The preparation of activated carbon from residue of a distillation reactor is an efficient and economical strategy for the utilization of hazardous waste resources.However,the prepared activated carbon is generally powdered,which is difficult to meet the requirements of industrial application.In this work,the activated carbon microspheres were prepared based on the rectification residue activated carbon from the powders,using deionized water as the solvent and polyacrylic acid (PAA),sodium alginate (SA) and Ca²⁺ as the additives.The effects of SA,Ca²⁺ and PAA amount on the structure and mechanical strength of the activated carbon microspheres were investigated.X?ray diffraction,Fourier transform infrared spectroscopy and Raman spectroscopy were used to investigate the shaping mechanism of activated carbon microspheres.The activated carbon microspheres were applied in the tetracycline adsorption,and the maximum adsorption capacity of tetracycline was up to 257.8 mg/g.At the same time,after 9 months of water stability test,the activated carbon microspheres still had good adsorption performance and mechanical strength. This shaping strategy adopted green and economical raw materials,which could effectively solve the problems of powder shaping and poor performance of microspheres,and provide the effective solution for the industrial application of high?performance materials.

Plasma modification is an effective way to improve the catalytic activities of materials.Firstly,Co₂(OH)₂CO₃ precursor was synthesized by a hydrothermal method.Then,the precursor was subjected to the oxygen atmosphere low?temperature plasma, and the surface modified Co₃O₄ catalyst (Co₃O₄?P) was obtained,which was further characterized the XRD,SEM,H₂?TPR,O₂?TPD,TEM,XPS,FTIR,Raman spectrum and UV?visible spectrum.The results demonstrate that plasma treatment could reduce the average valence state of Co elements in Co₃O₄ to form more defective sites on the catalyst surface,and lower the Co-O bond energy of Co₃O₄ to improve its low temperature reduction performance.Under the irradiation of full solar spectrum light with intensity of 776 mW/cm²,reaction space velocity of 30 000 mL/（g·h）and toluene concentration of 500 μg/g，the toluene degradation performance of the Co₃O₄?P catalyst could reach 100.0%，which was approximately twice that of the Co₃O₄ catalyst (Co₃O₄?T) prepared by thermal calcination.

Excessive CO₂ emission caused by a large number of human activities is the main cause of global warming,so a method to effectively control the increase in CO₂ concentration is urgently needed.Currently,direct air capture is the only technology capable of achieving negative growth of carbon emissions on a large scale.Solid amine adsorbents,especially silicon?based ones, have been widely studied and used to capture CO₂ from ambient air due to their advantages of high adsorption capacity,corrosion resistance,and low energy consumption.In this paper,silicon?based solid amine adsorbents were classified according to the mode of loading,and the influence of different silicon?based supports on the adsorbent performance was summarized.At the same time,the problems encountered in the industrial application of powdered solid amine adsorbents were put forward,and the current forming methods of solid amine adsorbents were sorted out.Finally,it is pointed out that the development of formed solid amine adsorbents with high adsorption capacity and high stability is the future trend of CO₂ adsorbent industrialization.

In this paper, Changqing crude oil was emulsified under pressure in different dissolved gas environments (CO2, CH4, N2) by using crude oil emulsifier with pressure dissolved gas. The solubility (Rs) , water separation rate (fv), interfacial tension (γ), interfacial modulus of elasticity (εd), viscosity of dissolved gas crude oil (μ) and apparent viscosity of dissolved gas crude oil emulsion (μap) were measured by means of solubility measurement device, emulsion stability analysis device, interfacial tension tester and high pressure rheometer. The results show that the presence of oil⁃water interfacial film inhibits the migration of gas from the outer phase to the inner phase to a certain extent, so that the solubility of the dissolved gas oil emulsion is less than the solubility of the internal and external phases. Under the environment of dissolved CO2, because of the minimum interfacial tension between oil and water, the best emulsification effect is obtained, and the W/O emulsion droplets with pressure are the most compact. Under the environment of dissolved CO2, because of its minimum interfacial tension between oil and water, the smallest droplets are formed in W/O emulsion and the emulsifying effect is the best. At the same time, due to the elastic modulus of oil⁃water interface is the largest, the emulsion system is the most stable, and the viscosity ratio of emulsion system is the most obvious than that of crude oil system. In contrast, in the environment of N2 dissolution, the stability of the emulsion system is poor, and it is easy to demulsify.

In this paper, the adsorption behavior of polyoctadecyl acrylate (POA) in model crude oil on the surface of nano⁃SiO2 particles modified by methyl was investigated by performing molecular dynamics (MD) simulations. The adsorption model of model crude oil including POA molecule on the surface of nano⁃SiO ₂ particles was constructed. The model crude oil consists of asphaltene, resin, aromatic hydrocarbons and alkanes. The surface of nano⁃SiO ₂ particles was modified with three different degree of methyl. Several parameters such as the adsorption energy, relative density distribution, the mean square displacement and radial distribution function were analyzed. The results show that the unmodified surface is firstly adsorbed by asphaltene of strong polarity while the surface of 100% methyl⁃modified is firstly adsorbed by n⁃alkanes. The surface of 50% methyl⁃modified particles is firstly adsorbed by aromatic hydrocarbons. The results also indicate that the surface of 50% methyl⁃modified particles is not only more conducive to the stable adsorption of POA molecules, but also conducive to POA molecules to form a better adsorption configuration. What’ more, on the surface of 50% methyl⁃modified particles, the interaction between POA molecule and C ₂₄H ₅₀ molecules is stronger, and the distribution of C ₂₄H ₅₀ molecules is more aggregated. Finally, the study of this paper provides a method for studying the mechanism of pour point depressants composed of polymer and inorganic nanoparticle and provides theoretical guidance for the experimental modification of nanometer particles in nano⁃hybrid pour point depressant.

Dissolution of CO ₂ in crude oil can change its rheological properties notably, which makes it widely used in the fields of oil displacement, viscosity reduction, transportation and so on. In this study, a pressurized stirring-viscometric equipment was designed based on the stirring viscometry theory, and the corresponding viscometric method was also proposed, so that the viscosity of CO ₂ heavy oil mixture could be determined under the simulation conditions of pipeline transportation. On the basis of this equipment and method, the effects of pressure, shear rate and temperature on the viscosity of CO ₂ heavy oil mixture were probed. It was found that the viscosity of CO ₂ heavy oil mixture decreased exponentially with the increase of pressure. The viscosity of heavy oil system can be greatly reduced by dissolving gas pressure of 2 MPa. Meanwhile, the shear thinning feature became more obvious with increasing pressure of CO ₂. Moreover, the viscosity reducing rate became greater with decreasing temperature at the same pressure. The results of this study provide technical support for the feasibility of transporting viscosity-reduced heavy crude oil by CO ₂.

A dynamic wax deposition model for Jienuo crude oil was established through laboratory wax deposition experiments. With safe operations ensured, taking the sum of average daily power and pigging costs（average daily costs of pipeline operation） as the objective function, a pigging frequency model for unheated oil pipelines was developed. Based on the operation data of Linyi-Zhaozhaizi stations in Linyi-Puyang pipeline, the influence of outlet temperature, throughput and soil temperature on optimized pigging frequency were analyzed. The results show that the average daily costs of pipeline operation will be increased while the pigging frequency will be extended with decreasing of the outlet temperature. The average daily costs of pipeline operation will be increased while the pigging frequency will be shortened with rising of the throughput, and the average daily costs of pipeline operation will be decreased first and then increased while the pigging frequency will be extended with increasing of the soil temperature.

        Given the frequent accidents attributed to abnormal pressure fluctuation and the less effectiveness of preventive measures of complex pipe network, the FTA method of graph theory was applied to solve this problem. Induced mechanism of abnormal pressure fluctuations was interpreted and the FTA model of pressure abnormal fluctuations in complex pipeline network was firstly proposed and established in this paper. An imported crude oil pipe network was taken as a case study by using the Delphi method and fuzzy mathematics theory to solve the model. Results agree well with the actual statistics. Then K-means clustering method was carried on to analyze the three importance of typical basic events and the three-tier structure of the abnormal fluctuations is proposed using the DTA method, which lies a theoretical basis for the analysis on abnormal events as well as the optimization of the prevention and control measures. This paper mainly offers a new research idea in the field of operation security and integrity management of the large, complex pipe network especially when the historical data is far from complete.

It is difficult to manage gathering & transportation pipelines because of their complicate operating conditions. Based on the Chuanping 4623 gathering & transportation pipeline in Changqing oilfield and its operating parameters. The appropriate models, such as flow pattern model, liquid holdup calculation model, pressure drop calculation model and wax deposition model, were selected by comparative analysis. Then, the variation of operating pressure, temperature, liquid holdup, effective inner diameter, gas/liquid superficial velocity and wax deposition rate with pipe distance and operating time was analyzed by programming and calculating the models. The simulating results showed that the wax deposition rate, pressure, temperature, liquid superficial velocity and liquid holdup reduced, while gas superficial velocity increased with the increasing of pipeline length (except for the first 60 meters). The wax deposition rate, temperature, gas/liquid superficial velocity increases, the pressure and liquid holdup decreased at the same node with the increase of operating time within 36 operating hours.

The effects of emulsification conditions (including oil/water volume ratio, emulsifier concentration, emulsifying temperature, emulsifying time and stirrer rotation speed) on the rheological properties of heavy oil-in-water emulsions were studied by using polarized-light microscope and control-stress rheometer. The results show that the droplet size and viscosity of heavy oil-in-water emulsions are increased by increasing oil/water volume ratio (1∶9~7∶3); however, when the oil/water volume ratio is high (8∶2), an emulsion inversion (from O/W to W/O) occurs, leading to a sharp increase of emulsion viscosity. With the increase of emulsifier concentration (0.5%~5%), the emulsion droplet size decreases while the emulsion viscosity decreases first, and then increases. When emulsifier concentrations are not reach to 4%, the emulsions are Newtonian fluids; the emulsion changes into non-Newtonian fluid when the emulsifier concentration reaches 5%. The emulsion droplet size and viscosity are decreased by increasing emulsifying temperature (40~70 ℃). When emulsifying temperatures is above 70 ℃, an emulsion inversion occurs due to the invalidation of emulsifier, causing a sharp increase of emulsion viscosity. With the increase of emulsifying time and stirrer rotation speed, the emulsion droplet size decreases while the emulsion viscosity increases. The non-Newtonian characteristics of the emulsions become obvious with increasing emulsifying time and stirrer rotation speed.

Using differential scanning calorimeter （DSC ）， the crystallization abilities of polyacrylate （PA） pour point depressant and waxy crude oils doped/undoped with PA were studied；then the morphology of wax crystals in the waxy crude
oils doped/undoped with PA was investigated through a polarized light microscope and the depressive effect of PA on Changqing and Qinghai waxy crude oils was evaluated by the pour point tests and rheological experiments．The results show that the crystallization ability of PA improved greatly by increasing the alkyl side chain length of PA but kept unchanged with the increase of average molecular weight of PA．The addition of PA can inhibit the wax precipitation and decrease the wax appearance temperature of waxy crude oils．The size of wax crystals become larger and the structure of them become compact after PA addition，leading to the great improvement of the low temperature rheology of waxy crude oils．The depressive effect of PA on waxy crude oils are related to the crude oil composition and the molecular structure of PA．With the increasing of wax content and the fraction of wax with large carbon number， the depressive effect greatly decreased． The average molecular
weight of PA affected its depressive effect by controlling the solubility of PA in waxy crude oils：the solubility of PA in crude oils decreased with increasing the average molecular weight of PA， thus reducing the interactions between waxes and PA molecules and inhibiting the depressive effect of PA．The better matching the alkyl side chain of PA with the carbon number ofwax in crude oils，the better depressive effect of PA．