Second-generation kernel for characterization of carbonaceous material by adsorption

Lucena, Sebastião M. P.; Oliveira, José Carlos; Gonçalves, Daniel V.; Silvino, Pedro F.G.

doi:10.1016/j.carbon.2017.04.061

Cited by 15 publications

(7 citation statements)

References 44 publications

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“…The system can be properly described by using Lennard-Jones potentials plus Coulomb contributions. Biased Monte Carlo simulation in the grand canonical ensemble was performed using the slit-pore model and associated parameters to represent the activated carbon. A validated H 2 S molecule model with parameters optimized to reproduce literature adsorption heat was used for the gas.…”

Section: Resultsmentioning

confidence: 99%

Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons

Menezes

Moura

Lucena

et al. 2018

Ind. Eng. Chem. Res.

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Adsorption of H2S onto porous materials is as an attractive technology for fine biogas cleaning. Three activated carbon samples were studied as adsorbents for biogas desulfurization at low concentration (100 ppm), in order to better understand the underlying mechanisms and provide a basis for the development of new materials. One of the carbons is impregnated with NaOH, another with Fe2O3 and the third one is the parent material. Molecular simulation was performed to distinguish the retention mechanism. Textural characterization revealed high surface areas and the existence of ultramicropores with sizes below 4 Å in all samples. The possibility of discriminating the retention regimes emphasized the great influence of the chemisorption in these systems increasing up to 50 times the capacity of retention of H2S for the sodium-impregnated sample (from 0.3 to 15.64 mg g–1). Surprisingly, both physisorption and chemisorption could be unequivocally detected for the nonimpregnated sample by evaluating breakthrough curves in different temperatures (up to 423 K). The evaluation of regeneration by heat indicated that the adsorbents can recover about 50% and 20% of their initial capacity for nonimpregnated and impregnated samples, respectively.

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Section: Resultsmentioning

confidence: 99%

Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons

Menezes

Moura

Lucena

et al. 2018

Ind. Eng. Chem. Res.

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“…Among the models proposed in the literature for activated carbon (Do and Do 2006;Lucena et al 2008Lucena et al , 2017Nguyen et al 2008;Oliveira et al 2011), we choose the most used model. The molecular representation of activated carbon is then de ned as slits of graphene layers walls.…”

Section: Methodsmentioning

confidence: 99%

Prediction of chlorophenols adsorption on activated carbons by representative pores method

Oliveira

Rodrigues

Lucena

2022

Environ Sci Pollut Res

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The speci cation of a particular activated carbon adsorbents for removal of phenol and related derivatives, from dilute aqueous solutions, is still based on lengthy trial and error experimental tests. A predictive model of adsorption of these compounds would considerably reduce the carbon selection time and could also bring new information to support more e cient carbon synthesis. The use of molecular simulation and the methodology of representative pores, proved to be adequate for quantitative prediction of phenol adsorption. Here the methodology is being extended to chlorophenols, an important class of phenol-derived pollutants. A set of ortho and para-chlorophenol isotherms were simulated for different representative pores in order to predict carbon adsorption and determine the most signi cative pore size. At low concentrations (1x10 -4 mol/L), the pores of 8.9 and 18.5 Å are the most effective. For concentrations above 3 x10 -4 mol/L pores in the range of 27.9 Å must be present in the activated carbon.The adsorption isotherm difference between ortho and para-chlorophenol, identi ed experimentally, was reproduced in the simulation and its origin was investigated further. Finally, the adsorption isotherms of chlorophenols for other activated carbons were predicted with the help of the model.

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“…Nanoscale models have been reviewed by Jagiello and Olivier 5 recently. Included are models that account for geometric surface vacancies, 14,15 variable wall thickness, 16 or variable surface density 6,17 and also models that add a periodic function to the solid−fluid interaction potential in a direction parallel to the pore wall. 5,18,19 While the quenched solid density functional theory 6 and also the 2D-NLDFT 5 give good agreement with experimental low pressure adsorption data, they are limited in that they allow for only one kind of heterogeneity at a time (i.e., either structural or chemical heterogeneity).…”

Section: Introductionmentioning

confidence: 99%

“…Nanoscale models have been reviewed by Jagiello and Olivier recently. Included are models that account for geometric surface vacancies, , variable wall thickness, or variable surface density , and also models that add a periodic function to the solid–fluid interaction potential in a direction parallel to the pore wall. ,, While the quenched solid density functional theory and also the 2D-NLDFT give good agreement with experimental low pressure adsorption data, they are limited in that they allow for only one kind of heterogeneity at a time (i.e., either structural or chemical heterogeneity). Jagiello and Olivier have attempted to include both geometric and chemical effects into one comprehensive model; however, their model does not permit variation of the energetic site densities and fails to consider the electrostatic interactions, which are of particular importance for the adsorption of polar molecules, for example, water and carbon dioxide, onto grafted or oxidized surfaces at a low pressure.…”

Section: Introductionmentioning

confidence: 99%

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Conformal Sites Theory for Adsorbed Films on Energetically Heterogeneous Surfaces

2020

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We present a conformal sites theory for a solid substrate whose surface is both geometrically and energetically heterogeneous and that interacts with an adsorbed film. The theory is based on a perturbation expansion for the grand potential of a real system with a rough surface about that of a reference system with an ideal reference surface, thus mapping the real system onto a much simpler interfacial system. The expansion is in powers of the intermolecular potential parameters, and leads to mixing rules for the potential parameters of the reference system. Grand canonical Monte Carlo simulations for the adsorption of argon at 87.3 K, carbon dioxide at 273 K, and water vapor at 298 K on heterogeneous carbon surfaces are investigated to explore the limits of applicability of the theory. Simulation results indicate that the theory works well with typical asymmetry of the potential parameters in the force field. However, care should be taken when applying the theory to strongly associating fluids and in the low-pressure region where the active surface sites play an important role. The conformal sites theory can be used to predict the adsorption properties and to characterize the solid substrate by taking advantage of the corresponding states principle. Other possible applications are also discussed.

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Second-generation kernel for characterization of carbonaceous material by adsorption

Cited by 15 publications

References 44 publications

Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons

Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons

Prediction of chlorophenols adsorption on activated carbons by representative pores method

Conformal Sites Theory for Adsorbed Films on Energetically Heterogeneous Surfaces

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Second-generation kernel for characterization of carbonaceous material by adsorption

Cited by 15 publications

References 44 publications

Insights on the Mechanisms of H2S Retention at Low Concentration on Impregnated Carbons

Insights on the Mechanisms of H2S Retention at Low Concentration on Impregnated Carbons

Prediction of chlorophenols adsorption on activated carbons by representative pores method

Conformal Sites Theory for Adsorbed Films on Energetically Heterogeneous Surfaces

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Product

Resources

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Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons

Insights on the Mechanisms of H₂S Retention at Low Concentration on Impregnated Carbons