Petroleum Chemistry最新文献

Different degrees of soil contamination have been generated by oil spills and leaks from storage tanks in refineries and processing facilities, as well as by the on-and-off loading of oil in different depots. In addition to the careless disposal of spent goods (engine oil) on the ground, this also causes environmental degradation of the soil. In the present study, the effect of contamination of sandy soil by gasoline under circular footing was studied. The circular footing is supported by sandy soil that has been polluted with gasoline by mixing the sand with different percent by dry weight with gasoline (10, 15, and 20%). The contaminated soil is extended to a depth of D/2 and D (where D is the footing diameter). The findings revealed that if the underlying sand is polluted with gasoline, the carrying capacity of the foundation reduces notably. The decline in bearing capacity was found to be 65.6, 59.4, and 51.3% for the sand’s percentages of contamination (10, 15, and 20%), respectively, at the depth of contamination D/2. The reduction in carrying capacity had been discovered to be 70, 78.7, and 33.1% for the depth of contamination D and for the percentages of contamination in the used sand 10, 15, and 20%. respectively. When the depth of contamination is raised from D/2 to D, the carrying capacity decreases by roughly 5–20% for the same percentage of pollution.

Biochar is the result of biomass thermochemical combustion. Biochar production, while characteristic, is highly dependent on the parameters of the production process and the technology used. This study shows that the formation of biochar through torrefaction processes, because of its wide availability of feedstocks and attractive physio-chemical surface qualities, has a significant promise of being employed as a worldwide applicable substance to remediate soil. This research emphasizes biochar manufacturing and its properties and capacity to immobilize and eliminate total petroleum hydrocarbon (TPH) in Soil. The efficacy of biochar in handling pollutants depends upon ion exchange capacity, surface characterization, and pore sizing distribution. The molecule’s texture and biochar’s physics composition could be critical when utilized virtually in the soil. In this study manufacturer biochar at low temperatures to remove polar organic and inorganic contaminants via oxygen-containing functional groups, precipitation, and electrostatic attraction. Additionally, the research investigates the influence of oil pollutants on soil properties and uses biochar to treat the soil that TPH contaminates. Samples are collected from different locations of the Biji refinery and classified according to USCS as poorly graded sand of no plasticity (pL). The contaminant is crude oil disposed of as spills oil from the pipeline and as waste collected in the Noory channel. The soil samples were manually combined with biochar and mixed occasionally to permit the chemical reactivity of contaminant soil and biochar. To know the influence of TPH on specific soil sample attributes and the capacity of biochar to treat TPH throughout the research period (7 months), several testing procedures are performed on both clean and contaminated soil samples. The test indicated that the TPH affects the physical characteristics of soil. The particle size distribution and liquid limit slightly decrease as the contamination percentage increases. On the other hand, the results show significant impact of biochar in cracking the bond of the TPH, degradation percentage was 18.2, 28.62, 36, 50.67, 60.66, 73.33, and 87.24% for spill samples and 17.95, 24.43, 33.35, 46.82, 55.53, 66.65, and 82.24% for Noory channel samples, which indicates that the ability of biochar treatment for spill samples is greater than that of Noory channel samples because of the high concentration for the last.

The current study focuses on reducing heavy crude oil viscosity using a dilution technique with dispersed nanoparticles to create nanofluids in a solvent. The iron oxide NPs used in this study were obtained by a green synthesis using corn husk extract as a biomass source. Biosynthesized Fe₃O₄ Magnetic Nanoparticles (MNPs) were characterized using various techniques, such as XRD, FTIR, SEM and EDX, and then blended with xylene to prepare nanofluids for evaluating their viscosity-reducing performance. Nanofluids were prepared at 298 K using 15 wt % xylene and varying concentrations of Fe₃O₄ MNPs (10, 100, 500, and 1000 ppm). Viscosity measurements were performed at 298 K, over the shear rate range of 2‒42 s^–1 showing that the most significant viscosity reduction (71.3%) in heavy oil samples supplemented with 15 wt % xylene and 1000 ppm NPs occurred at the share rate of 42 s^–1. The effect of temperature on viscosity has been also studied at different T values (298.15, 308.15, and 318.15 K). The most significant reduction (79.79%) of the viscosity of nanofluids (15 wt % xylene, 1000 ppm NPs) was observed at a shear rate of 42 s^–1 and 318.13 K. The results demonstrated a potential of nanofluids as successful and sustainable fluids capable of improving the mobility of heavy oil in transportation pipelines.

A research area that has received limited attention is understanding how the physical properties of nano-carbon materials influence the final application of asphalt binder. Depending on the specific characteristics of the asphalt binder being studied, this research aims to determine whether nano-carbon (NC) can modify the asphalt binder. A penetration-grade asphalt cement with a 60/70 ratio was prepared with nano-carbon (2, 4, and 6 wt %). First, the properties of the asphalt cement and nano-carbon were examined. The NC-modified asphalt binder was then prepared for testing by heating it to 160°C and mixing with a shear mixer running at 2000 rpm for 30 min. The study also measured the Brookfield rotational viscosity, ductility, and softening point temperature of the NC-modified asphalt binder. Increasing the nano-carbon content altered the rheological properties of the asphalt, increasing stiffness and reducing temperature sensitivity. The addition of 4% NC improved the asphalt binder’s fundamental properties, making it suitable for use in hot climates. Incorporating 4% NC into the hot recycled asphalt mixture resulted in a 32.15% increase in Marshall stability, a 21.42% reduction in flow, preservation of unit weight, and acceptable ranges for air voids and other mix properties. Additionally, the indirect tensile strength (ITS) increased by 37.81%. Overall, adding NC to asphalt mixtures generally enhances their properties, particularly improving rutting resistance at high temperatures by reducing rutting depth by 74% at 60°C.

This study compares Pd/Al₂O₃ and Pd₁Ag₅/Al₂O₃ catalysts for the front-end selective hydrogenation of acetylene, with a focus on how their catalytic performance correlates with the H₂ : C₂H₂ ratio and CO concentration. A combination of physicochemical characterization methods demonstrated that single-atom Pd₁ sites isolated from one another by Ag atoms were formed on the surface of the bimetallic sample. The acetylene hydrogenation rate increased with the H₂:C₂H₂ ratio, a correlation that was more pronounced for Pd/Al₂O₃ than for Pd₁Ag₅/Al₂O₃. This was quantified by the apparent reaction order with respect to hydrogen (n(H₂)), which was 1.5 and 1.0, respectively. While increasing the H₂ : C₂H₂ ratio had a significant adverse impact on selectivity toward the target product, this was effectively counteracted by the addition of CO to the reaction mixture. Furthermore, promoting the Pd/Al₂O₃ catalyst with Ag eliminated any thermal runaway effect and facilitated precise temperature control.

The study compares the catalytic performance of two Ni–Mo sulfide systems: a dispersed (unsupported) catalyst and one supported on MCM–41 ordered mesoporous silica. The catalytic performance was evaluated in the hydrotransformation of dibenzothiophene (DBT) using a batch reactor at temperatures of 340–380°C and a hydrogen pressure of 5 MPa for 0.5–10 h. For each catalyst, the apparent reaction rate constant and activation energy were calculated, and the effects of temperature and reaction time on product distribution and selectivity towards the hydrogenation reaction route and direct hydrodesulfurization pathway were determined. The primary products of DBT conversion were biphenyl and cyclohexylbenzene. The dispersed catalyst demonstrated a higher activity for the DBT conversion than its supported counterpart. Furthermore, for the dispersed catalyst, with increasing temperature and reaction time, the dibenzothiophene hydrogenation pathway becomes dominant over the hydrodesulfurization reaction route. In contrast, the MCM-41-supported sample maintained a consistent balance between the two pathways under all tested conditions.

This paper describes the preparation of two bifunctional Pt catalysts: one supported on a ZSM-23 zeolite (MTT topology) synthesized via a seed-assisted method, and the other on a commercial ZSM-23. Physicochemical characterization (XRD, XRF, SEM, TEM, N₂ physisorption, NH₃-TPD) revealed that the synthesized ZSM-23 possessed a hierarchical structure and a balanced distribution of weak and strong acid sites. In n-hexadecane hydroisomerization, the catalyst based on the synthesized ZSM-23 exhibited superior stability (500 h). In the hydroisodewaxing of a hydrotreated diesel fraction, both catalysts provided similar levels of product quality, achieving a dramatic improvement in cold filter plugging point (CFPP of –46 and –47°C vs. –5°C in the feedstock) and high diesel fuel yields (93.4 and 93.1 wt %). The resulting diesel fuel met all specifications (including CFPP, closed-cup flash point, fractional composition, and density) for GOST R 55475-2013 A-44 grade.

High-performance filtration reducers for saturated brine drilling fluids present a novel alternative for drilling anhydrite and mudstone formations, ensuring operational safety and cost efficiency. Conventional filtration reducers are often limited by poor biotoxicity, necessitating the development of environmentally friendly alternatives. In this study, a novel melamine resin-based filtration reducer (MHAN) has been synthesized, exhibiting exceptional thermal stability (up to 302°C). The addition of 3.0 wt % MHAN has reduced the filtration volume of a saturated brine bentonite-based drilling fluid from 162.2 to 8.2 mL and decreased the filter cake thickness from 3.2 to 0.8 mm demonstrating an excellent filtration control. After aging at 200°C, the saturated brine drilling fluid system containing 5.0 wt % MHAN with a density of 2.3 g/cm³ maintains stable rheology and filtration control performance. Notably, MHAN is sulfur-free and exhibits high environmental compatibility, with an LC₅₀ value of 78,500 mg/L. This eco-friendly melamine resin effectively controls filtration loss in saturated brine drilling fluids, supporting sustainable development of oil and gas resources.

This study investigates the effects of modifying ZSM-5 zeolites with iron and manganese via ion exchange. It focuses on how this modification alters the physicochemical properties of the zeolites and influences the conversion pathway of a n-dodecane/2-methylthiophene (5000 ppm S) feedstock in catalytic cracking. For all modified zeolites, which had SiO₂/Al₂O₃ ratios of 23 and 80 and metal loadings up to 1.94 wt %, the decrease in micropore volume and specific surface area did not exceed the margin of error. The modification of ZSM-5 with either Fe or Mn led to significant improvements, with the SiO₂/Al₂O₃ playing a key role. Acidity, confirmed by NH₃-TPD measurements and quantum-chemical (DFT) simulations, increased in concentration (by 89%) and strength for the zeolite with SiO₂/Al₂O₃ = 23. Catalytic performance was enhanced with both modifier metals and for both zeolites, but more profoundly for the SiO₂/Al₂O₃ = 23 variant: the yield of light olefins increased by 45% (compared to 26% for the SiO₂/Al₂O₃ = 80 zeolite), while the sulfur content in liquid products was reduced by 46% (compared to 33%).

The study investigates the effects of byproduct water from ethanol self-condensation on the performance of a 2%Cu/γ-Al₂O₃ catalyst. It was found that water accumulation in the reaction mixture inhibits the self-condensation of ethanol into linear primary alcohols (1-butanol, 1-hexanol, and 1-octanol). XRD and NH₃-TPD characterization revealed that 12 h of operation reduced the overall catalyst acidity and caused partial phase transition from γ-Al₂O₃ to boehmite, both effects likely caused by contact with water produced during the reaction. SEM and IR spectroscopy demonstrated structural changes in the catalyst surface. The yield of linear primary alcohols increased through the use of dehydrated ethanol or the addition of potassium carbonate to bind the water produced.