit poor flowability, creating challenges for mass-flow hopper design. This paper uses two kinds of ultrafine powders as experimental materials, and uses the PT-X powder comprehensive property tester and FT4 powder rheometer to characterize the powder fluidity through the angle of repose method, Hausner ratio (HR) method, shear test method, etc. Furthermore, by conducting experiments of aerated discharge, the effects of aeration, hopper outlet diameter, and powder properties on flow behavior of ultrafine powders were studied. Finally, based on the Jenike theory, the stress evolution and hopper design of ultrafine powder under aeration were investigated, and the critical flow equation for powder in the aerated hopper was established, yielding the functional relationship between the critical hopper outlet diameter and aeration volume/superficial velocity of mass-flow hoppers. The proposed aeration-coupled design method provides both theoretical foundations and practical guidelines for optimizing ultrafine powder hoppers.

The flow boiling heat transfer characteristics of zeotropic mixtures in mini-channels are investigated using a numerical approach based on the volume of fluid (VOF) multiphase model, incorporating an improved Lee phase change model. The model's accuracy is validated through comparison with experimental data. Under constant wall temperature conditions, the effects of mass flux [50—1100 kg/(m²·s)], mixture composition (R134a inlet mass fraction 0.1—0.9), and wall temperature (32—70℃) on heat transfer performance are systematically analyzed. The results indicate that at low mass flux, an increase from 50 kg/(m²·s) to 400 kg/(m²·s) enhances the heat transfer coefficient by more than 90%. However, at high mass flux, further increasing to 1100 kg/(m²·s) reduces the heat transfer coefficient by approximately 27%, suggesting a transition in the dominant heat transfer mechanism. At the same time, when the inlet concentration of the low-boiling component R134a increases from 0.1 to 0.3, the heat transfer coefficient decreases by 15% to 45%. Furthermore, at high R134a concentrations, the heat transfer coefficient rises significantly as wall temperature increases from 32℃ to 40℃, after which it stabilizes, reaching a peak near 40℃. These findings provide insights into the underlying transport mechanisms governing zeotropic mixture flow boiling in mini-channels and offer guidance for optimizing thermal management applications.

Three-phase fluidized bed reactor is characterized by a complex, non-uniform, and dynamic structure. To gain a deeper understanding of the influence of internal component design parameters on the performance of three-phase reactors, this study employs the Eulerian-Eulerian multi-fluid model in conjunction with the open-source software OpenFOAM to conduct numerical simulations of internal components within a gas-liquid-solid fluidized bed. The investigation focuses on the effects of three different porosities (0.866, 0.219, 0.072) of spargers and two distinct baffle heights (20 m, 6.8 m) on the flow behavior of particles and gas. The results show that the total bubble volume density of the three types of distributors with three opening ratios is the highest when the opening ratio is 0.219, which is 12.4% and 22.6% higher than that of the total opening ratios of 0.866 and 0.072, respectively. Reducing the baffle height from 20 m to 6.8 m led to an increased bubble count in the upper bed layers, resulting in a 13.4% increase in the total bubble number in the fully developed section.

In order to improve the uniformity of gas-liquid two-phase distribution in alkaline electrolyzers and improve the efficiency of hydrogen production, considering the coupling effect of electrochemistry and gas-liquid two-phase flow, a three-dimensional numerical model of the electrolyzer was established. The study shows that the interaction between the gas and liquid phases causes big differences between the real flow state and the ideal single-phase flow state in the electrolyzer. The difference between the average flow rate of the electrolyte in the simulated flow channel by the two models is more than 20%. Additionally, the effects of the structural parameters of the elliptical mastoid on electrolyzer performance were investigated. As major axis length of the mastoid increases, the area of the low-speed vortex region formed downstream of the mastoid first increases and then decreases. Compared to the circular mastoid, the elliptical mastoid improves the gas-phase distribution uniformity on the electrode surface by 12.28% and increases hydrogen production by 142.77%.

The curved-tee in the pneumatic conveying system of a petrochemical enterprise is composed of a tee and a 45° elbow. It had leakage failure problems many times during operation. The CFD-DPM numerical simulation method was used to study the erosion law of the curved-tee and to analyze the influence of the flow field on the particle trajectory, which resulted in the erosion behavior of the particles on the target material. The results show that there is a coupling between the influence of tee and elbow on the particle trajectory. The severe erosion zone is mainly distributed in the front wall of the elbow and has a distinctive curved feature. The branch gas has a “gathering” effect on the particles, which aggravates the erosion damage of the curved-tee. Finally, it is suggested that significant erosion relief can be achieved by moving the branch pipe downwards or using a small angle elbow.

Steam condensation exhibits high heat transfer efficiency and is playing a crucial role in applications such as power and electric generation, aerospace engineering, nuclear engineering, air-conditioning, etc. This paper reports experimental investigations of condensation droplet shedding performances on star-shaped hydrophobic-hydrophilic hybrid surfaces. Testing surfaces are designed and fabricated first, then the experimental system and procedures are introduced. Visualization studies are carried out on the droplet shedding characteristics of three types of hybrid surface, i.e. four-star, five-star and six-star hydrophilic region designs. The droplet shedding diameter, initial droplet shedding time and droplet shedding frequency of the combined surface and the pure hydrophobic surface were compared and analyzed, and the residual condensate area and its distribution characteristics of the droplet shedding hydrophilic region of the combined surface were calculated and statistically analyzed. The results reveal that hybrid surfaces enable high-frequency droplet shedding with large droplet size compared with hydrophobic surfaces, which means higher condensate refreshing rate and enhanced condensation heat transfer performance.

A new gas dispersion method of electric field dispersion technology coupled with tubular packed bed was proposed, and an electric disperser coupled tubular packed bed experimental device was built. Using a biodiesel-nitrogen upward flow system and high-speed imaging, the bubble dispersion process was visualized to investigate the dispersion mechanism of charged bubbles and the dispersion characteristics of bubble groups under a non-uniform electric field. The results indicate that under the influence of the electric field force, bubbles accelerate detachment and disperse into multiple uniformly sized charged bubbles. As the characteristic electric field strength increases, the Sauter mean diameter of the bubble group decreases from 1.80 mm to 650 μm, forming a narrow Gaussian distribution. Based on these findings, the electric disperser was further coupled with the tubular packed bed to examine the effects of characteristic electric field strength, gas flow rate at the orifice, liquid flow rate, and packing type on the secondary dispersion of charged bubble groups before and after passing through the packed bed. The results demonstrate that the initial dispersion by the electric disperser and the secondary dispersion within the packed bed exhibit strong synergy. The number of bubbles per unit volume in the packed bed outlet region remains stable between 4.0×10⁷ and 8.0×10⁷, with the Sauter mean diameter of the bubble group stabilizing between 600—700 μm. Moreover, the electric disperser-coupled tubular packed bed exhibits excellent stability and adaptability under various operating conditions. Without altering the gas-liquid ratio, real-time control of charged bubbles can be achieved by adjusting the characteristic electric field strength. These findings provide a reference for the application and development of electric dispersion coupled with packed bed technology in gas-liquid two-phase reactors.

Condensation is a common phase transition process existing in nature, which is widely used in petrochemical, nuclear power generation, refrigeration and other industrial fields, and has broad application prospects. Among them, surface droplet distribution and rapid detachment of condensate are important factors affecting the droplet condensation heat transfer efficiency. An experimental system of condensation on vertical surface was designed and the influence of contact angle and surface subcooling on condensation heat transfer performance was conducted. In addition, Cellpose algorithm was utilized which based on deep learning to analyze and quantify the size and distribution laws of droplets on the condensation surface. We found that the hydrophobic surface had the best heat transfer efficiency when the contact angle was about 120°. We summarized with a focus on analyzing the effects of droplets distribution density, droplets departure radius, and growth cycle in response to this phenomenon. The difference of cleaning area per unit time and the effect on heat transfer efficiency of droplets at different contact angles was quantitatively described.

In a gas-solid two-phase flow, the particles suspended in the gas are mostly non-spherical, whose geometric shape and orientation have a significant impact on particle transport. Non-spherical particles are usually simplified as sphere particles, but this may cause serious errors. While the specific expressions for non-spherical particles are too complex to be employed for practical applications. In this paper, we derived a general expression for the thermophoretic force of non-spherical particles in the free molecular regime. Then specific expressions for the thermophoretic force on sphere and cylinder can be obtained. Considering the high-speed Brownian rotation of particles in the free molecular region, a uniformly random distribution of the particle orientation can be assumed in the case of weak potential field. Based on this, the expression of the orientation-averaged thermophoretic force on particles of any shape can be derived, which is found to be proportional to the surface area of the particles, and the proportion coefficient is independent of the particle size or shape. This result is verified by direct simulation Monte Carlo, providing a new idea for simplifying the research on particle transport characteristics and its application.

The screw extrusion process of solid propellant has the advantages of continuous process flow, stable product quality and strong self-control. The propellant grain produced is suitable for large-scale promotion and application. To fully enhance the combustion efficiency of screw-extruded propellants, this paper focuses on four complex grain geometries with equal arc thickness. Different screw extrusion die structures were designed, and the screw extrusion process of solid propellants was simulated based on numerical simulation methods. The flow characteristics and extrusion swelling phenomena of the propellant material during the extrusion process with different die structures were analyzed. The simulation results were compared with experimental data to explore the main factors influencing the precision extrusion quality of complex grain geometries. The results indicate that the flow state of the propellant material at the die outlet is largely determined by the pressure-building capability of the screw. Different die structures can improve the non-uniform flow of the material within the cross-section. By analyzing the flow balance coefficient during the screw extrusion process, it was found that the die structure matching the wheel-type grain geometry resulted in the smallest flow balance coefficient at the material outlet, with the flow velocity in the low-speed region being approximately 42%—56% of the maximum velocity. Additionally, the extrusion swelling ratio was relatively small at 1.095, indicating optimal grain formation quality.

Aiming at investigation of the agglomeration process and characteristics of fine particles in the flue gas under the effect of an acoustic field, a stochastic model that describes the agglomeration of fine particles in a plane standing wave acoustic field was established using a direct simulation Monte Carlo method. The modelling was based on the dynamical processes, including the particle motion and interaction induced by the acoustic field, the collision between particles, and the consequent agglomeration or rebound upon particle collision. The model comprehensively considers the interaction mechanisms between particles, such as orthokinetic interaction, gravity sedimentation, acoustic wake effect, mutual radiation pressure effect, and Brownian diffusion. The particle collision is regarded as a random event, and the occurrence of collision is judged by a random algorithm. The acoustic agglomeration processes of fine particles in flue gas were numerically simulated using the presented stochastic model. Based on the model validation by comparison with experimental data, the evolution of the particle parameters over time was demonstrated, and the effects of flue gas temperature and pressure on the performance of acoustic agglomeration were discussed. The results indicate that as the acoustic agglomeration progresses, the particle number concentration peak drops, the total particle number concentration reduces, and the computed particles demonstrate a tendency of increasing in size and decreasing in number weight. As the flue gas temperature increases from 315 K to 1015 K, the acoustic agglomeration performance significantly enhances initially, whereas when the flue gas temperature is higher than 415 K, the sensitivity of acoustic agglomeration performance to the temperature weakens. The acoustic agglomeration effect diminishes monotonically as flue gas pressure rises when the acoustic field intensity remains constant. Particularly, when the pressure raises up to 1 MPa, the acoustic agglomeration effect becomes rather weak.

In order to reveal the enhancement effect of the hydrophilic-hydrophobic composite structure surface on condensation heat transfer and the effects of dynamic behavior characteristics of condensate droplets, an experimental system and a mathematical model of condensation on the hydrophilic-hydrophobic composite surface was established. The model is based on the theories of dropwise condensation (DWC) and filmwise condensation (FWC), in combination with the effects of droplets nucleation, merge, detachment, and sliding sweeping. The effects of surface structure size, wettability, operating temperature and droplet dynamic behavior on condensation efficiency were analyzed by the model. The diameter of the circular hydrophobic area on the composite surface is W_DWC, and the interval of the hydrophilic channel is W_FWC. The results show that under different conditions, the condensation coefficient increases first and then decreases with the increase of W_DWC. There is a unique W_DWC corresponding to W_FWC, which makes the condensation coefficient reach the highest. Moreover, the optimal W_DWC is only affected by W_FWC and is insensitive to other factors. The average condensation heat transfer coefficient of the optimal structure size(W_DWC=1.5 mm,W_FWC=0.5 mm) can be increased by 71.4% compared with that of the completely hydrophobic surface at a contact angle of 110°, a steam temperature of 70℃ and a subcooling of 5℃.

This study investigates the rebound dynamics during the collision between mist droplets and particulate matter, aiming to provide theoretical guidance for particle settlement in water mist technology applications. We focused on particles ranging from 1 μm to 125 μm and used numerical simulations to analyze their rebound behavior when colliding with droplets of similar diameters. Scatter plots of collision behavior were analyzed to obtain a fitting curve for the critical rebound condition, and a physical model was constructed. The model developed in this study involves more dependent variable parameters than previous predictive equations for critical rebound conditions, comprehensively revealing the multiple factors influencing rebound behavior. The research indicates that rebound phenomena mainly occur when droplets collide with hydrophobic particles at low speeds. Smaller droplet sizes result in higher critical rebound velocities, explaining why smaller particles are more difficult to settle through water mist in dust suppression practices. Reducing the dust-mist contact angle can effectively inhibit the rebound, and the rebound phenomenon disappears when the contact angle is less than 90°. The research findings can quantitatively predict the occurrence of a rebound during a dust-mist collision, thereby guiding the optimization of water mist operating parameters in the practice of dust settlement and ultimately promoting significant improvements in dust removal efficiency. This study provides a comprehensive understanding of the rebound dynamics and offers practical guidance for enhancing the effectiveness of water mist technology in dust control applications.

Based on the principle that phase change frosting is essentially heat and mass transfer, this study further considered the practical phenomena where the gradual reduction in frost layer porosity and the increase in thermal resistance leads to decreased water vapor diffusion capacity and heat transfer efficiency. To address these effects, the study introduced the concepts of effective diffusion coefficient (D_eff) and the equivalent heat transfer coefficient (h_eq). Additionally, the calculation formulas for the mass transfer factor (j_m) and heat transfer factor (j_h) were revised, and the dimensionless parameter J(j_m/j_h) was coupled into the quasi-steady frost formation model, leading to a reasonable correction of frost layer characteristic parameters. To verify the prediction accuracy of the improved model, comparisons were made between this model, the Lee model, the Lenic model, and the Wong model, as well as with 38 measured data sets from seven representative experimental conditions. The results show that the prediction accuracy of the improved model increased by 31.81%, 64.57% and 50.64%, respectively, compared to the aforementioned models. Furthermore, the predicted values of the improved model closely match the experimental data under typical conditions, with the average error of frost layer thickness below 6.57%, the average error of frost density under 7.10%, and the average errors of frost surface temperature and frost mass being 8.41% and 9.59%, respectively.

Considering the small number of channels and low cooling capacity of current microchannel throttling cryocoolers, a multi-layer, multi-channel parallel printed circuit board microchannel throttling cryocooler is designed. The channel structure of the cryocooler is a combination of microchannels with different cross-sectional sizes to achieve different functions. It is used for reheating and pre cooling in a heat exchange channel with an equivalent diameter of 0.46 mm, and distributed throttling cooling and regenerative pre cooling coupling within a throttling channel with an equivalent diameter of 0.12 mm. Analyze the refrigeration performance of the cryocooler under different inlet pressures of 2.01—8.02 MPa using Ar as the working fluid. The results show that under various operating conditions, the heat exchange of the heat recovery device is relatively sufficient, and the distributed throttling components have significant cooling ability. When the inlet pressure of Ar gas is 8.02 MPa, the lowest temperature of 158.5 K can be reached, and the temperature gradient of the pre cooling section and throttling section reaches 0.79 and 1.04 K/mm, respectively. When the inlet pressure of Ar is 6.00 MPa, the cold end temperature is 196.7 K, accompanied by a parasitic cooling capacity of 2.73 W. At a cold end temperature of 219.8 K, it has a total cooling capacity of 6.08 W, which is significantly improved compared to similarly sized throttling cryocooler. Comparing the experimental results of Ar and N₂ in microchannel throttling cryocooler, the cold end temperature that Ar can reach is always lower than that of N₂ under similar operating conditions. But at the same outlet pressure, N₂ has the potential to reach a lower limit temperature. In addition, the operating characteristics of distributed throttling are analyzed through the J-T effect. The coupling effect of heat exchange and J-T effect shows that the thermal and heat transfer processes have different rules. Compared with adiabatic throttling, the throttling process has a higher system completion degree and increased J-T efficiency, which can alleviate the heat exchange pressure of the pre-cooling mechanism before throttling.

Methyl propionate (MP), as a key organic intermediate in pharmaceutical and fragrance synthesis, currently faces production challenges including high energy consumption during separation and low production efficiency. Based on this, this study proposes a new route for continuous synthesis of MP in a fixed bed reactor using methanol and methyl acetate as raw materials under high partial pressure (60 kPa) of raw materials. A series of high-performance Ti-modified Cs/SiO₂ catalysts were developed, and their physicochemical properties were characterized using XRD, BET, TEM, XPS, CO₂/NH₃-TPD and UV-Vis spectroscopy. The results indicate that the introduction of Ti significantly modulates the acid-base properties of the catalyst, and the proportion of weak acid sites to total acid sites coupled with the ratio of weak base sites to total base sites critically governs the activity in aldol condensation reactions. In the key step of the one-step MP synthesis (aldol condensation of formaldehyde and methyl acetate), the conversion of methyl acetate exhibited a volcano-shaped trend with the loading of Ti, reaching a maximum of 29.4% at a Ti loading of 4%(mass). Correspondingly, in the tandem reaction of methanol and methyl acetate to produce MP, the catalyst demonstrated the highest catalytic activity, with an MP yield of 23.6%. This study elucidates the mechanism by which Ti modification affects the acid-base properties and reaction performance of the catalysts, providing theoretical insights and technical support for the catalyst design and process scale-up of one-step MP synthesis from methanol and methyl acetate.

It is an effective way to mitigate global warming and achieve carbon resources reuse by CO₂ hydrogenation to methanol. Cu/CeO₂ is an important catalyst for CO₂ hydrogenation to methanol, but the methanol selectivity still needs to be further improved. In this work, the xGaCuCeO catalysts with different amounts of Ga₂O₃ were prepared to modify its catalytic activities. The results show that Ga₂O₃ enhances the adsorption strength of CO₂ on the catalyst surface and increases the oxygen vacancy content on the catalyst surface, thereby improving the methanol selectivity of xGaCuCeO catalysts. Compared with the CuCeO catalyst, the 0.07GaCuCeO catalyst with Ga content of 1.1% (mass) has increased the selectivity of methanol by 47% and space-time yield by 26% (22.4 g·kg^-1·h^-1).

In order to investigate the mechanism of the preparation of calcium carbonate (CaCO₃) powders by the bubble disturbance enhanced impinging stream reactor, CaCO₃ powders with different crystal structures and contents were prepared by the impinging stream co-precipitation method. The effects of reaction temperature on the precipitation form and transformation process of CaCO₃ crystals under bubble disturbance were investigated, and the crystal phase content, nucleation rate and particle size of CaCO₃ crystals at different gas-liquid flow ratios were studied. The experimental results show that the reaction temperature is the key factor affecting the crystal morphology, and with the increase of temperature, the precipitation form of CaCO₃ crystals changes in the order of calcite, vaterite and aragonite. The bubble disturbance can effectively regulate the CaCO₃ crystal content and particle size. With the increase of gas-liquid flow ratio, the content of vaterite CaCO₃ first decreases and then increases, the nucleation rate first increases and then decreases, and the average particle size first decreases and then increases. When the gas-liquid flow ratio r=1.00, the content of vaterite in the product reaches the highest level and the average particle size is the smallest. This research provides a reference for regulating the morphology of CaCO₃ crystals in impinging stream reactor.

Low temperature catalytic hydrolysis of carbonyl sulfide (COS) is a key technology for promoting the clean conversion and utilization of gas. Modern syngas has low COS content after high temperature purification, but industrial gas sources (such as blast furnace and coke oven) have high COS content (75—400 mg·m^-3). Therefore, the study of COS hydrolysis technology is of great significance for industrial gas purification and efficient preparation of syngas in the future. Previous studies have shown that γ-Al₂O₃ loaded with rare earth metals exhibits strong catalytic hydrolysis activity under low COS concentrations, but its behavior under low temperature and high COS concentrations remains unclear. This study investigates the enhancement effects of different rare earth metal oxides (La₂O₃,Sm₂O₃ and CeO₂) on the catalytic hydrolysis behavior of γ-Al₂O₃. Based on the influence of gas composition and various structural characterizations, the interactions between the selected rare earth metals and γ-Al₂O₃ are analyzed. The results indicate that, under conditions of 70℃, 1000 mg·m^-3 COS, 3% H₂O and 0.5% O₂, the modified catalyst (Sm₂O₃/γ-Al₂O₃) with Sm₂O₃ (the mass fraction is 5%) loading shows the best performance. After 8 h of reaction, the selectivity of H₂S is 86.3%, and the COS conversion rate remains above 90%, which is higher than that of unmodified γ-Al₂O₃ (65.3%). Additionally, Sm doping enhances the resistance to H₂S poisoning, attributed to the increased basic sites on the surface of γ-Al₂O₃. The presence of CO₂ significantly weakens the effect of Sm₂O₃/γ-Al₂O₃ on COS conversion (reduced by 39.6%), which is due to the competitive adsorption of CO₂ leading to catalyst deactivation, and this process is reversible. In addition, under the coexistence of H₂S and CO₂, CO₂ preferentially adsorbs on the catalyst surface, occupies basic sites and rapidly deactivates the catalyst.

In this study, the MTW zeolite was modified by the secondary crystallization method, and its catalytic performance and mechanisms in the alkylation reaction of benzene and cyclohexene were deeply explored. The structural parameters and acid site concentration of the prepared MTW zeolite samples were systematically explored by various characterization methods such as XRD, ICP-OES, N₂ adsorption-desorption isotherm, SEM and Py-IR. At the same time, the catalytic performance of MTW zeolite samples in the alkylation of benzene and cyclohexene was evaluated by fixed bed reactor. The characterization results show that the secondary crystallization method successfully introduced mesoporous structures into the MTW zeolite. Without changing the crystal configuration, the total Brønsted acid amount and the external-surface Brønsted acid amount were significantly increased. The catalytic performance results of the alkylation reaction of benzene and cyclohexene indicate that the activity of the MTW zeolite after the secondary crystallization treatment is significantly improved. Among them, MTW-Ⅱ exhibits the most excellent conversion rate, reaching 41.74%. At the same time, the modified MTW zeolite performs outstandingly in terms of selectivity, all remaining above 75%. In addition, through a clear analysis of the components of the reaction mixture, the reaction network of the alkylation reaction of benzene and cyclohexene was successfully deduced. This study demonstrates that the secondary crystallization method is an efficient modification method for MTW zeolites, providing a solid theoretical support for the industrial production of cyclohexylbenzene and opening up a new path for the design and optimization of zeolite catalysts.

Waste plastic mineral-water bottles were converted into nitrogen-doped porous carbon materials using template carbonization and hydrothermal methods, then CoMoO₄ nanoparticles were loaded on the plastic-derived nitrogen-doped carbon (PNAC) to prepare the composite (CoMoO₄@PNAC) materials using hydrothermal and annealing methods, the latter were tested as catalysts for the electrocatalytic hydrogen evolution reaction (HER) in water electrolysis. The synthesized CoMoO₄@PNAC material exhibits good hydrogen evolution catalytic activity in 1 mol/L KOH alkaline electrolyte, requiring only 162 mV overpotential to reach a current density of 10 mA/cm², and exhibits good stability. PNAC provides an efficient electron transfer channel, and its curled nanosheet shape can perturb the electrolyte near the CoMoO₄ nanoparticles, accelerating the mass transport between the electrolyte and the active site and promoting the rapid detachment of the bubble products. DFT calculations show that CoMoO₄@PNAC has a lower ΔG_H* compared to CoMoO₄, and the DOS curves show that the introduction of PNAC fills the density-of-states gap among pure CoMoO₄, realigns the electron distribution, increases the density of states near the Fermi energy level, improves the number of available electrons, and releases the catalytic potential of CoMoO₄ towards HER, all of these leads to a high catalytic performance of CoMoO₄@PNAC.

This paper evaluates the potential of nanofiltration membrane technology for concentrating rare earth elements. Commercial nanofiltration membranes were screened in terms of rare earth ion retention and anti-fouling performance, and it was found that improving the saturated solubility of calcium sulfate is the key to improving the concentration rate. Further investigations were conducted to explore the relationship between CaSO₄ solubility and solution conditions, leading to the optimization of the nanofiltration process. Adjusting the solution pH effectively controlled CaSO₄ scaling on the membrane surface, improving membrane performance and increasing rare earth ion concentration. Additionally, the impact of membrane fouling under various operating conditions was analyzed using the Hermia model, providing a theoretical foundation for membrane cleaning and extending service life. This study offers an efficient and environmentally friendly solution for concentrating rare earth leach solutions, with significant application potential.

Hydrogen-driven electrochemical carbon capture system (HECCS) is a new method for low-concentration CO₂ capture and separation. Due to limitations such as large-area membrane preparation, membrane performance, and electrode performance, the single-module carbon capture capacity of HECCS is limited. To enhance the carbon capture performance and economic efficiency of the HECCS, a modular design and optimization approach for the HECCS is proposed. Based on analyzing the operational performance of a single HECCS module, the carbon capture strategies and optimal operation methods for the modular HECCS are established. The structural characteristics of modular HECCS systems and the coordination and matching features between modules are elucidated. The results indicate that in specific scenarios for capturing CO₂ at low concentrations, different combinations of the modules within the modular carbon capture system significantly influence the carbon capture performance and economic efficiency. Under certain operating conditions, the series structure exhibits superior decarbonization effects compared to the parallel structure, while the multi-stage structures are favorable for reducing hydrogen consumption. The optimal number of stages for an HECCS system is significantly influenced by factors such as inlet and outlet CO₂ concentration, hydrogen price, and HECCS module cost, which is a trade-off between the operating expenses and investment costs of the system. This work provides the optimal design method for enhancing the performance and economic efficiency of modular HECCS systems.

In the preparation of high-performance ternary cathode materials, the ternary precursor serves as a core raw material, and its quality—especially the particle size distribution—has a decisive impact on the physicochemical properties of the sintered cathode product. The preparation of ternary precursors involves various process parameters, among which ammonia concentration, reaction temperature, pH value during the reaction, stirring rate, and reaction time all significantly influence particle size. Among these, reaction time has the most pronounced effect on the particle size of the ternary precursor. This study proposes a dynamic prediction model for the particle size distribution during the crystallization process of ternary precursors, based on a particle population balance equation. First, considering the growth characteristics of the co-precipitation process of ternary precursors, a particle size prediction model based on the population balance equation is established, taking into account both the growth rate described by the ASL equation and a generalized growth rate expression. Secondly, the population balance equation was discretized in space and time dimensions using the collocation method, and the unknown parameters in the model were identified by constructing an optimization problem. Finally, simulation results show that the proposed prediction method can accurately simulate the particle size evolution of ternary precursors with different initial sizes during the crystallization process, achieving precise prediction of particle size distribution. This provides a solid theoretical foundation and reference for optimizing the sintering process of ternary cathode materials.

To address the impact of temperature and current inhomogeneity inside the solid oxide electrolysis cell (SOEC) stack on the system's hydrogen production efficiency, safe and stable operation, and lifetime, first, based on the geometric structure of the SOEC power reactor, a three-dimensional (3D) model coupled with multi-physics fields that can accurately analyze the charge transport process, fluid flow, material transport process and heat energy transfer process of the SOEC is established. Secondly, in order to optimize the simulation process of the model, boundary constraints are imposed on the model and its structure is meshed to obtain an adaptive incremental Kriging agent model optimization that satisfies the constraints, which confirms the accuracy of the model optimization and reduces the simulation time and the total amount of computational resources. Finally, the multi-objective optimization algorithm for the steady-state operation of SOEC reactors is proposed to increase the efficiency of electrolytic hydrogen production and improve the inhomogeneity by analyzing the characteristics and causes of the inhomogeneous distribution of temperature, material, current density and voltage inside the stacks, and through numerical simulation and experimental verification, considering the optimization method of temperature and current uniformity distribution inside the stacks, it can greatly improve the safe and stable operation and hydrogen production of the stacks.

To address the challenges of strong nonlinearity and time-varying characteristics in chemical industrial processes, this paper proposes a Newton-Raphson based optimizer (NRBO) driven stacked long short-term memory (SLSTM) network for operational state evaluation. The method enhances the expression ability of time series data by stacking multiple layers of LSTM networks and introducing the Dropout layer. At the same time, the second-order derivative optimization characteristics of the NRBO algorithm are used to effectively improve the convergence speed and classification accuracy of the model, avoiding the problem that the traditional LSTM evaluation method is prone to fall into the local optimum in the high-dimensional parameter space. In experimental validation on the Tennessee Eastman (TE) process, the proposed method achieved a prediction accuracy of 99.31%, which is significantly higher than several comparison methods. For identifying non-optimal states, a combined method based on principal component analysis and group lasso regularization contribution (PCA-GLC) is proposed. This method can effectively identify key variables, reduce misjudgments and interference, and provide accurate information for real-time adjustments in industrial processes. Experimental validation on the TE process demonstrated that the proposed method, compared to the PCA-based graph contribution method, more accurately identified key variables and reduced the interference from other variables.

There is a spatiotemporal coupling relationship between autocorrelation and mutual correlation in the monitoring variables in complex chemical processes, which leads to redundant information in the process of fault propagation path identification, resulting in incorrect path identification. Therefore, a fault propagation path backtracking method that integrates monitoring data and process knowledge is proposed. Distributed interactive monitoring is introduced based on the fault propagation path analysis of k-nearest neighbors to determine the potential fault area and eliminate redundant variables. A connectivity model based on an undirected adjacency matrix is extracted from the process to provide logical guidance for fault path backtracking. Compared with the traditional transfer entropy method and the k-nearest neighbor method, the proposed method, through the fault cases of the Tennessee Eastman process and the ammonia synthesis process, effectively improves the accuracy of fault path identification and reduces redundant paths.

The friction and wear on the end face of the dry gas seal ring, which leads to the loss of gas hydrodynamic pressure effect and an increase in leakage, is one of the common failure modes of dry gas seals. Therefore, stringent requirements are put forward for the tribological properties of the end face of dry gas seals. The “hard-on-hard” pairing method represented by silicon carbide (SiC) material is one of the mainstream pairing methods for dry gas seals. However, when SiC is paired in a “hard-on-hard” way under dry friction conditions, severe adhesive wear is likely to occur, often showing characteristics of high friction and high wear, which greatly affects the service life of the SiC seal ring. This paper aims to improve the tribological properties of SiC-SiC pairs through surface texturing. It explores the influence of texture size and areal density on the tribological properties of SiC. Regarding research methods, using laser processing technology, 45° elliptical textures with different sizes and areal densities were fabricated on the surface of SiC ceramics. A SiC ball with a diameter of 6 mm was chosen as the friction counterpart, and tribological performance tests were conducted in a ball-on-disc reciprocating manner. A 3D laser confocal microscope was employed to observe the wear scars and calculate the wear rate. A scanning electron microscope was used to observe the microscopic morphology of the wear scars and to explore the influence laws and mechanisms of texture size and areal density on the tribological properties of SiC. The research results indicate that adhesive wear and brittle spalling of SiC occur on the surface of the base material. In contrast, on the textured surface, adhesive wear mainly occurs between the textures perpendicular to the friction direction. Additionally, as the texture size and areal density increase, the average friction coefficient and wear rate first decrease and then increase. The optimal friction and wear performance is achieved when the equivalent diameter is 80 μm and the areal density is 10%, with the friction coefficient and wear rate decreasing by 15.6% and 41.8% respectively compared to the base material. In summary, textures with a reasonable structural design can serve functions such as accommodating wear debris and reducing the friction area, significantly alleviating three-body wear and adhesive wear, thus positively enhancing the SiC surface's tribological properties. The smaller the texture size, the more textures there are in the wear scar, and the more obvious the scratching effect. As the texture size increases, the number of textures in the wear scar decreases, the scratching effect is alleviated, and the friction coefficient and wear rate decline. However, when the texture size is too large, the counter-face ball may sink into the texture, increasing the acting force, and causing significant fluctuations in the friction coefficient during the running-in stage and an overall increase in the friction coefficient and wear rate. When the areal density of the texture is relatively small, the textured surface approaches that of the base material, and the friction-reducing and wear-resistant effects are weak. A moderate increase in the areal density can reduce adhesive wear and enhance the debris-accommodating effect, resulting in good friction-reducing and wear-resistant effects. However, if the areal density is too large, due to the excessively small friction area and high discontinuity, local stress concentration may occur, and the large number of textures may intensify scratching, causing severe abrasive wear. Only when the texture has appropriate size and surface density can it play its role in accommodating wear debris, reducing contact area, reducing abrasive wear and adhesive wear, and improving the tribological properties of SiC.

To investigate the performance of perfluorinated branched short chain fluorocarbon surfactant complex system, perfluorobranched short-chain quaternary ammonium fluorocarbon surfactants (BQSF-IEt) and sodium hexanesulfonate (SHS) are used as the objects, and the critical micelle concentration (CMC), critical surface tension (γ_CMC), aggregation behavior, interaction parameters, and wetting properties of the BQSF-IEt/SHS complex system are studied. The results show that SHS can significantly improve the surface activity of BQSF-IEt solution. It is worth noting that the surface activity of the solution is strongest when the compounding ratio (BQSF-IEt/SHS) is 1∶2, γ_CMC and CMC are 16.23 mN/m and 0.0065 mmol/L, respectively. At the same time, the addition of SHS will also change the size of BQSF-IEt vesicles in the solution. Moreover, through the relevant calculations of the Clint and Rubingh models, it is revealed that there is a strong interaction between BQSF-IEt and SHS. Besides, BQSF-IEt/SHS solution has strong wettability and can almost completely wet PTFE plates with low surface energy at low concentration (0.1667 mmol/L). Therefore, BQSF IEt/SHS can be used as a potential high-efficiency cleaning agent for low-energy surfaces.

Surface tension is an important physical property parameter of liquid, one of the key factors affecting various chemical reactions and biological reactions, and an essential basic physical property parameter in chemical engineering calculations. The oscillating sessile drop method is a highly precise and sensitive technique for measuring the surface tension of liquids. To discuss the effectiveness and influencing factors in measuring liquid surface tension using the oscillating sessile drops method, distilled water, ethanol and glycol used as experimental objects at 20℃, and stainless-steel needles with different outer diameters used to drop droplets on the polyethylene terephthalate (PET) substrate, the oscillation behaviour of droplets was recorded by high-speed camera, and the frequency spectrum was analyzed. The experimental results show that although the surface tension calculated based on Rayleigh equation is generally higher than that measured by traditional pendant-drop method, there is a linear relationship between oscillation frequency and droplet volume. In addition, the experiment also verified the influence of different image acquisition frame rates on the spectrum analysis results. The research shows that the oscillating sessile drop method is a potential measurement method, especially suitable for measuring the surface tension of metallurgical melt at high temperatures. However, the surface tension calculated by this method is still higher than the standard value, which suggests that the model needs to be further optimized to improve the measurement accuracy.

Liquid self-impact sealing is a novel non-contact sealing technology that offers advantages such as zero wear, low energy consumption, long lifespan, and high stability, meeting the stringent sealing requirements under high-pressure and high-speed conditions. Through numerical simulations and multi-condition analyses, this paper systematically investigates the leakage characteristics and sealing mechanisms of wing-shaped, rectangular, and key-shaped suspension column structures, and proposes an optimized design method for parallel flow channels based on an analogy to Ohm's law. The study reveals that: (1) The wing-shaped suspension column structure exhibits the best leakage suppression capability under conditions of low-viscosity gas, high pressure (≥4 MPa), high speed (≥11000 r/min), and large clearance (≥0.18 mm). Its performance is attributed to the “impact blocking” effect resulting from the synergistic effect of branch channel reflow and multiple vortices; (2) The key-shaped and rectangular structures perform similarly in scenarios involving high-viscosity liquids, low pressure (≤4 MPa), and small clearance (≤0.18 mm), with the key-shaped structure exhibiting better sealing effectiveness; (3) The leakage suppression gain is significantly weakened after the sealing level exceeds 20, and the gap reduction needs to balance the processing cost and reliability; (4) By analogizing the principle of parallel circuits, an optimization scheme is proposed where the width of the branch channels is 0.5 times that of the main channel, and the applicability of this method to high-viscosity laminar flow media is verified (error <5%). This study elucidates the flow mechanism of liquid self-impact sealing, providing a theoretical basis for low-leakage and high-stability sealing designs in high-pressure equipment, and simultaneously expanding the engineering application scenarios of the “impact blocking” concept.

Hydroxyl-terminated polybutadiene (HTPB) is an important component of butyl hydroxy propellant. The disposal of waste butyl hydroxy propellant, resulting from the retirement and upgrading of weapons, poses notable environmental challenges. In this study, a Pseudomonas sp. HM6 was isolated from refinery sludge, which used HTPB as the sole carbon source. The molecular mass distribution of HTPB before and after degradation was determined by using gel permeation chromatography. The degradation products were characterized by using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and gas chromatography-mass spectrometry. After degradation, the degradation products exhibit two distinct molecular mass,which decreased from an initial value of 9523 g/mol to 6809 g/mol and 366 g/mol. The degradation products contained aldehydes, alcohols, and carboxylic acid compounds. Through genomic and transcriptional analysis, genes encoding copper oxidase, aldehyde dehydrogenase, hydrolase and other genes were found, and their expression levels were upregulated. Based on chemical characterization and genomic analysis, a degradation pathway of HTPB by strain HM6 was proposed. This study provides a theoretical basis for the use of microorganisms to degrade waste butyl hydroxyl propellant.

A self-pressurization model of vacuum multi-layer insulation (VMLI) liquid hydrogen tank coupled with vapor-cooled shield (VCS) is constructed using MATLAB, and the effects of the dimensionless position l_d of VCS, the mass flowrate in VCS {\dot{m}}_{\mathrm{v}\mathrm{c}\mathrm{s}} and the opening moment of VCS t_open on the dormancy of tank are investigated. The dormancy is defined as the duration for tank pressure to rise from the initial pressure to the termination pressure, which is represented by a dimensionless dormancy extension factor {\lambda }_{\mathrm{d}}. Parameters {\lambda }_{\mathrm{c}} and t_d are defiend to represent the mass of hydrogen consumed by VCS and duration time when VCS remains opened respectively; the multi-objective genetic algorithm is introduced to help search for the optimized ({\dot{m}}_{\mathrm{v}\mathrm{c}\mathrm{s}}, t_open, t_d, l_d) in the high-dimensional input parameter space, achieving a Pareto-optimal state for {\lambda }_{\mathrm{c}} and {\lambda }_{\mathrm{d}}, and the resulting set of optimized points ({\lambda }_{\mathrm{c}}, {\lambda }_{\mathrm{d}}) forms the Pareto front. The Pareto front can be approximated as a straight line passing through the origin, with its slope determining the theoretical limit of {\lambda }_{\mathrm{d}} under fixed {\lambda }_{\mathrm{c}}, indicating the maximum dormancy achievable given a specific hydrogen consumption by VCS. When TVCS (triple vapor-cooled shields) is adopted, the three optimized points ({\dot{m}}_{\mathrm{v}\mathrm{c}\mathrm{s}}, t_open, t_d, l_d) in the high-dimensional input parameter space are compared with the initial point by evaluating their corresponding ({\lambda }_{\mathrm{c}},{\lambda }_{\mathrm{d}}). It is found that {\lambda }_{\mathrm{c}} corresponding to the optimized points 1, 2 and 3 are reduced by 5.57%, 18.60% and 31.57% respectively, while {\lambda }_{\mathrm{d}} increase by 64.57%, 42.60% and 20.25% respectively; it indicates that by optimizing the input parameters, the dormancy period is extended when the amount of hydrogen consumed by the VCS is reduced. The research can provide theoretical guidance for improving the utilization efficiency of cold energy in VCS and the efficient storage of liquid hydrogen.

Based on the action mechanisms of solid promoters and chemical promoters, the effects of CP hydrate seeds + THF solid-liquid compound promoters on the formation of CO₂ hydrates in brine systems and their influences were studied. Through macroscopic experiments combined with characterization methods such as laser Raman spectroscopy and scanning electron microscopy (SEM), the influence laws of different concentration combinations of the solid-liquid compound promoters on the growth kinetics, gas consumption, and hydrate morphology of CO₂ hydrates were obtained. The experiments showed that the synergistic effect of CP hydrate seeds + THF effectively improved the formation efficiency and rate of CO₂ hydrates; In the brine system, when the optimal molar fraction combination was 2.78% CP + 2.78% THF, the CO₂ gas consumption reached 23.90 mmol and the average formation rate of hydrates was 2.94×10^-⁴ mmol/(mol·s), which was 15.00% and 66.67% higher than the results previously reported, respectively. In addition, microscopic analyses by SEM and Raman spectroscopy reveal that, in a pure water system, hydrate formation is diffusion-controlled and characterized by high gas consumption. By contrast, in a brine system, hydrate formation is limited by surface reactions, and the electrostatic effect of salt ions makes the hydrate interface denser, thereby significantly reducing the gas consumption. The experiments simulating the process of CO₂ hydrate sedimentation in marine environment have shown that the CO₂ hydrates synthesized in salt water have a higher density and are more prone to sedimentation, which is more conducive to marine carbon sequestration. These microstructure characteristics were consistent with the macroscopic experimental data, verifying the effectiveness of the solid-liquid compound promoter system. This achievement provides a key parameter optimization scheme and theoretical support for marine carbon sequestration technology, and has important application value for achieving efficient and stable marine carbon dioxide sequestration.

Fe-Zn/Al₂O₃ adsorbents exhibit good performance in H₂S removal; however, the high raw material cost and complex preparation process increase the application costs in large-scale biogas purification systems. To reduce these costs, this study explores the potential of partially replacing Fe-Zn/Al₂O₃ adsorbents with fly ash (FA) from sewage sludge incineration to enhance biogas desulfurization. The results show that the Zn-Fe/Al₂O₃ composite adsorbent with a Zn/Fe molar ratio of 3∶1 has the best H₂S removal performance at room temperature, and its penetration capacity reaches 3.234 mg/g. Further addition of FA as a preliminary desulfurizer in a two-step adsorption process significantly increased the overall H₂S breakthrough capacity by 7.4%. This study demonstrates that incorporating FA can effectively reduce biogas desulfurization costs, offering a promising approach for large-scale applications.

To investigate the lean combustion and emission characteristics of ammonia-methanol mixed fuels under high pressure, a visual study of their laminar flame propagation characteristics was conducted in a constant-volume combustion chamber. Additionally, chemical reaction kinetics analysis was performed based on a self-developed mechanism. It was found that as the methanol energy proportion increased, the laminar flame propagation speed significantly increased, and the stability of the flame improved. When the methanol energy proportion increased from 20% to 50%, the laminar combustion speed at Φ=0.7 and Φ=0.8 increased by 110% and 99.6%, respectively. In terms of emissions, the main formation pathways of NO are HNO+M\stackrel{}{̿}H+NO+M and HNO+H\stackrel{}{̿}H₂+NO, while the main consumption pathways of NO are NH₂+NO\stackrel{}{̿}NNH+OH and NH₂+NO\stackrel{}{̿}N₂+H₂O. Under lean-burn conditions, the presence of intermediates like HNO leads to an increase in NO emissions. Comprehensive analysis shows that under lean-burn conditions, NO generation is mainly carried out through the oxygen enrichment reaction pathway, and fuel-type NO is dominant. Therefore, although increasing methanol content can improve laminar burning velocity, it is necessary to balance this with NO emissions.

Hydrogen storage is a core issue that hinders the development of the hydrogen energy industry, and improving hydrogen storage density is a key technical difficulty. Metal-organic frameworks (MOFs) exhibit excellent hydrogen storage density, and have become one of the most promising energy storage materials. However, conventional computational approaches, including traditional molecular simulations and high-throughput screening methods, encounter significant limitations when applied to MOF hydrogen storage research. These methods are particularly constrained by their excessive computational time requirements and substantial resource consumption, which hinder efficient material discovery and optimization. To address these challenges, this study developed a data-driven high-throughput screening strategy for the rapid prediction of hydrogen storage performance in anion-templated metal-organic frameworks (AP-MOFs). The proposed method achieved exceptional predictive accuracy, with R² values exceeding 0.99 for both the training and test sets, and required only 63 s of computation time. Through this approach, 20 AP-MOFs with a hydrogen storage density exceeding 5.5%(mass) at 77 K and 5 MPa were identified, surpassing the hydrogen storage target set by the United States Department of Energy. Among these, the ALFFIVE_2_Fe structure, which is potentially synthesizable, exhibited a remarkable hydrogen storage density of 9.75%(mass) under the same conditions, along with a deliverable hydrogen storage density of 3.05%(mass). The study also revealed that the volumetric porosity has the greatest impact on hydrogen storage performance, followed by gravimetric surface area, density and porosity. These findings provide theoretical insights for the future application of AP-MOFs in hydrogen storage technologies.

To address the limitations of traditional Fenton systems, such as the requirement for low pH conditions and the limited availability of active iron, this study proposes a modified approach by incorporating bicarbonate into the Fenton system. The bicarbonate reacts with H₂O₂ to generate HCO{}_{\mathrm{4}}^{-}, which is further enhanced by HAH to achieve efficient degradation of 2,4-DCP under the near-neutral conditions. The results show that HAH enhanced HCO{}_{\mathrm{3}}^{-} modified Fenton system under the condition of pH about 6.46, when the concentrations of Fe²⁺, NaHCO₃, H₂O₂ and HAH are 4, 10, 10 and 0.5 mmol·L^-1, 2,4-DCP can be completely degraded after 60 minutes of reaction. However, the degradation efficiency was found to be inhibited by high concentrations of \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}, Cl^- and coexisting organic matter. The introduction of HAH into the reaction system facilitated the redox cycling of Fe²⁺ and Fe³⁺, thereby enhancing the catalytic efficiency of the system, and reducing the required dosage of Fe²⁺. Free radical quenching experiments and EPR detection experiments confirmed that HO^· were the primary reactive species involved in the degradation process, while the contributions of ¹O₂ and {\mathrm{O}}_{\mathrm{2}}^{·-} were relatively minor. Toxicity assessment results indicate that most of the organic intermediates generated during the degradation process have significantly reduced toxicity compared to 2,4-DCP.

Porous liquid (PLs) is a new kind of material with stable permanent pore structure and fluidity. A type Ⅲ porous liquid was synthesized with 2-methylimidazole zinc salt (ZIF-8) nanoparticles as the main body and 1-ethyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide ([EMIm][NTf₂]) as the steric inhibitor. The effects of ZIF-8 loading, SO₂ concentration, SO₂ flow rate and temperature on the adsorption performance of PLs were studied. The results show that PLs has certain fluidity, thermal stability and permanent pore structure. The addition of ZIF-8 can significantly improve the SO₂ adsorption capacity of ionic liquid steric inhibitor. When the loading capacity of ZIF-8 is 25%, the saturation adsorption capacity of PLs for SO₂ (0.41 mmol/g) is much higher than that of pure ionic liquid (0.05 mmol/g), the synergistic effect of ZIF-8 and ionic liquid reaches 61.6%, and the adsorption rate of ZIF-8 is higher (0.37 mmol/(g·min)). The adsorption behavior of PLs for SO₂ conforms to the Avrami adsorption kinetics model. PLs mainly adsorbs SO₂ through the interaction of chemical bond and van der Waals force. PLs still has high adsorption capacity after 4 times of regeneration.

To reveal the migration and transformation mechanisms of organic Ca in coal during hydropyrolysis, this study constructed a macromolecular structural model of coal containing carboxylic acid-bound Ca. The reactive force field molecular dynamics (ReaxFF MD) simulations were employed to track the atomic-level trajectory of Ca during hydropyrolysis under different heating modes. Hydropyrolysis experiments were conducted by using Ca-loading treatment, and the content of Ca in the resulting products was analyzed by using an inductively coupled-plasma optical emission spectroscopy (ICP-OES). The simulation results show that during the heating simulation process, organic Ca migrates to inorganic Ca, gaseous hydrocarbon Ca, and tar Ca at high temperature. Atomic Ca is challenging to release directly from char and readily combines with generated H₂O molecules. Under constant-temperature simulations, as the temperature increases, the migration of organic Ca intensifies, with substantial conversion of coke-associated Ca into inorganic Ca and Ca in gaseous hydrocarbons. At lower temperatures (1600—2200 K), organic Ca requires more time to transition, whereas at higher temperatures (2500—2800 K), this process accelerates significantly. By analyzing the evolution of Ca in the pyrolysis experiment, the simulation results are preliminarily verified. In addition, the effect of macerals on the migration behavior of organic Ca was also discussed. Vitrinite, containing abundant aliphatic chains, undergoes thermal decomposition to generate more small molecular fragments capable of binding with Ca. In contrast, inertinite exhibits relatively weaker organic calcium binding capacity due to its compact aromatic structure and limited active sites available for interaction. Ultimately, the transition mechanism of organic Ca during hydropyrolysis was elucidated: organic Ca exhibits strong binding capacity and readily combines with small molecules after decomposition. It is predominantly converted into inorganic small molecules, followed by gaseous hydrocarbons and tar molecules. Additionally, Ca migrates and transforms between these forms under high temperatures. These results can provide scientific reference and theoretical support for pollution control and product optimization of high alkali coal in the low and medium temperature pyrolysis industry.

Prussian blue (PB) has attracted much attention in the field of electrochemical storage due to its three-dimensional frameworks. In this study, PB was dispersed into the electrolyte to form a stable suspension, allowing PB to co-deposit with discharge products during the discharge process of lithium oxygen batteries (LOBs). The high lithium-ion (Li⁺) migration number (t_{\mathrm{L}{\mathrm{i}}^{+}}=0.67) offered by the incorporated PB accelerated the decomposition of discharge products and reduced the charging voltage. At the same time, the suspended PB promotes the homogenization of Li⁺ flux, which is beneficial to the uniform deposition and dissolution of lithium. Compared with the LiClO₄/DMSO electrolyte, the lifespans of lithium || lithium (Li||Li) symmetric batteries were extended from 257 h to 1000 h with 1.5 mg·ml^-1 PB suspension electrolyte, and the cycle numbers of LOBs were extended from 64 rounds to 430 rounds.

Direct reduced iron-electric arc furnace (DRI-EAF) is a short steelmaking route for decarbonization in the iron and steel industry. Its large-scale green hydrogen metallurgical application needs to pay attention to renewable energy utilization, time-series source-load interaction, and economic feasibility. This work established an integrated model of hydrogen-based DRI-EAF plant co-driven by photovoltaic and power grid. The energy consumption, carbon emission and economic benefits of the process were evaluated based on the technical and economic parameters of typical geographic regions in China. The results show that a renewable energy share ratio of 90.26% could be achieved with the scale of 2500 MW photovoltaic station in Urumqi, Xinjiang. Carbon emissions are reduced by 84.54%, 81.35% and 68.28% compared to grid-only operation, blast furnace-basic oxygen furnace route and natural gas based DRI-EAF process, respectively. At the scale of 100 MW photovoltaic station, Shanghai is difficult to pay back the initial investment cost since its grid electricity price is too high. Regional grid electricity price is one of the key factors influencing the economics of hydrogen-based DRI-EAF process integrated with renewable energy. When the hydrogen production cost is fixed, as the carbon price rises from 90 CNY/t to 1614 CNY/t, payback period of the 2500 MW photovoltaic project in Urumqi, Xinjiang decreases from 8.28 years to 3.45 years.

Firstly, polymerizable cationic Gemini surfactants PC11-n-11(n=2, 4, 6) with different linker chain lengths were synthesized,the structure was characterized by ¹H NMR and FTIR. Secondly, the interfacial properties, micelle diameter distribution, wetting properties and high internal phase emulsion (HIPE) stability of PC11-n-11 were studied. The results demonstrate that the interfacial properties of the prepared PC11-n-11 are significantly superior to those of the conventional surfactant (DTAB), with enhanced wetting performance. As the spacer chain length increases, CMC and Γ_max gradually decrease, while A_min gradually increases, leading to improved interfacial properties. Among them, PC11-4-11 and PC11-6-11 have good stability to HIPE. The porous polymer composite of chitosan and polyacrylamide was successfully prepared by the HIPE template method using PC11-6-11 as a stabilizer.

To study the effects of particle size on the deflagration behaviors and temperature distribution characteristics of TiH₂ dust cloud, a 20 L spherical dust explosion test system and a 1.2 L Hartmann tube test system were employed to conduct a comparative analysis for the deflagration characteristics of TiH₂ dust clouds with different particle sizes of 5.3, 17.1 and 27.8 μm. Additionally, flame temperature distribution characteristics were obtained by the two-color pyrometer technique. The experimental results showed that with the increase of dust concentration, the P_max and (dP/dt)_max values of the TiH₂ with three particle sizes all increased first and then decreased. As the particle size of TiH₂ dust increased, the values of P_max, (dP/dt)_max and K_St all decreased, and consequently lowered the explosion risk. Furthermore, as the dust particle size enlarged, the flame was more dispersed, the luminous intensity decreased and the propagation speed was slower. The overall flame temperature distribution of small-particle TiH₂ dust cloud is more uniform, and local high-temperature areas appear at the edge of the flame of large-particle TiH₂ dust cloud. The larger the particle size, the more obvious the local high-temperature area, and the more irregular the flame shape. The research results could provide theoretical reference for the safe production and explosion prevention of TiH₂ powder materials.