Adsorption equilibrium and kinetics of H2O on zeolite 13x

Ryu, Young Ki; Lee, Seung‐Ju; Kim, Jong Wha; Leef, Chang-Ha

doi:10.1007/bf02698301

Cited by 52 publications

(43 citation statements)

References 5 publications

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“…layered bed While the equilibrium isotherm of water in the zeolite 13X was highly favorable, similar to that in zeolite 5A, in the experimental range of this study, the isotherm in the silica gel Ž . was close to a linear type Yang, 1987;Ryu et al, 2001 . The adsorption capacity of the silica gel for water was superior to that of the zeolite 13X, where the RH was higher than 55%.…”

Section: Resultsmentioning

confidence: 73%

Adsorption dynamics of water in layered bed for air‐drying tsa process

Ahn

Lee

2003

AIChE Journal

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Ž. The thermal swing adsorption TSA process is most commonly used to prevent the air contamination from organic solvents of low concentration and to dehumidify gases. Specifically, the air drying by the TSA process is one of the major commercial gas separation processes.Since the regeneration step in the TSA cycle requires time enough to heat and cool the bed, it is often the time-limiting step in the TSA cycle. In the design and economic assessment of the TSA process, one is principally interested in energy consumption involved with regeneration time, purge gas requirements, and heat load. The equilibrium theory has been widely used to obtain exact solutions from coupled mass and energy balances. In this case, due to the assumption of instantaneous mass-and heat-transfer rates, the predicted concentration and temperature profiles were sharper than the Ž experimental results Kumar and Dissinger, 1986; Schork and . Fair, 1988 . However, in the numerical method, the mass and energy balances are solved with the equations describing the mass-and heat-transfer rates. Although this approach has a limit resulting from computational difficulty, it has become a general method to solve the coupled differential equations. Ž . Basmadjian et al. 1975 studied the hot nitrogen regeneration of carbon dioxide in the activated carbon bed by using Ž . an adiabatic model. Carter and Husain 1974 have carried out both experiment and simulation of the adsorption breakthrough of carbon dioxide and water with helium as a carrier gas in a fixed bed. They found that a surface or capillary flow of adsorbate occurs in the adsorbed phase transport in addition to macropore diffusion. Also, the adsorption and desorption of ethane and propane mixtures on activated carbon by using a nonisothermal model with Flory-Huggins solution Ž . theory FH-VSM and a rate model considering Knudsen and Ž . surface diffusions in parallel Huang and Fair, 1988 . Davis Ž . and LeVan 1987 showed that adiabatic fixed-bed adsorption cycles with adsorption, heating, and cooling steps were analyzed by using simple wave theory.Although the air-drying TSA process is commonly used in industry, there has been little fundamental research to imCorrespondence concerning this article should be addressed to C.-H. Lee. prove an understanding of the process. Moreover, an extensive literature on adsorber analysis has been published, but relatively few theoretical analyses have been done on regen-Ž . eration Yang, 1987;Ruthven et al., 1994 . However, it is usually the regeneration step that determines the economic success of the TSA process, because it consumes a huge amount of energy for regeneration. Therefore, the improvement of the regeneration process through the minimization of energy consumption can contribute to the design and optimization methods of the TSA process. In addition, Yang and Ž . Lee 1998 studied the adsorption dynamics of a layered bed for the purpose of developing a H PSA process from coke 2 oven gas. The performance of the PSA process could be impr...

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Section: Resultsmentioning

confidence: 73%

Adsorption dynamics of water in layered bed for air‐drying tsa process

Ahn

Lee

2003

AIChE Journal

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“…Such a relation is known as adsorption kinetics (dynamics). There are many basic kinetics models, which include frequently used kinetics models such as pseudo first-and second-orders, Elovich and intraparticle diffusion models (Alam et al, 2007;Oke et al, 2008;Yasmin et al, 2009;Ho and McKay, 1999b); solid diffusion, driving force, Vermeule; and Nakao and Suzuki models (Ryu et al, 2001); zero order, first-order, second-order, and fractional power (Yasmin et al, 2009). Figure 7a and b presents relationship between concentration of Cd 2+ remaining in solutions and time.…”

Section: Ion Exchange Modelmentioning

confidence: 99%

Adsorption kinetics of cadmium ions onto powdered corn cobs

et al. 2009

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Environmental pollution caused by the presence of toxic materials such as cadmium is becoming global problem and concern. This paper presents a report on kinetics of Cd 2+ removal from aqueous solutions through adsorption using powdered corn cobs (PCC). Corn cobs were collected from a selected location, washed to remove sand, air dried, ground and sieved into different particle sizes. The selected properties of PCC were determined using acid digestion method. Adsorption capacities through kinetics of Cd 2+ removal from synthetic solutions, typical raw water and domestic-institutional wastewater were studied. Effects of pH, PCC particle size, initial concentration of Cd 2+ and temperature on adsorption capacities were monitored through pseudo first-and second-order models, Elovich and intraparticle diffusion models to present adsorption rate parameters.The study revealed that PCC contained 86.89% volatile solids, had 4.56% acid solubility, 0.52 water solubility and 2.33% ash content. PCC removed Cd 2+ from aqueous solutions (synthetic, raw water, and wastewater). The relationship between time and concentration of Cd 2+ remaining in the solution followed exponential functions with squared correlation coefficient ranging from 0.9928 to 0.9993, 0.8701 to 0.9284, and 0.8514 to 0.9290 for synthetic solution, raw water, and typical domestic-institutional wastewater, respectively. Mechanism of cadmium adsorption onto PCC was in two separate stages linear portions in the first parts, while the final parts are curves indicating intraparticle diffusion. It was concluded that PCC is an effective adsorbent for Cd 2+ removal. The estimated production cost was 0.068 USD as against 0.50, 2.12, and 3.12 USD for producing adsorbents from empty fruit bunches; pencom shell and sugar cane based activated carbons, respectively.Cet article présente un rapport sur la cinétique du retrait du Cd2+ de solutions aqueuses par adsorption en utilisant de la rafle de maïs en poudre (RMP). Lesépis de maïs ontété collectésà partir d'un lieu sélectionné, lavés pouréliminer le sable, séchésà l'air, broyés et tamisés en particules de différentes tailles. Les propriétés sélectionnées de la RMP ontété déterminées en utilisant la méthode de la digestion acide. On aétudié les capacités d'adsorption par la cinétique du retrait du Cd2+ de solutions synthétiques, d'eaux brutes non traitées et d'eaux usées ménagères-institutionnelles. Les effets du pH, de la taille des particules de RMP, de la concentration initiale de Cd2+ et de la température sur les capacités d'adsorption ontété suivis par des modèles de pseudo-cinétique de premier ordre et de second ordre, Elovich et des modèles de diffusion intra-particule pour présenter des paramètres de taux d'adsorption. L'étude révèle que la RMP contenait 86,889% de solides volatils, avait une solubilité dans l'acide de 4,56%, une solubilité dans l'eau de 0,52 et une teneur en cendres de 2,331%. La RMP permettait de retirer le Cd2+ des solutions aqueuses (synthétiques, eau brute et eaux usées). La relation entre le...

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“…Highly humid environments provide favorable environments for fungi, harmful bacteria and house dust mites to grow, and destroy the heat-humidity balance of the human body, etc. [12]. Therefore, the demand for controlling the humidity and development of high efficiency sorbent technology has led to a great interest in new porous materials, especially microporous materials [13].…”

Section: Introductionmentioning

confidence: 99%

Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

et al. 2020

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The influence of the compensating cation (Na+, Li+, Mg2+) nature on the water adsorption properties of LTA and FAU-type zeolites was investigated. Cation exchanges were performed at 80 °C for 2 h using 1 M aqueous solutions of lithium chloride (LiCl) or magnesium chloride (MgCl2). XRF and ICP-OES analyses indicate that the cation exchange yields reach values between 59 to 89% depending on the number of exchange cycles and the nature of the zeolite and cation, while both zeolites structures are preserved during the process, as shown by XRD and solid state NMR analyses. Nitrogen adsorption-desorption experiments indicate a higher available microporous volume when sodium cations are replaced by smaller monovalent lithium cations or by divalent magnesium cations because twice less cations are needed compared to monovalent cations. Up to 15% of gain in the available microporous volume is obtained for FAU-type zeolites exchanged with magnesium cation. This improvement facilitates the adsorption of water with an increase in the water uptake up to 30% for the LTA and FAU type zeolites exchanged with magnesium. These exchanged zeolites are promising for uses in water decontamination because a smaller amount is needed to trap the same amount of water compared to their sodium counterparts.

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Adsorption equilibrium and kinetics of H2O on zeolite 13x

Cited by 52 publications

References 5 publications

Adsorption dynamics of water in layered bed for air‐drying tsa process

Adsorption dynamics of water in layered bed for air‐drying tsa process

Adsorption kinetics of cadmium ions onto powdered corn cobs

Influence of the Compensating Cation Nature on the Water Adsorption Properties of Zeolites

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