Aromatic?based green rubber filler oil is prepared from furfural extraction oil of a petrochemical company by using compound solvents for secondary extraction to separate polycyclic aromatic hydrocarbons present in the oil. Three composite solvents are used for comparison, and the effects of operating conditions, such as extraction temperature and agent?oil mass ratio, on the yield and PCA mass fraction of the refined oil are investigated. A detailed compositional analysis is conducted using the alumina adsorption column method and infrared spectroscopy. The experimental results demonstrate that the optimal operating conditions are primary solvent extraction at 70 ℃ and an agent?oil mass ratio of 5∶1, and secondary solvent extraction at 50 ℃ and an agent?oil mass ratio of 2∶1. The yield of refined oil is 32.34%, the mass fraction of PCA is 2.98%, and the aromatic carbon ratio is 18.65%. These results meet the requirements outlined in EU Directive 2005/69/EC. The results demonstrate that the composite solvent significantly enhances the selectivity and solubility of the solvent, effectively removes PAHs from the oil, and ensures a high product yield and aromatic carbon ratio.
Biochar with developed pore structure was prepared by using high?humidity Chinese herbal medicine wastes (CHMWs) as raw material, using the water vapor generated by its own water under a high temperature environment for physical activation,and the effects of moisture content, activation temperature and activation time on the performance of biochar were investigated. The performance of biochar was analyzed by physical adsorption instrument, Fourier transform infrared spectroscopy, scanning electron microscopy and other instruments, and the optimal reaction conditions for biochar preparation were obtained, and the activation mechanism of biochar prepared from CHMWs was discussed. The prepared biochar was used to adsorb wastewater containing Cd2+ and Cu2+, and the adsorption kinetics were discussed. The experimental results showed that under the conditions of 700 ℃ heating temperature, 60 min heating time and 50% moisture content of the CHMWs, the biochar with a specific surface area of 309.29 m2/g and a pore volume of 0.116 8 cm3/g and was obtained. The experimental results of adsorption showed that the adsorption kinetics on Cu2+and Cd2+ conformed to the quasi second order kinetic equation, and the optimal adsorption capacities of Cu2+ and Cd2+ were 20.66 mg/g and 17.41 mg/g respectively.
Metal?organic framework material MIL?53(Fe) was added as a modifier to polyvinylidene fluoride (PVDF) casting solution, and PVDF/MIL?53(Fe) composite membrane was fabricated. The composite membranes were characterized by a series of tests, including XRD, FT?IR, SEM and TG. The composite membrane was used as an adsorbent to adsorb Congo red (CR) from aqueous solution. The effects of composite membrane dosage, initial concentration of CR solution, contact time and temperature were discussed, and the isothermal adsorption models, adsorption kinetics, and adsorption thermodynamics were also studied. The results show that the most appropriate dosage of the composite membrane is 20 mg in each experiment. The maximum theoretical adsorption capacity of CR by the composite membrane is 71.9 mg/g at 313 K. Ethanol has good desorption effect on CR adsorbed onto the composite membrane, and the composite membrane can maintain good adsorption capacity after 5 adsorption?desorption cycles. The isotherm data follows the Langmuir isotherm model and the kinetic adsorption follows the pseudo?second?order model. This adsorption process is spontaneous and endothermic, which is illustrated by the thermodynamic data.
A novel adsorption material,KOH?C/CuO, was synthesized through the impregnation method using coconut shell activated carbon as support. The surface physical and chemical properties of the material were characterized by SEM,BET, FTIR,and XPS analysis. Subsequently, a benzene adsorption experiment was conducted to evaluate its performance. The influence of KOH concentration, modification time, CuO load(mass fraction), and adsorption temperature on the benzene adsorption properties was systematically investigated. Furthermore, a comprehensive evaluation of the materials' adsorption properties was carried out. The results indicated that the adsorption performance of 0.5K?C?4/CuO?3 reached its peak when the KOH concentration was 0.5 mol/L, the modification time was 4 h, the CuO load was 3%, and the temperature was maintained at 25 ℃. The adsorption capacity for benzene achieved a remarkable value of 235.3 mg/g, surpassing unmodified material by 118.88 mg/g.
Wellbore instability is easy to occur when drilling fractured shale formation. Based on mechanical experiments, this paper investigated the weakening law of mechanical properties of shale soaked in drilling fluid.Considering the influence of stress?pressure?temperature?solute concentration disturbance and natural fractures, a multi?field coupled thermal?hydraulic?mechanical?chemical wellbore stability analysis model of fractured shale formation was established.Based on the characteristics of wellbore instability, the window chart of safe drilling density in fractured shale formation with different rock strength parameters is established. The results show that with the increase of drilling fluid soaking time, the strength parameters and elastic parameters of shale deteriorate exponentially. Considering the non?uniform distribution of physical fields around the well after the development of natural fractures, the stress concentration at the crack tip leads to the collapse and tensile failure zone toward it. Increase of horizontal in?situ stress difference and fluid pressure difference will enlarge the tensile and collapse failure zone, and the increase of solute concentration difference will help reduce the failure risk. Increasing drilling fluid temperature has little effect on collapse failure, but it can significantly reduce the risk of tensile failure. The investigation can provide guiding suggestions for safe drilling design in fractured shale formation.
In the process of oil and gas field production, as well as in the gathering and transportation phases, the water jacket furnace coil serves as a crucial component for natural gas heating, playing a significant role in both heating and energy support. However, the presence of fine grit within the water jacket furnace coils can result in erosion damage that is challenging to predict. Therefore, it is essential to understand the factors influencing the erosion of water jacket furnace coils and to establish an effective predictive model. This study employs computational fluid dynamics (CFD) simulations and sensitivity analyses to investigate the effects of temperature, pressure, gas flow rate, particle diameter, bend diameter, and curvature radius on the erosion of water jacket furnace coils. The results indicate that the gas flow rate, particle diameter, bend diameter, and curvature radius are the primary factors affecting erosion. Consequently, a comprehensive erosion prediction model is developed, providing a scientific basis for equipment maintenance and safety management. The findings of this study offer a vital reference for addressing the erosion issues associated with water jacket furnace coils and hold practical significance in engineering applications.
Dome top tanks are important facilities for oil storage, and in order to reduce the evaporation loss of storage tanks, it is necessary to conduct research on their evaporation loss mechanism. Establishing a UDF for the absorption of heat flux at different times in a dome roof tank, and using FLUENT 19.0 software to simulate and analyze the effects of solar radiation intensity, oil storage height, and oil storage time on the diffusion of oil and gas inside the tank, the simulation results showed that: the gas temperature distribution inside the tank was uneven, with a vertical distribution of high and low, and the average gas temperature inside the tank decreased with the increase of oil storage height. The mass fraction of oil and gas in the tank is similar at the same oil level height, with the highest mass fraction on the oil surface. The vapor mass fraction is positively correlated with the oil storage height and storage time. The maximum pressure value of the gas inside the tank in a day first increases and then decreases, gradually increasing with the height of the liquid level. This study provides a basis for evaluating the evaporation loss of storage tanks and designing and managing oil and gas recovery systems
In order to break through the bottleneck of heat transfer efficiency of traditional printed circuit heat exchangers, a physical model of airfoil PCHE was established, numerical simulations were conducted to study the convective heat transfer of supercritical CO2 in the model, the heat conduction principles of supercritical CO2 under varying mass flow rates and inlet temperatures have been analyzed, and by changing the hydraulic diameter of the channel, further study the heat quantity transfer situation. The results indicate that the thermal exchange performance can be improved by increasing the mass flow rate and the inlet temperature of the cold fluid. At varied hydraulic diameter of the passage, the heat transfer capacity of PCHEs with chord lengths of 6 mm and 8 mm both increase with the increase of Reynolds number. When the Reynolds number is between 19 500 and 26 000, PCHEs with chord lengths of 6 mm and 8 mm have similar heat transfer performance; when the Reynolds number is between 26 000 and 50 000, the comprehensive performance of PCHE with a chord length of 8 mm is 2.55% higher than that of PCHE with a chord length of 6 mm. The research results provide a theoretical basis for the structural design of airfoil PCHE.
Three types of micro?textures, including broken line grooves, longitudinal grooves and 45° oblique grooves, were constructed on the tool surface and the influence of the tool surface micro?texture on the tool cutting performance during copper?nickel alloy cutting was deeply studied; by controlling a single?variable method, the influence of texture width, texture depth, texture spacing and cutting edge margin on the cutting performance was analyzed, the optimal texture parameter range of the longitudinal groove micro?texture was determined, and the optimal texture parameters were determined through orthogonal experiments. The results show that compared with the non?textured tool, the longitudinal groove micro?textured tool can effectively reduce the main cutting force and cutting temperature; the optimal texture width is 85 μm, the texture spacing is 40 μm, the texture depth is 30 μm, and the cutting edge margin is 40 μm; when the optimal micro?textured tool is used to process copper?nickel alloy, the average main cutting force is reduced by 23.07%, the average value of the maximum cutting temperature is reduced by 22.46%, and the average equivalent stress is reduced by 19.53%, indicating that the residual stress of the workpiece can be effectively reduced and the cutting performance can be improved.
Synchronous method is used to establish an integrated model for batch process production scheduling and control. In the scheduling section, a production scheduling model is established based on the State Equipment Network (SEN) and the unit?specific event?based continuous time modeling method; the integrated model of scheduling and control belongs to a mixed integer dynamic optimization problem, and solving it requires a large amount of complex computation, in order to alleviate the burden of online computing, Explicit Model Predictive Control (EMPC) is utilized for offline solving; the MPT toolbox is used to solve the dynamic problem of EMPC; introducing binary variables, converting the obtained explicit control solution into explicit linear constraints, and adding them to the common constraint objective in the scheduling model; through case analysis, the optimization results were compared and analyzed with the pure scheduling model, and the economic feasibility of the integrated model is verified.
The petrochemical industry is an important pillar industry in China, which is related to the security and stability of the industrial and supply chains, green and low?carbon development, and the improvement of people's well?being. By matching macro?level urban digitalization data with micro?level petrochemical enterprise data from 2012 to 2021, an empirical analysis was conducted to examine the impact of digitalization on the green total factor productivity of petrochemical enterprises. Additionally, the mechanisms through which digitalization enhances the green total factor productivity of petrochemical enterprises were investigated. Research has found that: Digitization has significantly improved the green total factor productivity of petrochemical enterprises; for the eastern region, regions with higher levels of digitalization, and petrochemical enterprises with smaller scale and state?owned property rights, digitalization has a greater impact on improving their green total factor productivity; the mechanism of digitalization to enhance the green total factor productivity of petrochemical enterprises is to enhance regional innovation, promote green innovation of enterprises, and accelerate digital transformation of enterprises. Finally, suggestions are proposed to actively embrace digitalization, formulate differentiated development strategies, and leverage the leading role of state?owned enterprises, aiming to provide reference and guidance for improving green total factor productivity of petrochemical enterprises in China.