Petroleum Chemistry最新文献

To address the limitations of the existing catalytic hydrogenation and sulfuric acid sulfonation intended to remove aromatic hydrocarbons from liquid paraffin oils, the adsorption method was chosen for the adsorptive separation of phenanthrene, a typical aromatic hydrocarbon, from liquid paraffin oils. A zeolite imidazolate framework-8 (ZIF-8) precursor was firstly prepared, and then ZIF-8-derived porous carbon (ZDPC) adsorbents were obtained using different temperatures of carbonization of the precursor under nitrogen atmosphere; these adsorbents were then used for the adsorption and separation of phenanthrene from liquid paraffin oils. The experiment showed that the maximum specific surface area of a ZDPC adsorbent could reach 1458 m²/g at 900°C. However, the total pore volume and adsorption capacity of ZDPC porous carbon were maximal at the carbonization temperature of 800°C (1.59 cm³/g and 931 mg/g, respectively). The obtained results showed that an increase in the specific surface area of the adsorbent did not necessarily enhance the adsorption performance. However, compared with the specific surface area of the adsorbent, its adsorption performance is improved in the case of larger pore structures. Therefore, the pore structure of the adsorbent has a very important influence on the adsorption performance. The results of kinetic and thermodynamic studies showed that the pseudo-second-order model could better explain the adsorption process of ZDPC on phenanthrene, while the intra-particle diffusion model revealed that the adsorption mechanism represented a continuous three-stage process.

This review summarizes the current advances in the synthesis of polyoxyalkylene ethers and alkyl oxalates. It discusses the prospects for the application of these oxygenates as engine fuels and the methods for their structural modification to ensure effective control of their performance characteristics.

This study aimed to investigate the influence of the content of crystalline (10, 30, 60%) and amorphous (90, 70, 40%) aluminosilicates in the starting granules prepared for the synthesis of hierarchical ZSM-5 zeolite on the physicochemical properties, activity, selectivity, and stability of the resulting materials in the Skraup reaction for quinoline synthesis. As the ZSM-5 content in the parent granules was raised from 10 to 60%, increasing trends were observed for the micropore volume (from 0.10 to 0.13 cm³/g) and mesopore volume (from 0.05 to 0.19 cm³/g) in the granules of the resultant hierarchical zeolites H-ZSM-5_h(10, 30, 60). At the same time, the macropore volume decreased from 0.34 to 0.29 cm³/g. The H-ZSM-5_h(60) sample had the highest concentration of acid sites and exhibited the highest activity and selectivity in the Skraup reaction, as evidenced by 72% yield of quinolines. Moreover, this sample exhibited the highest stability, H-ZSM-5_h(60) remained stable for 9 h, whereas the activity of H-ZSM-5_h(10) and H-ZSM-5_h(30) dropped after 3–4 h.

Abstract

Advanced materials calculations have been recently widely employed. One of these powerful calculations is Density Functional Theory (DFT). In this work, DFT was used to study the methane dissociation over the surface of the transition metal nickel (Ni) with crystal orientation of (111). The favorable configuration for CH₃ molecule was on the top of Ni with adsorption energy of –2.278 eV, while the face-centered cube position was the favorable structure for the hydrogen (H) atom with a –2.713 eV adsorption energy. The estimated reaction rate constant for the dissociation process was 4.801×10^–15 s^–1, and the barrier energies were –0.10664191×10³, –0.10382003×10³, and –0.10616790×10³ eV for initial, transition, and final state respectively. The adsorption types were physisorption for CH₄ and chemisorption for both CH₃ and H on the Ni(111) surface.

Abstract

Fluidized bed reactors are widely used in a variety of chemical industrial processes for extremely exothermic reactions. But the performance of the reactor could be impacted if the exothermic reaction’s heat isn't removed sufficiently. Understanding and analyzing the heat transfer mechanisms occurring in the reactor is crucial to improving the reactor’s overall performance as well as the chemical process. The investigation was carried out in two stages) one tube heater, five internals equipped with one tube heater). In both stages, the heat transfer probe was moved to different places around and inside the center and the range of gas velocity was 0.2–0.48 m/s. A sophisticated heat transfer system was used to investigate locally and instantly how a bundle of vertical heat-exchanging tubes affects the heat transfer coefficient (HTC) in a gas solid fluidized bed. The experiments were conducted on 0.13 m inner diameter Plexiglas fluidized bed reactor by using silica sand as particles with size of 600 µm and fixed packing height 35 cm. The heating element consists of solid brass shell, a heater and flux sensor. The heat transfer probe dimensions 12 mm diameter and 8 cm length. The thermocouples were 10 cm above distributer. The local heat transfer coefficient (LHTC) increase with increasing fluidizing velocity. There is a different behavior of HTC at various local position of tube heater in comparison with other different tubes position. When there are vertical internals present in the center, the HTC increases by 31% for different gas velocities. A comparison of local heat transfer coefficient with internal tube and without internal tube gives a reasonable result.

Abstract

This research is mainly concerned on studying the effects of heating surface area of immersing heater and particles size of bed packing on values of heat transfer coefficient (HTCs) under different air flow rates. Experiments were conducted in a gas-solid fluidized bed to study the steady-state heat transfer between gas and solid, along with the surface of the bed at various velocities, ranging from static bed to fluidized bed conditions (0.024– 0.387 m/s). The bed column was 172 mm in diameter and 1000 mm in height, attached with a horizontal heating tube of different diameters (19.5, 25.4, and 30 mm). Three different sizes of sand particle were employed (i.e. 200, 300 and 400 µm). HTCs are shown to rise with fluidizing air velocity while exhibiting a reverse association with particle size. The influence of heating tube diameter on HTC has been examined with remarkable fluctuations revealing the bed’s hydrodynamic characteristics.

Abstract

Core samples extraction is one of the main processes before routine core analyses. This process consumes time and chemical solvent so, it is necessary to find new techniques and materials to increase the efficiency of extraction method with less time and chemical consumption. The objective of this research project is to use the microwave and nanoparticle-assisted technologies in the extraction of oil in rock samples. The samples of carbonate reservoir rocks used in this research. Microwave heating can be a powerful tool for thermal treatments because many benefits can be achieved as proven by previous research. However, an increase in the efficiency of the nanoparticles assisted microwaves has been demonstrated in the extraction by adding the nano silica with different weight ratios to the solvent used in the experiments and exposing samples to the microwave effect under different powers then comparing the results with that of samples treated with microwave only. The experiments showed that the adding 0.1 wt % of nano silica reduced cleaning time to approximately 70% less than cleaning by using the microwave technique without nano silica; that can refer to the high efficiency of nano silica assistance in rock extraction; Furthermore, the application of multicriteria analysis has been used in the real case and shows that the most important criteria for cleaning efficiency were process control, rock properties and chemical consumption respectively. Also, it was found that the assisted microwave extractor using the toluene solvent—nano silica as a cleaning agent has priority over the other technique for cleaning plug samples.

Abstract

The prediction of catalytic naphtha reforming products is one of the main challenges issues in oil sector. Investigating continues catalytic reforming (CCR) C₅₊, C₁, C₂, C₃, and C₄ are achieved by using response surface methodology (RSM). The process can be described in terms of several controllable variables which are research octane number (RON), naphthenes and aromatics. In present work, a quadratic polynomial equation for Naphtha C₅₊, SCFB H₂ has been obtained by utilizing RSM and the results were tested by design of experiment (DOE) and ANOVA analysis. The experimental results show good agreement with the predicted model with a yield of C₅₊ ranging from 77.27 to 109 when the RON is in the range of 68 to 95, naphthenes (vol %) is in the range of 15 to 25 and aromatics (vol %) is in the range of 10 to 30. H₂ yield varying from 0 to 1.37 is significantly affected by increasing C₅₊ and reduced by decreasing RON. The yield of other products is calculated by multiple regression analysis depending on C₅₊ conversion range 77–100. The yields of other products of reformer (C₁, C₂, C₃, C₄) can be calculated from correlation that developed using multiple regression analysis. This case study indicates that the statistical model is useful of CCR.

Abstract

Water in oil emulsion is considered as a serious problem in petroleum sector, it impacts both production costs and environmental restrictions. The presence of emulsions in crude oil will lower the quality of the crude itself, increase operating costs due to emulsions separation, cause corrosion to the transport system, and contaminate catalyst used in the refining process. Emulsions formation in the pipeline is undesirable because emulsions will cause negative impact or quandaries to the field. The most common techniques for water—oil separation is using of an electric field with inorganic salts in a demulsification process. In the present work, a new green technique depends on electromagnetic waves of microwave irradiation was accomplished to achieve the separation without using any chemicals. The experimental part utilized a microwave reactor the emulsions were prepared in a concentration of water to oil was 40 vol % two operating variables were utilized as follow: power 200–1000 W and time 40–200 s. The experiments were designed by using central composite rotatable design method with two variables. A Statistical software was utilized to achieve the optimization process to obtain the optimum conditions. The results showed that the optimum separation was produced at 800–900 W power and 150–200 s of treatment time. It was proved that microwave technique is considered as cost effective and environmental friendly technique. And it shows the capability of microwave technology for enhance the demulsification of water-oil emulsion in a short time.

Abstract

To improve the design and scale-up processes of bubble column reactors (BCRs), it is necessary to characterize the hydrodynamics by means of flow regime behavior. This study examines the impact of industrial heat exchangers and superficial gas velocities on flow regimes, pressure drop, and gas holdup in BC and SBC. A simulated Fischer–Tropsch bubble column is constructed. The experimental study utilized a Perspex column with a diameter of 0.14 m. Moreover, 18 copper tubes with a 0.16 m diameter are fitted into the bubble column. The selection of tubes in SBC was carried out in accordance with TEMA recommendations to ensure optimal heat dissipation. These tubes were made to resemble the industrial Fischer–Tropsch reactor by covering 25% of the bubble column’s cross-sectional area. In order to enhance the measurement and comprehension of the hydrodynamics within the reactor, this study employs a method measured the total gas hold-up and detected pressure fluctuations using three differential pressure transducers (Keller type PA 21Y/4). The column was equipped with a perforated plate air distributor, and glass beads were used as the solid phase. The gas distributor is constructed of porous polyethylene with pore sizes of 0.5 mm and plate thicknesses of 3 mm. To comprehend and assess the impact of tube configuration on the pressure drop; gas holdup; and regime transition velocities, the experimental data were recorded across a broad range of superficial gas velocities (i.e., 0.036–0.27 m/s). The findings suggest that higher superficial gas velocities result in amplified pressure fluctuations, with a recorded increase of 0.108 to 0.15 bar in pressure drop at a gas velocity of 0.27 m/s in the air-water system. Equipping the bubble/slurry bubble column with an industrial heat exchanger to the bubble/slurry bubble column resulted in a modest increase in pressure drop of around 0.042 bar, which disrupted the uniform flow and delayed regime transitions. Furthermore, the inclusion of solids leads to a 10% decrease in gas holdup, while the heat exchanger only slightly improves it by 5%. Drift flux analysis is a helpful tool for determining transition points. In the case of U-shaped heat exchanger tubes, the transition velocities can be altered by 1.7 m/s in BC. The results of this investigation will offer an exhaustive understanding of fluid dynamics as well as guidance in the design of reactors for extremely exothermic processes.