Separation of 1-Butene and 2-Butene Isomers via Nanoporous Graphene: A Molecular Simulation Study

Xu, Yong; Zhu, Huajian; Wang, Min; Xu, Jun; Yang, Chao

doi:10.1021/acs.iecr.0c00362

Cited by 2 publications

(5 citation statements)

References 44 publications

(68 reference statements)

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“…The force field has been used to demonstrate the resin and asphaltene density and behavior of aggregation. , The non-bonded interactions between the atoms were described by the Lennard-Jones potential, and the interaction parameters are presented in Table . The cross-potential parameters were obtained using the Lorentz–Berthelot mixing rules . The non-bond interaction had a cutoff radius of 10 Å.…”

Section: Methodsmentioning

confidence: 99%

“…The cross-potential parameters were obtained using the Lorentz− Berthelot mixing rules. 42 The non-bond interaction had a cutoff radius of 10 Å. The charges of the atoms were assigned according to the CVFF database.…”

Section: ■ Methodsmentioning

confidence: 99%

“…The interaction energies ΔE were calculated by ΔE = E t − E i − E m , in which, E t is the total energy of the system, E i is the energy of metal ion, E m is the energy of the molecule containing the corresponding functional group, and all the atoms were kept frozen to avoid the conformational changes. The DFT was performed with the generalized gradient approximation of the Perdew−Burke−Ernzerhof form in the Dmol3 module embedded in MS. 42 The double numerical plus polarization basis set was chosen. The tolerance of self-consistent field was 10 −6 a.u.…”

Section: ■ Methodsmentioning

confidence: 99%

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Molecular Dynamics Simulation Reveals Unique Rheological and Viscosity–Temperature Properties of Karamay Heavy Crude Oil

Zhu

Zhang

et al. 2021

Energy Fuels

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Heavy oil, with high viscosity and complex compositions, often faces a series of challenges in the process of its exploitation and utilization. There are huge amounts of compositions with different molecular structures in heavy oil, and it is a great challenge to clarify the influence of the microstructure of heavy oil on the rheological and viscosity–temperature properties. Based on the experimental data, such as acid value, element content, functional group type of the heavy oil, and so on, we constructed six types of heavy oils from three regions to reveal the unique properties of Karamay heavy oil. Molecular dynamics simulation was used to study the effects of the compositions and the aggregation structure on the rheological and viscosity–temperature properties of heavy oil. The results show that the rheological properties of Karamay heavy oil with low asphaltene concentration are dominated by molecular conformation, and heavy oil with molecules that are not easily stretched has a higher viscosity. When the concentration of asphaltene is high, the nanoaggregates formed by asphaltene molecules and their variation with shear rate affect the viscosity. Compared with the aggregates by the island structure asphaltene molecules, the larger nanoaggregate size of continental structure due to stronger π–π interaction leads to the increase in viscosity. However, the viscosity decreases faster with the increase in shear rate, which is attributed to the more orderly aggregate structure of polycondensed aromatic rings that can be easily pulled along the velocity plane. In addition, we found that metal ions, as a bridge, can interact with molecules containing different heteroatoms, forming larger clusters and increasing the viscosity of Karamay heavy oil. For the viscosity–temperature properties, the more intense thermal movement of molecules with the increased temperature weakens the interaction between the aromatic rings and decreases the viscosity of heavy oils.

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Section: Methodsmentioning

confidence: 99%

Section: ■ Methodsmentioning

confidence: 99%

Section: ■ Methodsmentioning

confidence: 99%

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Molecular Dynamics Simulation Reveals Unique Rheological and Viscosity–Temperature Properties of Karamay Heavy Crude Oil

Zhu

Zhang

et al. 2021

Energy Fuels

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“…In this regard, atomic‐scale simulations have been carried out to estimate the gas permeances more precisely. Figure summarizes the simulation results of gas permeation through NATM pores using molecular dynamics (MD) simulations, [ 59,61,63,64,66,67,73–75,86–107 ] ab initio calculations, [ 29,70,83,108–121 ] or a combination of both, [ 72,82,122–137 ] as well as experimental results of gas permeation through individual graphene nanopores. [ 60,138 ] The gases considered in Figure 4 include H 2 , He, H 2 O, CO 2 , N 2 , O 2 , CH 4 , H 2 S, Ar, SF 6 , ethane, and ethene.…”

Section: Theoretical and Simulation Advancesmentioning

confidence: 99%

“…a) Compilation of simulation, analytical modeling, and experimental data of gas permeance per pore (normalized by the square root of the gas molecular weight) as a function of the pore diameter D p (normalized by the gas kinetic diameter D m ). The simulation methods used include MD, [ 59,61,63,64,66,67,73–75,86–107 ] ab initio calculations, [ 29,70,83,108–121 ] and a combination of both. [ 72,82,122–137 ] The experimental results are taken from ref.…”

Section: Theoretical and Simulation Advancesmentioning

confidence: 99%

Gas Separations using Nanoporous Atomically Thin Membranes: Recent Theoretical, Simulation, and Experimental Advances

Yuan

et al. 2022

Advanced Materials

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The separation of gaseous mixtures is essential in the chemical industry, including hydrogen separation in ammonia or petrochemical plants, nitrogen separation from air, CO 2 separation in natural gas processing, [7] olefin/ paraffin separation, [1] and H 2 S separation from sour gas. [8] Similar to separation processes in general, thermal-based gasseparation methods, such as cryogenic distillation, amine adsorption, and vapor condensation, consume a high amount of energy, which can be significantly reduced using gas-separation membrane units. [5,8] A membrane that can separate gases allows certain components in a mixture to permeate at higher rates than others. The economic competitiveness of a gas-separation membrane highly depends on its gas permeance K and its selectivity S. The permeance K i of gas species i (in SI units of mol m −2 s −1 Pa −1 ) is defined as K i = F i /Δp i , where F i (in SI units of mol m −2 s −1 ) is the flux of gas i through the membrane, and Δp i is the partial pressure difference (the driving force) of gas i between the feed side and the permeate side. For relatively thick conventional membranes, whose crossmembrane transport resistance is dominated by the bulk interior, the permeance K i is inversely proportional to the membrane thickness d. Correspondingly, the permeability P i of gas i (in SI units of mol m −1 s −1 Pa −1 ) is defined aswhich is an intrinsic property of a material. The selectivity S ij between gases i and j is defined as S ij = K i /K j = P i /P j .Polymers have been the most widely used materials for gasseparation membranes for decades because of their relatively low cost and low manufacturing difficulty. [8,9] However, membrane separations using state-of-the-art polymeric membranes cannot outcompete the thermal-based separation methods economically. [7] One of the limitations of the polymeric membranes is the trade-off between permeability and selectivity, originally investigated by Robeson. [10,11] The best combination of permeability and selectivity for a binary gas pair is referred to as the polymer upper bound. This trade-off originates from the interplay between the free volume spacing in the polymer matrices and the size of the gas molecules. [12] Smaller polymeric spacing increases the selectivity but sacrifices the permeability due to the lower gas Porous graphene and other atomically thin 2D materials are regarded as highly promising membrane materials for high-performance gas separations due to their atomic thickness, large-scale synthesizability, excellent mechanical strength, and chemical stability. When these atomically thin materials contain a high areal density of gas-sieving nanoscale pores, they can exhibit both high gas permeances and high selectivities, which is beneficial for reducing the cost of gas-separation processes. Here, recent modeling and experimental advances in nanoporous atomically thin membranes for gas separations is discussed. The major challenges involved, including controlling pore size distributions, scaling up the membrane ar...

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Separation of 1-Butene and 2-Butene Isomers via Nanoporous Graphene: A Molecular Simulation Study

Cited by 2 publications

References 44 publications

Molecular Dynamics Simulation Reveals Unique Rheological and Viscosity–Temperature Properties of Karamay Heavy Crude Oil

Molecular Dynamics Simulation Reveals Unique Rheological and Viscosity–Temperature Properties of Karamay Heavy Crude Oil

Gas Separations using Nanoporous Atomically Thin Membranes: Recent Theoretical, Simulation, and Experimental Advances

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