Elucidating the mechanisms of titanium–induced morphological and structural changes in catalysts on mesoporous Al2O3–TiOx mixed oxides: Effect of non–stoichiometric TiOx phase

Obeso–Estrella, R.; Pawelec, B.; Mota, N.; Flores, Laura Lorena Díaz; Melgoza, Juan Manuel Quintana; Yocupicio-Gaxiola, Rosario I.; Zepeda, T.A.

doi:10.1016/j.micromeso.2022.111991

Cited by 7 publications

(3 citation statements)

References 84 publications

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“…The Dmol module was utilized for geometric optimization calculations. The GGA-PBE functional was used with the DND 4.4 basis set, and the maximum convergence step was set to 5000.…”

Section: Methodsmentioning

confidence: 99%

“…For the heptane + thiophene + EG system, a cell of 22 × 22 × 22 Å 3 was created, which included 100 molecules of EG and 10 molecules each of heptane and thiophene, with the overall density being set to 1.113 g/cm 3 . For the heptane + thiophene + NMP system, a cell of 26 × 26 × 26 Å 3 was created, which included 100 molecules of NMP and 10 molecules each of heptane and thiophene, and the overall density was set to 1.028 g/cm 3 . The Forcite module was selected, and COMPASS II was used as the force field.…”

Section: Distribution Constant and Separationmentioning

confidence: 99%

“…The rapid development of the automobile industry and increasingly stringent environmental protection regulations have led to much higher requirements for fuel oil quality. − During engine combustion, sulfur compounds in fuels are converted to sulfur oxides (SO x ), which, upon emission into the atmosphere, can pollute the environment by forming acid rain and can damage human health. Therefore, reducing the sulfur content of fuel oils is critical, with research focusing on the development of desulfurization technologies.…”

Section: Introductionmentioning

confidence: 99%

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Liquid–Liquid Equilibrium Data and Mechanism for Separating Thiophene from Heptane Using Mixed Solvents

Yang,

Xu,

Xie

et al. 2024

J. Chem. Eng. Data

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Solvent extraction is a promising method for removing organic sulfides from fuel oils in refineries. However, selecting an appropriate extractant requires a fundamental understanding of liquid–liquid equilibria. In this study, we collected liquid–liquid equilibrium (LLE) data for ternary heptane + thiophene + solvent systems at 298.2 K and 101.3 kPa. The extraction capabilities of the selected solvents (ethylene glycol (EG), N-formylmorpholine, 1,3-propanediol, 1,4-butanediol, 1,2-propanediol, N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide, and benzyl alcohol) for separating heptane and thiophene were assessed based on the distribution constant (D) and separation factor (S). NMP exhibited the highest D value, whereas EG exhibited the lowest. In contrast, the EG had the highest S value. Therefore, to balance D and S simultaneously, mixtures of EG and NMP at different molar ratios were used as extractants. Molecular-level investigation into the separation mechanism was conducted via molecular dynamics simulations and density functional theory calculations. The enhanced S value of EG was attributed to a significant difference in its interaction energies with thiophene and heptane, whereas the enhanced D value of NMP resulted from a more negative solvation-free energy upon binding thiophene. Finally, a comparison of the thermodynamic models showed that the nonrandom two-liquid (NRTL) model and the universal quasichemical (UNIQUAC) model were equally suitable for correlating the experimental data for the ternary and quaternary heptane + thiophene + solvent systems; the root-mean-square deviation (RMSD) values for the NRTL model were all <1%, whereas the maximum RMSD value for the UNIQUAC model was 1.57%. The obtained liquid–liquid equilibrium data and mechanistic insights can aid in improving extractive desulfurization using conventional organic solvents toward the efficient, low-cost, and simple production of clean fuel oils with ultralow sulfur contents.

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“…The Dmol module was utilized for geometric optimization calculations. The GGA-PBE functional was used with the DND 4.4 basis set, and the maximum convergence step was set to 5000.…”

Section: Methodsmentioning

confidence: 99%

Section: Distribution Constant and Separationmentioning

confidence: 99%