Hydrogen is regarded as a safe and sustainable supply of clean energy, which plays a very important role in alleviating the shortage of fossil energy and environmental pollution. Electrocatalytic water splitting is one of the effective ways to produce hydrogen. MoS2 has been widely used in electrocatalytic hydrogen evolution reaction because of its low
Based on the background of 'dual carbon' , the chemical chain hydrogen production process is a novel alternative to traditional hydrogen production schemes, with economic and efficient characteristics. Choosing appropriate oxygen carriers is crucial for the stability of the process, as they require high reactivity, selectivity, material strength, and sintering resistance. This article provides an overview of commonly used chemical chain processes, including dual reactors and triple reactors, and compares the performance of several different metal oxygen carriers in depth. At the same time, summarizing the reaction mechanisms of different oxygen carriers is helpful for selecting appropriate oxygen carriers in the process. Due to the phenomenon of coking and agglomeration of oxygen carriers during the reaction process, numerous researchers have paid significant attention to its avoidance at the micro level. Finally, the prospects of the oxygen carrier used as a renewable, sustainable and environmentally friendly material are prospected.
The pollution of tetracycline antibiotics in the water environment is increasingly serious, and the effective removal of residual antibiotics in water is an urgent problem to be solved. The co?precipitation method was used to prepare Cu?Al layered double hydroxides biochar composites (CuAl?LDH@BC) intending to remove tetracycline hydrochloride (TCH) from water. The physicochemical properties of the CuAl?LDH@BC surface were analyzed by SEM, XRD, and FTIR, and the adsorption performance of the tetracycline hydrochloride solution was revealed. The experimental results show that the adsorption process is more consistent with the quasi?second?order kinetic model and Langmuir model, and the maximum adsorption capacity of TCH is 78.68 mg/g at 298 K, and the neutral condition CuAl?LDH@BC has the best removal effect on TCH, which has strong anti?interference ability in water environment. The mechanisms involved in the adsorption of TCH by CuAl?LDH@BC may include hydrogen bonding, surface complexation, π-π interaction, and electrostatic interaction. The results show that Cu?Al layered double hydroxides and biochar composites, as low?cost and high?efficiency adsorbents, have a broad application prospect in the adsorption of tetracycline antibiotics in water.
In order to explore the preparation process of graphene?reinforced composite materials with industrial development prospects, graphene/polypropylene composite materials were prepared using the melt blending method, and the graphene reinforcement mechanism was analyzed through experimental and computational analysis. The results indicate that through melt blending, graphene can be uniformly dispersed in the matrix. The tensile strength of the composite material with a graphene mass fraction of 0.5% is 50.3 MPa. When the mass fraction of graphene is 4.0%, the elastic modulus and tensile strength of the composites are increase by 77.1% and 22.5%, respectively, compared to the polypropylene matrix alone. The uniform dispersion of graphene and the interaction between graphene and the polypropylene matrix enable effective stress transfer at the graphene/polypropylene interface.
Carbon fiber reinforced epoxy resin matrix composites with light weight and high strength are widely used in aerospace, transportation, energy and other fields. The composition and structure of the interface are the main factors affecting the physical and chemical properties of composites. Surface modification of carbon fiber is one of the most effective ways to enhance the interfacial properties and mechanical properties of carbon fiber composites. In recent years, it's been found that porous materials with large specific surface area and diverse structures can improve the surface energy and surface roughness of carbon fibers and improve the interfacial properties of composites. This paper briefly introduces the modification of carbon fiber with different kinds of porous materials in recent years, and summarizes the interfacial strengthening effect of carbon fiber composites, which provides reference significance for the future research of porous materials reinforced carbon fiber composites.
Superhydrophobic materials have become one of the research hotspots in coating directions in recent years because of their special wetting properties. Due to their anti?icing, self?cleaning, drag reduction and other characteristics, it has a wide range of application prospects. In this paper, SA?SiO2/PPSsuperhydrophobic coatings with a thickness of about 38 μm were prepared on the surface of textile cloth using nano silica (SiO2), stearic acid (SA) and polyphenylene sulfide (PPS) as raw materials by sol?gel method. The morphology was analyzed by electron scanning microscope, and the properties of the sample coating were tested. The microcosmic properties of the coating were analyzed by molecular dynamics simulation. The results show that the water contact angle of 56%SA?SiO2/30%PPS coating is 154.8°, which shows good self?cleaning, corrosion resistance and soaping resistance. Scanning electron microscopy (SEM) analysis shows that the material has micro and nano?scale rough structure. The surface of SiO2 and SA molecules was connected by hydrogen bond. The molecular dynamics simulation was consistent with the experimental data, and the corrosion resistance of the coating was verified from the microscopic point of view.
Dehydration of crude oil is an important step in the production and processing of crude oil. As oil fields enter the high water cut stage of production and the addition of oil recovery additives, dehydration becomes increasingly difficult, so the use of high?frequency electric fields for electric demulsification has become an effective means of dehydration. This article investigates the mechanism of electric dehydration under high?frequency electric field through static dehydration experiments and numerical simulations of droplet electric coalescence. It is found that the electric field strength, frequency, and duration have significant impacts on dehydration efficiency when treating crude oil with electric demulsification and dehydration. In the process of electric demulsification and dehydration, there is an optimal electric field frequency. After the electric field strength increases to a certain value, continuing to increase the electric field strength will actually lead to an increase in water content. After the electric field action reaches a certain time, continuing to increase the electric field action time will result in little change in the water content of crude oil; the greater the electric field strength applied to droplets in the electric field, the more likely the droplets are to deform, and the larger the diameter of the droplets, the more likely they are to deform; compared with the power frequency electric field, droplet coalescence efficiency is higher under high?frequency electric field, and droplets are more prone to coalescence. The research results provide theoretical support for the design and parameter optimization of crude oil electric dehydration units.
In view of the influence of different factors on the leakage and diffusion of hydrogen?doped natural gas pipelines in the pipe gallery, the leakage and diffusion model of hydrogen?doped natural gas pipelines in the pipe gallery was established by numerical simulation software, and the influence of factors such as hydrogen doping ratio, pipeline pressure,leakage hole size and the model of ventilation on the gas diffusion process was studied. The results show that the hydrogen blending ratio can affect the mass transfer ability of hydrogen?doped natural gas, and the higher the hydrogen blending ratio, the faster the diffusion rate of hydrogen?doped natural gas. The pipeline pressure and leakage hole size mainly affect the leakage gas diffusion by affecting the initial kinetic energy and leakage volume of the leakage gas, and the leakage gas diffusion range becomes larger with the increase of pipeline pressure and leakage hole size. The ventilation mode plays a dominant role in the distribution of leaked gas in the pipe gallery, and the ventilation frequency is inversely proportional to the height of the leaked gas jet.
Offshore oilfield development faces complex geological conditions and high development costs, with limited platform lifespans and well locations. These constraints reduce the effectiveness of chemical flooding for enhancing oil recovery. Based on the geological characteristics of offshore oilfields, and drawing on the results of synergistic enhanced oil recovery (EOR) techniques combining chemical flooding and infill well patterns in Daqing, Dagang, and Shengli oilfields, this study evaluates the synergistic potential of chemical flooding agents, well pattern infill, and layer adjustment. The synergy between chemical flooding and infill well pattern optimization for enhanced oil recovery was established. Relying on numerical simulation, an optimized design for synergistic chemical flooding and infill well patterns was developed for the SZ36?1 oilfield. The effects of reservoir permeability, permeability heterogeneity, and crude oil viscosity on enhanced oil recovery potential were clarified, along with the establishment of corresponding boundaries. The study demonstrated that after the original inverted nine?spot well pattern is encrypted into an oblique inverted nine?spot well pattern, the well spacing is reduced by half. Combined with polymer flooding technology, the recovery rate can be increased by 9.8%, which is 3.4% higher than the sum of the recovery increases achieved by independent water flooding and polymer flooding. This result confirms that by utilizing the synergistic effect of chemical flooding and infill well pattern technology in offshore oilfields, the sweep efficiency of the oil displacement system can be significantly enhanced, leading to a substantial increase in recovery rates and optimization of production capacity.
As the global energy structure transitions toward cleaner and more sustainable sources, natural gas, as a low?carbon and environmentally friendly fossil fuel, continues to see increasing consumption. However, with the ongoing expansion of natural gas pipeline networks, the growing coverage areas, and the significant increases in both transportation distances and volumes, the safe operation of pipelines is facing unprecedented challenges, with pipeline leakage emerging as a particularly critical issue. In response to the long?term monitoring needs of oil and gas pipeline leaks, based on the principle of negative pressure wave detection, a highly efficient and reliable pipeline leakage monitoring simulation system was developed using LabVIEW, a powerful graphical programming platform. This system incorporates advanced sensor networks, data communication technologies, and signal processing algorithms. It was used for the leakage monitoring of oil and gas pipelines, and its performance was verified through experiments. The results show that the system is capable of detecting pipeline leakage and rapidly locating leakage points through efficient algorithms, providing crucial information for timely repair and ensuring the safety and stability of oil and gas pipelines.
The fracture damage of oil and gas pipelines usually initiates from micro?cracks. The weak magnetic detection method is of practical significance for the detection of microcracks in long distance oil and gas pipelines. However, the microstructure of pipeline microcracks is complex, and the traditional weak magnetic field detection model is difficult to achieve accurate quantitative calculation of pipeline microcracks. Based on the theory of magnetoelectric coupling, a mathematical model of weak magnetic signal of pipeline micro?crack is established. The weak magnetic signal of micro?crack under different excitation conditions is compared and analyzed. The propagation characteristics of micro?crack at different depths and the signal detection characteristics under different lifting values are analyzed and calculated. The results show that the weak magnetic signal generated by the microcrack is much larger than the geomagnetic field, and the difference increases as the increase of the stress value. The weak magnetic signal increases with the increase of stress value. When the critical point of microcrack propagation is reached, the magnetic energy is released due to microcrack propagation, and the weak magnetic signal decreases with the increase of stress value. After microcrack propagation, the magnetic sensitivity of the material decreases, but the linear characteristics are more obvious. The larger the crack depth is, the stronger the weak magnetic signal is, and the damage is more easily detected. With the increase of the lift value, the weak magnetic signal decreases exponentially, and the detection accuracy of the signal in the linear region is the highest.
An amorphous NiP?WC composite coating was prepared on a copper substrate by chemical plating. The corrosion resistance of the coating was studied in a NaCl solution with a mass fraction of 3.5% and a 1 mol/L hydrochloric acid solution. The surface morphology, composition, and microstructure of the coating were characterized by scanning electron microscopy (SEM), Energy dispersive spectrometer (EDS), and X?ray diffraction (XRD). The corrosion resistance of the coating was analyzed by potentiodynamic polarization and impedance spectroscopy. The results show that in a NaCl solution with a mass fraction of 3.5%, the self corrosion potential of NiP?WC coating shifted approximately 111 mV higher as compared to amorphous NiP coating, resulting in a decrease of approximately 68.8% in self corrosion current density and an increase of approximately 6.7 times in charge transfer resistance. Soaking in 1 mol/L hydrochloric acid solution, the corrosion rate of NiP?WC coating decreased by about an order of magnitude compared to NiP coating, indicating that uniformly distributed WC particles can significantly improve the corrosion resistance of amorphous NiP.