Petroleum Chemistry最新文献

The initial information for calculating the physical, chemical, and operational properties of gasoline is data on its group composition. The complex composition of gasoline fractions (according to capillary gas chromatography (CGC), comprising about 150–250 components) greatly complicates the rapid determination and identification of unsaturated hydrocarbons, which are the most important part of gasoline. As a rule, it is not possible to achieve complete separation of chromatographic peaks even on highly efficient 100-meter capillary columns. Poor reproducibility of the properties of capillary columns requires a large number of comparison samples, which complicates the identification of the separated components. A combination of high-performance liquid chromatography (HPLC) and CGC methods allows simplifying the methodology and increasing the accuracy and rapidity of the analysis.

The physicochemical properties of a series of pelletized SAPO-11 molecular sieves differing in the binder (Al₂O₃) content were characterized; their activity and selectivity were investigated in the hydroisomerization of n-hexadecane. An increase in the binder content from 20 to 60 wt % was found to decrease the specific micropore volume and increase the external specific surface area as well as the mechanical strength, activity, and selectivity of Pt-containing samples in the hydroisomerization of n-hexadecane. The study proposes the formulations of pelletized SAPO-11 that ensure mechanical (axial crushing) strength of 9.9 to 15.1 N/mm² and the yield of C₁₆ isomers up to 78% in the hydroisomerization of n-hexadecane.

The paper proposes a series of promising Zr(IV) complexes and experimentally confirms that, when activated with minimal amounts of modified metylaluminoxane MMAO-12 ([Al]/[Zr] ~20–40), these complexes are able to initiate copolymerization of hex-1-ene with polar vinyl monomers FG-(CH₂)₈CH=CH₂ [where FG is a functional group selected from C(O)NMe₂, CH₂OSiMe₃, C(O)OⁱPr, and CH₂OH]. The prepared copolymers were characterized by ¹H and ¹³C NMR spectroscopy, size exclusion chromatography, and differential scanning calorimetry. Isotactic copolymers of hex-1-ene with 10-undecen-1-ol with polar comonomer content up to 32.2 mol % have been synthesized for the first time. An investigation of the adhesive properties of the prepared copolymers has shown that incorporating 10-undecen-1-ol enhances the adhesive fracture energy by a factor of 32 compared to the respective homopolymer.

A series of Ni₂P catalysts on an Al₂O₃-SAPO-11 composite support were synthesized by two different methods: reduction of Ni and P precursors by hydrogen at elevated temperatures (TPR); and phosphidation of supported Ni metallic particles by triphenylphosphine (PPh3). For loading active components, aqueous solutions prepared from different precursors (specifically, Ni(OAc)₂ and (NH₄)₂HPO₄; Ni(OH)₂ and H₃PO₃; and Ni(OAc)₂ and H₃PO₂) were used in the first case, and a Ni(OAc)₂ solution was used in the second. The catalysts were characterized by chemical analysis, H₂-TPR, NH₃-TPD, XRD, TEM, XPS, and ²⁷Al M­­AS NMR. The catalyst performance was tested in hydroprocessing of a model compound of fatty acid triglycerides, specifically methyl palmitate (MP). The formation of a Ni₂P phase was confirmed by XRD, TEM, and XPS; moreover, the synthesis method was found to affect the localization of Ni₂P nanoparticles. It was further revealed that, in the TPR method, the particles are predominantly located on the Al₂O₃ surface, whereas the PPh3 method produces particles on the surfaces of both Al₂O₃ and SAPO-11. The main MP conversion products are n- and iso-alkanes (C₁₅ and C₁₆). At 100% conversion of oxygenates, the PPh3-synthesized catalyst achieved a higher iso-alkane selectivity (63%) than the TPR-prepared samples (2–21%).

The study investigates catalytic conversion of polyethylene and polypropylene—in the form of 1–5 wt % solutions in vacuum distillate—to light olefins in the presence of a catalyst based on a mixture of zeolites Y and ZSM-5. The effects of reaction conditions and polymer pretreatment methods on the conversion degree and product selectivity are discussed. At 675°C quantitative conversion of the polyolefins was achieved, and the products mainly consisted of C₂–C₄ light olefins. The cracking of the polymer solutions enhanced the yield of light olefins compared to the pure vacuum distillate case, the enhancement reaching up to 9.9 wt %, including 5.2 wt % for propylene.

A series of BEA-type zeolites with SiO₂/Al₂O₃ ratios of about 50 were synthesized by steam-assisted (SAC) and hydrothermal crystallization (HTC) in fluoride and alkaline media. Their physicochemical properties were characterized by low-temperature nitrogen adsorption, XRD, SEM, XRF, and NH₃-TPD. The catalytic performance was investigated in liquid-phase toluene disproportionation. The SAC-synthesized samples were distinguished by a higher concentration of acid sites. The BEAs prepared by SAC in alkaline media exhibited a higher activity in toluene disproportionation. The samples synthesized in fluoride media, both by steam-assisted and hydrothermal crystallization, proved to be comparable in activity.

A series of ZSM-5 samples were synthesized by template-free hydrothermal synthesis without adding seed crystals. When synthesis parameters such as temperature, duration, and molar ratio of components being equal, various silicas (specifically, Silica-Fumed from Sigma-Aldrich; Rosil-175 from the Bashkir Soda Company (BSC), Russia; Silica from the Salavat Catalyst Plant (SCP), Russia; and Aerosil-300 from Evonik, Germany) and of aluminum (Al(NO₃)₃∙9H₂O and NaAlO₂) were varied. In the presence of sodium aluminate, highly crystalline ZSM-5 samples were synthesized, whereas the use of aluminum nitrate led to an amorphous product due to accelerating aluminosilicate condensation. The ZSM-5 crystals prepared from various SiO₂ sources have different morphology, including the crystal size (ranging from 5.9 to 12.2 µm) and the aspect ratio (from 1.9 to 2.6). The ZSM-5 samples synthesized from available Russian-manufactured SiO₂ sources (Rosil-175 (BSC) and Silica (SCP)) in the presence of sodium aluminate consisted of crystals with average sizes of 5.9 and 6.9 μm, respectively, and a narrow particle size distribution (c_v < 20%).

A series of tandem catalysts based on a ZnGa₂O₄ spinel and on MFI-type acidic components with varying SiO₂/Al₂O₃ ratios were prepared by mechanical mixing at a spinel to MFI weight ratio of 2 : 1. These catalysts were tested in the conversion of carbon dioxide to olefins at 380°C and 27 bar. The hydrogenating component (ZnGa₂O₄) was prepared by co-precipitation of the corresponding hydroxides followed by heat treatment. The zeolites were synthesized by steam-assisted crystallization. A reference catalyst was prepared from ZnGa₂O₄ and a hydrothermally synthesized commercial zeolite CBV28014. The physicochemical properties of the catalysts and their components were characterized by low-temperature nitrogen adsorption–desorption, chemical analysis, NH₃-TPD, H₂-TPR, XRD, and SEM. The sample with the highest SiO₂/Al₂O₃ ratio (250) achieved the highest CO₂ conversion; this parameter dropped as the aluminum content in the samples increased. The highest selectivity towards light olefins was observed for the catalyst with SiO₂/Al₂O₃ = 172 in the acidic component, likely because this zeolite had an optimum acidity for the production of light olefins.

Petrophysical parameters were assessed using comprehensive log data coming from two wells (Ns-2, Ns-4) located within the Mishrif, Rumaila, Ahmadi, and Mauddud formations within the Nasiriya oil field, Iraq. The logs were digitized using Techlog 2015 software, and environmental modifications were implemented to guarantee precise interpretations. The shale volume used to be determined using gamma ray (GR) logs, subsequently leading towards the calculation of the effectiveness porosity. Water saturation is used to be calculated alongside Archie's equation. The investigation indicated that the lithology regarding the Mishrif, Rumaila, Ahmadi, and Mauddud formations happens to be predominantly limestone, alongside calcite like the principal mineral within the matrix. All formations were found to contain water like the fluid type, except within favor regarding the Mishrif formation at the 2013–2046 m within Ns-2, and 2000–2060 m within Ns-4, where hydrocarbons were identified. The top strata for these depths comprise substantial shale alongside limited effective porosity, serving like cap rock at the depths from 2013 to 2016 m within Ns-2, and 2000 towards 2006 m within Ns-4.