Petroleum Chemistry最新文献

This study investigates the effects of introducing a feedstock-soluble catalyst based on iron salts of petroleum acids on the oxidation of crude oil vacuum residue (VR) to produce commercial bitumen. It is demonstrated that, compared to noncatalytic VR oxidation, injecting the catalyst into the petroleum feedstock provides a higher process efficiency (indicated by more than double the oxidation rate) with the bitumen product being distinguished by enhanced thermal stability and a higher ductility (>100 cm). IR spectroscopy showed a difference in the structural-group composition between the initial VR and the oxidation product, specifically an aromaticity increase and the formation of polysubstituted aromatics in the oxidate. Due to the acceleration of the oxidation process and the improvement of the product quality, the catalytic oxidation of VR provides a high potential for the implementation of this process strategy at industrial oil refineries. Furthermore, this approach can be recommended as the optimal available technique for mitigating the anthropogenic environmental impact.

The study investigates, for the first time, the effects of the composition of a catalytic dispersion on its performance in three-phase hydrogenation of a CO+CO₂ mixture in a continuous stirred-tank slurry reactor (CSTR) without pre-separating the feed mixture. It is shown that the selectivity towards specific hydrogenation products can be controlled by varying the choice of nature of the metal of nanosized dispersions. Specifically, Co- and Fe-based dispersions mainly promote the production of C₂₊ hydrocarbons, and Ni-based samples lead to the predominance of methane in the products.

A series of catalysts were prepared from a granulated hierarchical (micro–meso–macroporous) NaY_h zeolite: NaY_h, H-NaY_h, H-Y_h, Li-NaY_h, K-NaY_h, Ca-NaY_h, Mg-NaY_h, and La-NaY_h. Their physicochemical properties were characterized, and their catalytic activity and product selectivity were investigated in the aromatization of isophorone. The highest performance in the synthesis of 3,5-dimethylphenol was achieved in the presence of K-NaY_h, the catalyst distinguished both by the highest basicity among the tested samples and by low concentrations of weak Brønsted acid sites and Lewis acid sites. This sample exhibited a 3,5-dimethylphenol selectivity of 78.6% at an isophorone conversion of 98.9%. H-Y_h, H-NaY_h, Ca-NaY_h, Mg-NaY_h, and La-NaY_h provided the highest possible isophorone conversion (up to 100.0% at 400°C and 1 h^–1), with the reaction products mainly consisting of dimethylbenzenes and trimethylbenzenes (their selectivity reached up to 72.9 wt %). In the presence of low-activity samples (NaY_h and Li-NaY_h), the predominant products were methylbenzenes (dimethylbenzenes and trimethylbenzenes, 26.6–30.9%) and isophorone derivatives (β-isophorone and dihydroisophorone, 30.5–33.0%).

The paper investigates the effects of lanthanum and manganese promotion (3 wt %) on the physicochemical properties and catalytic performance of a supported 15%Co/Al₂O₃ catalyst in the synthesis of hydrocarbons from Co and H₂. The catalysts were prepared by impregnating the support with relevant metal nitrate solutions followed by drying, calcination, and hydrogen activation. The samples were characterized by X-ray diffraction analysis (XRD), low-temperature nitrogen adsorption, temperature-programmed reduction (TPR), and transmission electron microscopy (TEM). The catalytic performance was tested in fixed-bed flow-type reactors at 240°C, 2 MPa, and CO/H₂ = 1 : 2 with the feed GHSV being varied. At a CO conversion of about 50%, the promoted catalysts exhibited an increase in the C₅₊ selectivity and a drop in the methane selectivity in the order of Co < Co–La < Co–Mn. The Mn promotion increased the hydrocarbon chain growth probability up to 0.89, thus enhancing the yield of the most valuable products such as diesel-range and solid hydrocarbons. In the presence of 15Co3.15Mn/Al₂O₃, a C₅₊ selectivity of 45.3% was achieved at 86% CO conversion. Under high CO conversion conditions (80–86%), the selectivity towards higher hydrocarbons markedly declined, apparently due to the intensification of the water gas shift reaction. Nonetheless, even under these conditions, the Co–Mn catalyst provided the highest relative content of diesel-range hydrocarbons in the products. For 15Co3.15Mn/Al₂O₃, the C₁₁–C₁₈ selectivity reached 56.7 at 51.4% CO conversion and 41.2 at 86% CO conversion. The C₁₁–C₁₈ selectivity values provided by 15Co/Al₂O₃ were 10–20% lower (51.8 and 35.0%, respectively).

Recently the petroleum industry has been turning to the use of environmentally friendly additives particularly in oil well drilling operations. Switching to bio-based green biodegradable additives reduces pollution caused by dumping of wetted cuttings containing residual drilling fluid. The daily production of animal-origin biomass waste in farms poses serious health risks to both humans and animals if they are accumulated untreated. In this study, we used cow manure as a source of organic fly ash via burning it at temperatures below 370‒400°C to provide a manure conversion into powder and added it to a water-based drilling fluid. The results of the study showed that the biomass of the animal origin could successfully serve as a drilling fluid additive. For example, the rheological properties of the drilling fluid were improved via the provision of a sufficient YP/PV ratio and enhanced gelation properties. In addition, increasing fly ash concentration provided a subtle impact on mud density. XRD and EDS tests classified organic fly ash as a low-calcium/Class F, and the mud pH increased as the fly ash concentration increased. A FE-SEM imaging demonstrated that the fly ash morphology was amorphous with nano-sized particles dispersed among micro-sized particles. However, it is recommended to maintain the additive concentration below 0.55 wt %. Therefore, the use of the organic fly ash powder as an environmentally friendly additive is a good practice in oil well drilling operations.

The study proposes a novel method for synthesizing hierarchical Sn-BEA zeolites. This method consists of two successive steps: dealumination of a hierarchical Al-BEA zeolite prepared in a pre-concentrated reaction mixture; and incorporation of Sn by impregnating the dealuminated zeolite with a tin(IV) chloride ethanol solution. In the hierarchical zeolites, the Si/Sn ratio was varied between 29 and 41 by adding different amounts of the tin salt to the impregnating solution. The samples were tested in the Baeyer–Villiger catalytic oxidation of dihydrocarvone with hydrogen peroxide. The initial dihydrocarvone consumption rate has been found to increase with the concentration of Lewis acid sites in the samples and exceed that of the microporous Sn-BEA zeolite synthesized by a similar procedure except for the absence of the pre-concentration of the mixture. The highest yield of lactone (47%) has been achieved in the presence of the hierarchical Sn-BEA sample with the highest concentration of strong Lewis acid sites.

A series of additives based on Fe(III)-modified MFI, FAU, and FER zeolites were investigated with focus on their efficiency in reducing NO_x in cracking catalyst regeneration flue gases. The zeolite efficiency was found to depend on the zeolite framework type and the modification method. The Fe/MFI additives exhibited excellent performance. The additives prepared by ion exchange—and distinguished by uniform distribution of highly active metal ions (Fe³⁺)—reached a NO_x reduction efficiency of 45.4%.

Oil shale, an abundant unconventional resource, can be transformed into fossil fuels via pyrolysis, presenting a potential solution of energy shortages. This study explores the catalytic hydrothermal pyrolysis of oil shale using a novel organic porous amine catalyst, HCP-BBA, under subcritical water conditions. The study is focused on improving the efficiency and quality of shale oil extraction by overcoming the limitations of existing methods, such as high pyrolysis temperatures and extended heating time. The HCP-BBA catalyst, synthesized via a Friedel‒Crafts reaction, demonstrates excellent catalytic performance. Experimental results demonstrate that the introduction of HCP-BBA increases shale oil yield from 22.63 to 26.79%, shifts the product composition towards lower carbon numbers and lower boiling points, and increases the saturated hydrocarbon content by 13.1%, thereby enhancing the energy value of the shale oil. This study provides a promising approach for efficient and sustainable in situ oil shale conversion, proposing both theoretical and technical support for advanced extraction technologies.

Cyclopentane is an important organic raw material for the production of refrigerants and foaming agents. The relative volatilities of 2,2-dimethylbutane (DMB) and cyclopentane were determined in the presence of four extractants including dimethyl formamide (DMF, 100 wt %), N-methyl pyrrolidone (NMP, 100 wt %), DMF (80 wt %) + NMP (20 wt %), and DMF (79 wt %) + NMP (19 wt %) + sodium acetate (AcONa, 2 wt %). The results showed that the complex solvent containing AcONa provided a good separation effect, and the accuracy of the relative volatility determination was verified by the extractive distillation experiment. The process conditions for separating DMB and cyclopentane by extractive distillation with DMF (79 wt %) + NMP (19 wt %) + AcONa (2 wt %) as the extractant were systematically discussed. At the mass percentage of AcONa in DMF and NMP of ~2.0–2.5 wt %, mass ratio of solvent of about 6, the number of theoretical plates of about 30, the reflux ratio of about 3, and the solvent feed temperature of about 50°C, the composite extract (DMF (79 wt %) + NMP (19 wt %) + AcONa (2 wt %)) exhibited a better separation efficiency of the cyclopentane–DMB azeotropic system. According to the calculations of the process simulation, under the same operating conditions, the reboiler energy consumption could be reduced by 25.1% and the energy consumption for cooling could be reduced by 28.4% compared to that for the DMF solvent only.

Poly(castor oil(CO)–styrene(St)) (PCOS) was synthesized in toluene with azodiisobutyronitrile (AIBN) as the initiator using a Schlenk technology. The structure of PCOS was characterized by the Fourier transform infrared spectroscopy (FT-IR), Proton nuclear magnetic resonance (¹H NMR), and gel permeation chromatography (GPC), and the performance of the synthesized copolymer was evaluated as a solidification point depressant and a viscosity index improver. Experimental results show that when the optimum process conditions are m(CO) : m(St) = 1 : 1, and the AIBN mass fraction is 0.4% (based on the total mass of monomers) at 90°C for 6 h, the copolymer yield is 41%, the average relative molecular mass is 3.1  ×  10⁴, and the polydispersity index is 2.9. After addition of the synthesized copolymer, the solidification point of the lubricant fraction (350–395°C) can be decreased by 6–12°C, while the viscosity index can increase by 24–39. Therefore, the synthesized copolymer could be used as a lubricant additive with the double functions of reducing the solidification point and increasing the viscosity index.