Molecular simulation of the vapor-liquid equilibria of xylene mixtures: Force field performance, and Wolf vs. Ewald for electrostatic interactions

Caro-Ortiz, Sebastián; Hens, Remco; Zuidema, Erik; Rigutto, Marcello; Dubbeldam, David; Vlugt, Thijs J. H.

doi:10.1016/j.fluid.2018.12.006

Cited by 6 publications

(10 citation statements)

References 74 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[195]. The CFCMC method (both 2007 [59] and 2016 versions [123]) has been a frequently used method for studying VLE calculations [45,60,182,183,197], screening of gas solubilities of different compounds in various solvents [198][199][200], calculations of physisorption and chemisorption of different compounds in liquid solvents [42,64,[201][202][203][204][205][206][207][208][209][210]. Recently, Mullen and Maginn [63] introduced an adaptation of the reaction ensemble combined with the CFCMC method in which pairwise transformation of xylene isomers is simulated by performing walks in λ-space.…”

Section: Other Recent Applications Of the Cfcmc Methodsmentioning

confidence: 99%

Recent advances in the continuous fractional component Monte Carlo methodology

Rahbari

Hens

Ramdin

et al. 2020

Molecular Simulation

Self Cite

View full text Add to dashboard Cite

In this paper, we review recent advances in the Continuous Fractional Component Monte Carlo (CFCMC) methodology and present a historic overview of the most important developments that have led to this method. The CFCMC method has gained attention for Monte Carlo simulations of adsorption at high loading, and phase and reaction equilibria of dense systems. It has recently been extended to reactive systems. The main features of the CFCMC method are: (1) Increased molecule exchange efficiency between different phases in single and multicomponent (reactive) systems, which improves the efficiency and accuracy of phase equilibria simulations at high densities; (2) Direct calculation of the chemical potential from a single simulation; (3) Direct calculation of partial molar properties from a single simulation. The developed simulation techniques are incorporated in the open-source molecular simulation software Brick-CFCMC.

show abstract

Section: Other Recent Applications Of the Cfcmc Methodsmentioning

confidence: 99%

Recent advances in the continuous fractional component Monte Carlo methodology

Rahbari

Hens

Ramdin

et al. 2020

Molecular Simulation

Self Cite

View full text Add to dashboard Cite

show abstract

“…For these reasons, the zeolite frameworks are considered rigid. Force fields for the interactions between aromatic molecules are typically fitted to model the vapor–liquid equilibrium with LJ potentials or a combination of LJ and electrostatic interactions. , Guest–guest force fields that use electrostatic interactions (such as OPLS , ) have been used to a great extent for the simulation of adsorption of aromatics in zeolites. − , The electrostatic interactions of guest–guest force fields of aromatics are fitted for VLE and not for interaction with a host framework . Also, the electrostatic interactions included in the TraPPE-zeo model are fitted and tested for the adsorption of CO 2 , and not for aromatic/zeolite systems.…”

Section: Methodsmentioning

confidence: 99%

“…Force fields for the interactions between aromatic molecules are typically fitted to model the vapor−liquid equilibrium with LJ potentials or a combination of LJ and electrostatic interactions. 125,126 Guest−guest force fields that use electrostatic interactions (such as OPLS 127,128 ) have been used to a great extent for the simulation of adsorption of aromatics in zeolites. [76][77][78]129 The electrostatic interactions of guest−guest force fields of aromatics are fitted for VLE and not for interaction with a host framework.…”

Section: Methodsmentioning

confidence: 99%

“…Details about these calculations can be found in the Supporting Information. Given the similarity of the thermodynamic properties of xylene isomers, 125,126 it is expected that the vapor pressure of the mixture of xylenes is close to the vapor pressure of the xylene isomers. From experiments, it is known that the vapor pressure of m-xylene (at 523 K) is 9.85 bar, 145 for o-xylene (at 523 K) it is 8.83 bar, 146 and for p-xylene (at 520 K) it is 9.419 bar.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Competitive Adsorption of Xylenes at Chemical Equilibrium in Zeolites

et al. 2021

Self Cite

View full text Add to dashboard Cite

The separation of xylenes is one of the most important processes in the petrochemical industry. In this article, the competitive adsorption from a fluid-phase mixture of xylenes in zeolites is studied. Adsorption from both vapor and liquid phases is considered. Computations of adsorption of pure xylenes and a mixture of xylenes at chemical equilibrium in several zeolite types at 250 °C are performed by Monte Carlo simulations. It is observed that shape and size selectivity entropic effects are predominant for small one-dimensional systems. Entropic effects due to the efficient arrangement of xylenes become relevant for large one-dimensional systems. For zeolites with two intersecting channels, the selectivity is determined by a competition between enthalpic and entropic effects. Such effects are related to the orientation of the methyl groups of the xylenes. m -Xylene is preferentially adsorbed if xylenes fit tightly in the intersection of the channels. If the intersection is much larger than the adsorbed molecules, p -xylene is preferentially adsorbed. This study provides insight into how the zeolite topology can influence the competitive adsorption and selectivity of xylenes at reaction conditions. Different selectivities are observed when a vapor phase is adsorbed compared to the adsorption from a liquid phase. These insight have a direct impact on the design criteria for future applications of zeolites in the industry. MRE-type and AFI-type zeolites exclusively adsorb p -xylene and o -xylene from the mixture of xylenes in the liquid phase, respectively. These zeolite types show potential to be used as high-performing molecular sieves for xylene separation and catalysis.

show abstract

“…Molecular simulations of aromatics typically use force fields (guest–guest interactions) that model the vapor–liquid equilibrium (VLE) with LJ potentials or a combination of LJ and electrostatic interactions. , In the case of aromatic species, a common practice in the development of these force fields is to fit the interaction parameters to reproduce the VLE of the pure components − or by ab initio quantum mechanical calculations. − …”

Section: Methodsmentioning

confidence: 99%

Adsorption of Aromatics in MFI-Type Zeolites: Experiments and Framework Flexibility in Monte Carlo Simulations

et al. 2020

Self Cite

View full text Add to dashboard Cite

Computer simulations of adsorption of aromatics in zeolites are typically performed using rigid zeolite frameworks. However, adsorption isotherms for aromatics are very sensitive to small differences in the atomic positions of the zeolite (Chem. Phys. Lett., 1999, 308, 155−159). This article studies the effect of framework flexibility on the adsorption of aromatics in MFI-type zeolites computed by grand-canonical Monte Carlo simulations. New experimental data of adsorption of ethylbenzene in a MFItype zeolite at 353 K is presented. The adsorption of n-heptane, ethylbenzene, and xylene isomers is computed in three MFI-type zeolite structures. It is observed that the intraframework interactions in flexible framework models induce small but important changes in the atom positions of the zeolite and hence in the adsorption isotherms. Framework flexibility is differently "rigid": flexible force fields produce a zeolite structure that vibrates around a new equilibrium configuration with limited capacity to accommodate to a bulky guest molecule. The vibration of the zeolite atoms only plays a role at high loadings, and the adsorption is mainly dependent on the average positions of the atoms. The simulations show that models for framework flexibility should not be blindly applied to zeolites and a general reconsideration of the parametrization schemes for such models is needed.

show abstract

Molecular simulation of the vapor-liquid equilibria of xylene mixtures: Force field performance, and Wolf vs. Ewald for electrostatic interactions

Cited by 6 publications

References 74 publications

Recent advances in the continuous fractional component Monte Carlo methodology

Recent advances in the continuous fractional component Monte Carlo methodology

Competitive Adsorption of Xylenes at Chemical Equilibrium in Zeolites

Adsorption of Aromatics in MFI-Type Zeolites: Experiments and Framework Flexibility in Monte Carlo Simulations

Contact Info

Product

Resources

About