Monte Carlo simulations on adsorptions of benzene and xylenes in sodium-Y zeolites

Kitagawa, Tetsuji; Tsunekawa, Tetsuya; Iwayama, Kazuyoshi

doi:10.1016/s0927-6513(96)00025-9

Cited by 27 publications

(27 citation statements)

References 20 publications

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“…However, the application of Equation (13) is complex from the implementation point of view. A common choice of the proposal is the transition prior function [18,85]:

q (x_{k}^{i} | x_{0 : k - 1}^{i}, y_{1 : k}) = p (x_{k}^{i} | x_{0 : k - 1}^{i})

…”

Section: Data Assimilation Theorymentioning

confidence: 99%

“…Often the Sampling Importance Resampling PF is used (SIR-PF) [18]. Alternative methods are Residual Sampling [88] and Stochastic Universal Resampling [85]. The latter have the advantage that they reduce sampling noise, and it has been shown that stochastic universal sampling has the lowest sampling noise [85].…”

Section: Data Assimilation Theorymentioning

confidence: 99%

“…Alternative methods are Residual Sampling [88] and Stochastic Universal Resampling [85]. The latter have the advantage that they reduce sampling noise, and it has been shown that stochastic universal sampling has the lowest sampling noise [85]. Resampling slows down the degeneration of the weights, but it does not solve the problem.…”

Section: Data Assimilation Theorymentioning

confidence: 99%

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Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Montzka

Pauwels

Franssen

et al. 2012

Sensors

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More and more terrestrial observational networks are being established to monitor climatic, hydrological and land-use changes in different regions of the World. In these networks, time series of states and fluxes are recorded in an automated manner, often with a high temporal resolution. These data are important for the understanding of water, energy, and/or matter fluxes, as well as their biological and physical drivers and interactions with and within the terrestrial system. Similarly, the number and accuracy of variables, which can be observed by spaceborne sensors, are increasing. Data assimilation (DA) methods utilize these observations in terrestrial models in order to increase process knowledge as well as to improve forecasts for the system being studied. The widely implemented automation in observing environmental states and fluxes makes an operational computation more and more feasible, and it opens the perspective of short-time forecasts of the state of terrestrial systems. In this paper, we review the state of the art with respect to DA focusing on the joint assimilation of observational data precedents from different spatial scales and different data types. An introduction is given to different DA methods, such as the Ensemble Kalman Filter (EnKF), Particle Filter (PF) and variational methods (3/4D-VAR). In this review, we distinguish between four major DA approaches: (1) univariate single-scale DA (UVSS), which is the approach used in the majority of published DA applications, (2) univariate multiscale DA (UVMS) referring to a methodology which acknowledges that at least some of the assimilated data are measured at a different scale than the computational grid scale, (3) multivariate single-scale DA (MVSS) dealing with the assimilation of at least two different data types, and (4) combined multivariate multiscale DA (MVMS). Finally, we conclude with a discussion on the advantages and disadvantages of the assimilation of multiple data types in a simulation model. Existing approaches can be used to simultaneously update several model states and model parameters if applicable. In other words, the basic principles for multivariate data assimilation are already available. We argue that a better understanding of the measurement errors for different observation types, improved estimates of observation bias and improved multiscale assimilation methods for data which scale nonlinearly is important to properly weight them in multiscale multivariate data assimilation. In this context, improved cross-validation of different data types, and increased ground truth verification of remote sensing products are required.

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“…However, the application of Equation (13) is complex from the implementation point of view. A common choice of the proposal is the transition prior function [18,85]:

q (x_{k}^{i} | x_{0 : k - 1}^{i}, y_{1 : k}) = p (x_{k}^{i} | x_{0 : k - 1}^{i})

…”

Section: Data Assimilation Theorymentioning

confidence: 99%

Section: Data Assimilation Theorymentioning

confidence: 99%

Section: Data Assimilation Theorymentioning

confidence: 99%

See 1 more Smart Citation

Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Montzka

Pauwels

Franssen

et al. 2012

Sensors

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show abstract

“…With alkali metal cations, those result in a strong electrostatic interaction whose magnitude can be about 110-125 kJ‚mol -1 in the case of xylene molecules. 9 When shifting the cation from lithium to cesium, several parameters can change, inducing modifications in the overall adsorption strength of the molecules onto S II sites. First, as the size of the cation changes while bearing the same charge, it changes the cation polarizability and thus its electrophilic nature.…”

Section: Dynamic Adsorption Experiments Related To Henry's Lawmentioning

confidence: 99%

Selectivity of Thiophene/Toluene Competitive Adsorptions onto Zeolites. Influence of the Alkali Metal Cation in FAU(Y)

Laborde-Boutet

Joly

Nicolaos

et al. 2006

Ind. Eng. Chem. Res.

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In the framework of research considering adsorption for gasoline desulfurization purposes, dynamic adsorption experiments have been performed to study a comparison between thiophene and toluene affinities toward Y-faujasite adsorbents (Si/Al ) 2.4) exchanged with various alkali metal cations (Li + , Na + , K + , Rb + , Cs + ). These experiments have been carried out at two concentration ranges in liquid n-heptane solutions: around 25 mmol‚L -1 for competitive adsorptions and around 1.25 mmol‚L -1 for single-solute adsorptions. Complementary microcalorimetry studies have been carried out in order to investigate the interaction of nucleophilic compounds toward alkaline Y zeolites, by measuring the adsorption enthalpy of CCl 4 onto NaY and CsY sorbents. The results clearly exhibit two opposite trends for the adsorption of thiophene and toluene molecules onto alkaline Y faujasites. The thiophene affinity increases with cation electropositivity, while the toluene affinity decreases as the cations are more electropositive. Thus, from a favorable adsorption for toluene onto the LiY zeolite (R thio/tol ) 0.38 at ca. 26 mmol‚L -1 ), the selectivities shift in favor of thiophene so that the R thio/tol value reaches 3.00 with the CsY zeolite. The calorimetry measurements of CCl 4 adsorption have exhibited an increase of the adsorption enthalpy with more electropositive cations, which seems to indicate that thiophene molecules are adsorbed similarly to CCl 4 , i.e., by strong interaction between the nucleophilic S atom of thiophene and the cationic charge. However, toluene should be mainly stabilized on the adsorption sites through other interactions, as combined attractions between the H atoms of toluene and the O atoms of the zeolite framework surrounding the S II cation can be suggested.

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“…It was also reported that benzene is located in two distinct sites, one site is the S II cation via π electron density, and the other site is the circular windows that link together neighboring supercages through van der Waals forces. Xylenes attach through the aromatics π electron interaction on the cation of S II site, which is considerably stronger than the van der Waals forces . The aforementioned may explain the lower heat of adsorption of benzene.…”

Section: Resultsmentioning

confidence: 99%

Adsorption of C₆–C₈Aromatics over Ba‐Exchanged Zeolite X at High Temperature

et al. 2019

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The adsorption of C6–C8 aromatics was investigated at higher temperatures than normally used in the industry in the absence of water to assess the adsorption equilibrium properties under conditions that can be suitable for a simulated moving‐bed reactor for the production of p‐xylene. Batch experiments were conducted on a dry Ba‐exchanged zeolite X at various temperatures in the liquid phase. Pseudo‐single‐component adsorption equilibrium isotherms from binary mixtures with i‐octane were obtained based on the adsorbed amount with different initial concentrations. The Langmuir model was applied to describe the adsorption equilibrium data. The estimated parameters predicted very well the equilibrium in the adsorbent.

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Monte Carlo simulations on adsorptions of benzene and xylenes in sodium-Y zeolites

Cited by 27 publications

References 20 publications

Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Selectivity of Thiophene/Toluene Competitive Adsorptions onto Zeolites. Influence of the Alkali Metal Cation in FAU(Y)

Adsorption of C₆–C₈Aromatics over Ba‐Exchanged Zeolite X at High Temperature

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Monte Carlo simulations on adsorptions of benzene and xylenes in sodium-Y zeolites

Cited by 27 publications

References 20 publications

Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Multivariate and Multiscale Data Assimilation in Terrestrial Systems: A Review

Selectivity of Thiophene/Toluene Competitive Adsorptions onto Zeolites. Influence of the Alkali Metal Cation in FAU(Y)

Adsorption of C6–C8Aromatics over Ba‐Exchanged Zeolite X at High Temperature

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Adsorption of C₆–C₈Aromatics over Ba‐Exchanged Zeolite X at High Temperature