To address the corrosion failure issues in hydrogenation reaction effluent air cooler (REAC)systems, a typical process simulation model was constructed using the reverse order deduction method. This study investigated the influence mechanisms of different oil flow rates on the distribution of corrosive components within the system, ammonium salt crystallization temperature, and erosion risks. The results indicate that variations in oil flow rate do not significantly affect the aqueous distribution of corrosive components or increase the system's erosion risk. Additionally, the oil flow rate has minimal impact on the crystallization temperature of ammonium salts, meaning higher flow rates do not elevate the risk of salt formation. However, increasing the flow rate of vacuum gas oil (VGO) markedly reduces the corrosion factor (K), thereby lowering the overall corrosion risk. The VGO flow rate also has a pronounced influence on the aqueous NH?HS concentration at the air cooler outlet, whereas the effect of naphtha flow rate differs from that of diesel and VGO. Notably, raising the flow rates of diesel and naphtha increases the system pH, while increasing VGO flow rate decreases it. To mitigate corrosion risks, it is recommended to moderately increase the VGO content during crude oil processing while simultaneously boosting either the diesel content or injection water volume.
Under solvothermal conditions,Cu（CF3COO）2·xH2O was used as a soluble copper salt, and thiophene?2,5?dicarboxylic acid （H2tdc） as a linear ligand, which reacted with 1,10?phenanthroline （phen） and 2,2′?bipyridine （bipy） respectively,to synthesize two one?dimensional chain compounds:[Cu（tdc）（phen）] n （1） and [Cu（tdc）（bipy）] n ·DMF （2）.The structures of the synthesized compounds were characterized by single?crystal X?ray diffraction（SC?XRD）.The compositions of the compounds were analyzed by polycrystalline X?ray diffraction and Fourier infrared spectroscopy.The performances of the compounds were studied through photocurrent response tests and solution stability tests.The results show that the asymmetric structural unit of compound 1 is extremely similar to that of compound 2,with both containing the same [Cu(tdc)] structural unit. Both compounds exhibit photochemical stability,but they show different photocurrent response values,which is attributed to the different surface?modifying ligands (phen and bipy) in the two compounds.
To address the issue of high steam consumption in the propane removal tower of the three tower gas fractionation process in refineries, it is proposed to use a high and low pressure dual tower propane removal process instead of the single tower propane removal process in the original process. The process was simulated under steady?state conditions using Unisim Design process simulation software. The steam load of the high?pressure depropanizer and the hot water load of the deethanizer were analyzed, and the main operating parameters were optimized. The results showed that under the operating conditions of n(top C3 production)/n(total feed C3)=0.6, top pressure of 1.81 MPa, feed tray position of the 10th plate, and feed positions of the 114th and 126th plates at the top of the propane removal tower and low?pressure propane removal tower respectively, using the high and low?pressure double tower propane removal process can save 56.12% of steam load compared to the original process, save 49.83% of hot water load in the ethane removal tower compared to before optimization, reduce total energy consumption by 235.4 kW, and save about 339.71 yuan in thermal utility costs per hour.
Carbon dioxide capture,utilization and storage(CCUS) is a crucial strategy for mitigating the greenhouse effect and reducing CO? emissions.As the predominant technology for large?scale commercial CO? capture,the high energy consumption of the absorption method seriously restricts the popularization and development of CCUS technology.This paper focuses on the energy?saving path in the CCUS process,and systematically reviews the latest research progress and achievements in three key directions: The research and development of new absorbents,design of new high?efficiency reactors,coupling of CO2 capture and conversion process.The results show that the new absorbent reduces the energy consumption of the absorption reaction process,the high?efficiency reactor greatly enhances the mass transfer,and the integrated coupling technology realizes energy saving and consumption reduction from the process source.Future research needs to focus on the verification of the industrial application of new absorbents,the stability and cost control of long?term operation of reactors,and the further improvement of the economic efficiency of absorption and conversion integration technology,so as to promote the large?scale application of low?energy CCUS technology and help achieve the "double carbon" goal.
In order to quickly define the dangerous distance of leakage in hydrogen?blended natural gas high?pressure pipelines, this study established a mathematical model of small hole jet leakage of hydrogen?blended natural gas high?pressure pipelines in open space by integrating the pipeline leakage model,nominal nozzle model and jet in cross?flow integration model,verified the applicability of the jet in cross?flow integration model under high?speed jet and analyzed the influence of hydrogen ratio,wind speed leakage hole diameter and pipeline pressure on the leakage jet trajectory and the influence of hydrogen ratio,wind speed and nominal diameter on the maximum explosion danger distance.The results shows that the JICF model is in good agreement with the experimental data and the numerical simulation data.The greater the hydrogen mixing ratio,the diameter of the leakage hole and the pipeline pressure are,the less the deflection degree of the leakage jet trajectory will be.The higher the wind speed is,the greater the deflection degree of the leakage jet will be.The relationship between the hydrogen ratio and the maximum dangerous explosion distance decreases linearly when the hydrogen ratio is lower than 44.4%,and increases linearly when the hydrogen ratio is higher than 44.4%.The relationship between the wind speed and the maximum dangerous explosion distance is approximately linear.The nominal diameter is directly proportional to the maximum explosive danger distance.
Improper models of phase behavior are a major cause of many production problems faced by shale gas reservoirs. The phase behavior of oil?gas in micro?nano pores is crucial for shale oil and gas development. Considering the effects of capillary pressure and critical point shift on the thermodynamic phase equilibrium in micro?nano pores, a vapor?liquid equilibrium (VLE) model in the confined micro?nano pores was developed by using a volume?translated Peng?Robinson Equation of State(PR?EOS), and the relative error of prediction was less than 1.53%. Based on the improved VLE model, the phase behavior of hydrocarbon mixtures such as Bakken shale oil in the confined space was investigated. Results indicate that the nanopore confinement decreases the vapor?liquid density difference and equilibrium coefficient(K) of the light components and shrinks the phase envelope. As the pore size decreases, the interfacial tension (IFT) first decreases slowly and then drops sharply, particularly when the pore radius is less than 20 nm.This study can provide an important theoretical foundation to support the development of unconventional oil?gas resources.
In the process of heavy oil thermal recovery using SAGD (Steam?Assisted Gravity Drainage) technology, conventional thermal recovery boilers are mainly used for heat generation. When steam is used as the heat?carrying medium, problems such as a short water breakthrough time and low heat utilization efficiency are often encountered, resulting in low oil recovery. Changing the heat generation method to reduce water injection while ensuring heat injection is of great significance for thermal recovery.Based on the analysis of directional chemical reaction products and combined with large?scale three?dimensional physical simulation experiments, the feasibility of directional chemical reactions was verified, the expansion law of the temperature field in directional chemical reaction?assisted SAGD was clarified, and the characteristics of production curves at different mining stages were analyzed and evaluated.The results show that among the products of the directional chemical reaction, the liquid fluid is mainly C5-C20, and the gaseous substances are mainly CH4 and CO2; the final recovery degree of SAGD development assisted by directional chemical reaction products is 76.59%, which is 19.99 percentage points higher than that of pure SAGD. The research further verifies the mechanism of the directional chemical reaction?assisted SAGD efficiency?increasing technology, providing a theoretical basis and technical support for field applications.
To address the lack of specialized thermal?hydraulic calculation models for temperature?resistant polyethylene pipelines in oilfield gathering and transportation systems,this study conducted quantitative analysis on their hydraulic friction characteristics and thermal temperature drop patterns during oil transportation through field experiments.Based on multi?parameter experimental datasets,systematic investigations were performed to reveal the influence mechanisms of key variables including fluid properties, transportation temperature,rate of water content,and flow rate on pipeline pressure drop and temperature decline.For the first time,a calculation framework for the overall heat transfer coefficient applicable to temperature?resistant polyethylene (TRPE ) materials was established.Simulation model libraries were constructed using PIPEPHASE software,followed by comparative analysis of deviations between theoretical predictions and field measurements under varying boundary conditions.Through this process, friction calculation models and heat conduction models tailored for TRPE materials were selected and optimized,which provide valuable theoretical support for the process design and safety evaluation of TRPE pipelines in engineering applications.
For the reaction of catalytic dehydrogenation of ethanol to produce acetaldehyde, current catalysts face the challenge of limited selectivity, particularly exhibiting poor performance in the efficient generation of acetaldehyde. Some catalysts are hindered in the dehydrogenation process due to excessive acidity, which urgently needs to be addressed. Therefore, the development of novel catalysts with high?performance surface basicity is crucial.Two composite catalysts, La2O2CO3/ZnO?a and La2O2CO3/ZnO?b, were prepared using the co?precipitation method and the solution combustion method. The performance of the catalysts was evaluated by varying preparation conditions such as precipitation pH, aging time, calcination temperature, and calcination time to determine the optimal synthesis parameters. Advanced characterization techniques, including Scanning Electron Microscopy, Transmission Electron Microscopy, X?ray Diffraction, and CO2 Temperature?Programmed Desorption, were employed to thoroughly investigate the catalyst's crystal phase, morphology, surface basicity, and their relationship with catalytic performance. The optimal process conditions for ethanol dehydrogenation to acetaldehyde were investigated on the best?performing catalyst. When the precipitation pH was 9.0, the aging time was 12.0 h, the ratio of nLa to nZn was 1.0, and the calcination temperature was 600 ℃, the optimal preparation conditions for the solution calcination method were determined as follows: calcination time of 5.0 h, calcination temperature of 550 ℃, and nLa/nZn of 1.0. Under the conditions of a volume space velocity of 1.0 h?1, a reaction pressure of 1.0 MPa, and a reaction temperature of 190 ℃, La?O?CO?/ZnO?a achieved the highest acetaldehyde yield of 57.60%.
With the development of industrialization and modernization, water pollution has become increasingly serious, and the use of sunlight for water pollution degradation has become a future development trend. In this paper, flower?like BiOI photocatalyst was prepared via a solution route at room temperature without any template, and characterized by X?ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and UV?Vis diffuse reflectance spectra (UV?Vis DRS). As?synthesized flower?like BiOI showed better visible light photocatalytic activity for degrading Rhodamine B (RhB) than TiO2. The experimental results of active species and electron spin resonance (ESR) measurement showed that ·O
