Petroleum Chemistry最新文献

Hierarchical Al-BEA zeolites were prepared by hydrothermal treatment of the reaction mixture containing highly dispersed Aerosil A-300 as a silicon source without alkali metal cations and additional templates for the mesopore formation. The material with the most developed mesoporosity is formed by concentrating the reaction mixture to the H₂O/Si molar ratio of 5.5. The catalytic properties of the hierarchical materials prepared and commercial zeolite in benzene alkylation with propylene were studied. The samples tested exhibit 88–91 wt % cumene formation selectivity. The hierarchical zeolite prepared from the reaction mixture with the H₂O/Si ratio of 5.5 ensures the highest propylene conversion and exhibits the highest stability in alkylation. This zeolite has the highest mesopore volume, the highest external specific surface area, high concentration of strong Brønsted acid sites, and relatively low content of Lewis acid sites.

Density functional theory (DFT) is the most widely used method of chemical calculations of the structure of atoms that has rapidly gained popularity, two groups of pyrimidine ring derivatives were prepared, the first group is 4-(4-aminophenyl-6-phenyl)pyrimidin-2(1H)-one derivative by adding groups (‒NO₂, ‒Cl, ‒Br, ‒OH), and the second group 4-(4-aminophenyl-6-phenyl)pyrimidin-2(1H)-thione derivatives adding the same groups to study the inhibition efficiency of corrosion, these results show were able to find the theoretically calculated inhibition efficiency value that will increase or decrease the inhibition efficiency, the inhibition efficiency of pyrimidine-1 was measured to make it standard for 4-(4-aminophenyl-6-phenyl)pyrimidin-2(1H)-one derivatives, the inhibition efficiency was improved to (80.962%) as in pyrimidine-4. For 4-(4-aminophenyl-6-phenyl)pyrimidin-2(1H)-thione derivatives, the inhibition efficiency of pyrimidine-6 was measured to make it standard for these derivatives, and the inhibition efficiency was set to (83.838%) for pyrimidine-8. which reinforces that the presence of the hydroxyl group among the groups (nitro-, chloro-, bromo-) was the best in improving the inhibition efficiency of the derivatives of pyrimidine derivatives.

Wastewater usually is treated by using a variety of physical, chemical and biological methods to remove phosphorus and nitrogen from it. This paper examined an experimental investigation to assess the removal of nutrients from synthetic wastewater using a lab-scale Bardenpho process. This study aims to address the impact of hydraulic retention time (HRT) on the nutrients removal efficiency at various internal recycle ratio by using enhanced Bardenpho process. A modified Bardenpho process consists of five reactors (anaerobic, first anoxic, first aerobic, second anoxic, second aerobic) with a secondary settling tank to separate the biomass before to discharge in order to accomplish significant nitrogen and phosphorus removal. The nitrate was recycled into the first anoxic chamber (IR 1), first aerobic chamber (IR 2), and second anoxic chamber (IR 3) in that order after oxidizing in the aeration chamber. Hydraulic retention time of 9.5, 13.5 and 17.5 h were shown to have an effect on the biological reduction of nitrogen and phosphorus using enhanced Bardenpho process. Inlet chemical oxygen demand (COD), total nitrogen (TN), and PO₄ concentrations of 413, 35, and 15 mg/L, respectively, were used to operate at each hydraulic retention time. The HRT of 17.5 h and IR 1 attended maximum removal efficiency of 77.86% for TN at IR 1 and aerobic/anoxic ratio ratio of 1.65, and 68.33% for TP at IR 1 and aerobic/anoxic ratio of 2. While the highest elimination efficiency for COD was 94.92% at IR 1 and total HRT of 17.5 h when the aerobic/anoxic ratio ratio is 2.

This study explores the potential of vacuum residue (VR) as an unconventional and renewable source of global transportation fuel. The primary aim is to investigate the cracking of Iraqi VR using an economically feasible and environmentally friendly geopolymer catalyst. Two types of metakaolin, red (designated G1) and white (designated G2), were mixed with alkaline activators to synthesize geopolymers with a hierarchically porous structure (containing interconnected pores of varying sizes). Following synthesis, the geopolymers were subjected to activation through hydrochloric acid (HCl) treatment. Finally, thermal treatment at 750°C for 2 h was applied to the geopolymer powders. This process yielded red kaolin-based geopolymer G1* and white kaolin-based geopolymer G2*. The extensively characterized using various techniques including XRF, XRD, FE-SEM, FTIR, and BET. Significant differences in Si/Al ratios and iron content were observed between the red and white geopolymers. The white geopolymer showed annite-1M phase, while the red geopolymer showed the existence of a zeolite phase, according to XRD analysis. Further investigation using an FE-SEM revealed that both materials had uniformly distributed, different amorphous morphologies. BET analysis subsequently revealed significant differences in surface area between the red geopolymers (60.89 m²/g) and white geopolymers (19.42 m²/g). Cracking the vacuum residual involved utilizing a geopolymer catalyst within a fixed-bed reactor. The resulting hydrocarbon liquid product, collected to a volume of 17 mL, underwent analysis using Gas Chromatography-Mass Spectrometry (GC-MS). The analytical results obtained from GC-MS provide strong evidence for the effectiveness of the white geopolymer catalyst in the conversion of vacuum residue and producing light petroleum fractions. Notably, the white geopolymer catalysts generated 47% more gasoline products than the 30% yield achieved with red geopolymer catalysts. The vacuum residue obtained from the Al-Doura petroleum refinery in Baghdad, Iraq, exhibited a waxy texture, and black color, and contained heavy hydrocarbons with high molecular weights. This residue is known as Doura Vacuum Residue (VR). Interestingly, the red geopolymer catalysts produced gasoline products of higher quality.

Novel pyrazoles namely 1-(3-(4-hydroxyphenyl)-5-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-1-yl)ethanone (HTPE) and 4-(5-(thiophen-2-yl)-4,5-dihydro-1H-pyrazol-3-yl) aniline (TPA) was synthesized from the condensation of chalcone derivatives with hydrazine hydrates, and their inhibitive characteristics for the corrosion of mild steel in 0.5 M hydrochloric acid solution were investigated to both chalcons and pyrazoles compounds by electrochemical method, and the scanning electron microscopy (SEM). The result shows the chalcone compound (ATP) has been essential in preventing mild steel corrosion in an acidic solution.

The study presents the development of a novel magnetic g-C₃N₄/MXene nano-photocatalyst for the efficient removal of pharmaceutical azithromycin from real wastewater. The escalating levels of pharmaceutical pollutants, particularly azithromycin, necessitate robust removal techniques. Photocatalysis, known for its affordability and eco-friendliness, is explored here, focusing on combining g-C₃N₄ with 2D MXene, offering stability, light absorption, and magnetic properties. The synthesis and characterization methods confirm the structural integrity and successful production of the nano-photocatalyst. High-performance liquid chromatography measures azithromycin levels in actual wastewater. Under sunlight exposure, the nano-photocatalyst exhibits exceptional photodegradation, removing 94% of azithromycin in just 120 min. Kinetic studies reveal pseudo-second-order kinetics and significant organic carbon removal efficiency exceeding 85% in less than 90 min is observed. Overall, the research highlights the potential of the magnetic g-C₃N₄/MXene nano-photocatalyst for sustainable and effective pharmaceutical contaminant remediation, positioning it as a promising solution for water treatment processes.

A five factor, three-level Central composite design (CCD) combining with response surface (RSM) was employed for maximizing crystal violet adsorption capacity (q_e) and removal dye from aqueous solution using a low-cost biosorbent prepared from a 50 : 50 mixture of two microalgae species: green (Chlorella vulgaris) and blue-green (Arthrospira platensis). The biosorbent was characterized by Fourier-transform infrared spectroscopy (FT-IR). Central composite design within response surface methodology (RSM) was employed to optimize five critical factors affecting crystal violet (CV) removal: pH 3‒11, biosorbent dose 250‒750 mg, temperature 20‒50°C, initial CV concentration 10‒30 ppm, and adsorption time 5‒15 min. MINITAB 18 software was used to maximize the adsorption capacity. The highest experimental crystal violet dye capacity of 140 mg/g was found in the lowest algae dose, consistent with calculated values based on numerical optimization. Kinetic modeling revealed the best fit with the pseudo-first-order model R² (0.9829), while equilibrium isotherm data were best described by the Langmuir model R² (0.9960). Thermodynamic parameters (ΔG⁰, ΔH⁰, and ΔS⁰) indicated the spontaneity and endothermic nature of the biosorption process. Finally, the study of mass transfer adsorption models was examined using the Weber and Morris model, the liquid film diffusion model, and Bangham and Burt’s model. When comparing these models, Bangham’s and Burt’s model has the highest R² (0.9971). The rapid dye uptake suggests the potential of this algal biosorbent for efficient and simultaneous dye removal in real-world contaminated environments.

Removal of sulfur compounds from middle distillates by hydrotreating is challenging, while their oxidative removal is promising. In this study, the oxidation of dibenzothiophene (DBT), 4-MDBT, and 4,6-DMDBT in a model fuel to form the corresponding sulfones has been carried out using cumene hydroperoxide as an oxidant over a MoO₃/γ-AlO₃ catalyst. Then the adsorptive removal of DBT-sulfone from a model fuel over different adsorbents has been performed. Finally, an integration of oxidation and adsorption processes for the removal of refractory sulfur compounds from a hydrotreated middle distillate has been successfully demonstrated. The DBTs have been effortlessly converted to the corresponding sulfones. However, the activity of the catalyst during this process decreases significantly due to the sulfone adsorption on the surface of a catalyst. Various tested adsorbents have shown two different adsorption isotherms for removing DBT-sulfone depending on their different textural structures and adsorption mechanisms. The best adsorption capacity in an equilibrium sulfur concentration range of less than 10 ppmw has been provided by a zeolite adsorbent, whereas alumina adsorbents show a higher adsorption capacity in an equilibrium concentration exceeding 15 ppmw due to the multimolecular adsorption within the pores with a diameter of ~40 Å. Integration of oxidation and adsorption processes is promising for removing refractory sulfur compounds from hydrotreated middle distillate.

The enhanced anti-friction performance of novel additives derived from industrial olefin-rich naphtha (IORN) for ultra-low sulfur diesel (ULSD) has been reported in this study. Initially, IORN has been maleated with maleic anhydride in a pressure reactor to obtain alkenyl succinic anhydride (ASA). The ASA has been then esterified using various alcohols containing C₂ to C₁₆ alkyl chains to obtain a mixture of diesters. The friction-reducing capability of the diester blend in ULSD has been evaluated at different blending concentrations by HFRR. The diester derived from hexadecanol has demonstrated an improved anti-friction performance at a very low blending concentration of 150 ppm. Interestingly this diester exhibits better friction-reducing quality than other reported olefin-based additives.

A series of rac-Et(2-MeInd)₂ZrMe₂/octylaluminum aryloxide catalytic systems were prepared, with octylaluminum aryloxides being represented by (2,6-^tBu₂,4-Me-PhO-)AlOct₂ (Al_1BHT (Oct)), (2,6-^tBu₂PhO-)AlOct₂· (Al_1DTBP (Oct)), (2,6-^tBu₂,4-Me-PhO-)₂AlOct (Al_2-BHT (Oct)), and (2,6-^tBu₂PhO-)₂AlOct (Al_2-DTBP (Oct)). Octylaluminum aryloxides proved to be effective activators of the zirconocene precatalyst in the homo- and copolymerization of olefins. In order to identify the generality and/or specificity of catalyst activation by octylaluminum aryloxides (Al(Oct)), the catalytic performance of the catalytic systems was compared to that of the previously investigated systems activated with isobutylaluminum aryloxides (Al(IBu)). The activator structure was shown to affect the catalytic activity, molecular weight characteristics, copolymer composition, and thermophysical properties of the polymers produced. When compared to isobutylaluminum aryloxides (other conditions being equal), the catalytic systems with octylaluminum aryloxides exhibited a higher activity in homo- and copolymerization (99– 326 kg_polymer mol_Zr^–1 bar^–1) and a higher degree of propylene incorporation into E/P copolymers (up to 26 mol %), but lower molecular weights of the copolymers produced (57–105 kg/mol). The systems activated with isobutylaluminum aryloxides achieved 28–277 kg_polymer mol_Zr^–1 bar^–1, up to 15 mol %, and 92–265 kg/mol, respectively. At the same time, the copolymers produced using Al(Oct) activators had low melting points (91–112°C) and low degrees of crystallinity (9–28%), even in ternary copolymers (terpolymers) with low comonomer content. This is indicative of statistical distribution of comonomer units in macromolecular chains, which limits the formation of extended methylene sequences. The study further provides the results of mechanical tests of the copolymers synthesized using the different activator types. The copolymers obtained with octylaluminum aryloxides exhibited somewhat lower levels of tensile stress (σ = 5–16 MPa) and elongation at break (ε = 100–840%) than the samples synthesized over catalytic systems with isobutylaluminum aryloxides (σ = 5–25 MPa; ε = 400–1050%).