Gelacio Aguilar Armenta - Academia.edu (original) (raw)

Papers by Gelacio Aguilar Armenta

Langmuir, 2006

In this study, the adsorbents Cu +-3SiPPH723 and Cu 2+-3SiPPH723 were prepared starting from a si... more In this study, the adsorbents Cu +-3SiPPH723 and Cu 2+-3SiPPH723 were prepared starting from a silica-expanded zirconium phosphate heterostructure, 3SiPPH(0.2), which was subjected to an ion exchange with Cu(I) and Cu(II). These materials were characterized using powder X-ray diffraction, X-ray photoelectron spectroscopy, ammonia thermally programmed desorption, hydrogen temperature-programmed reduction, and N 2 adsorption (77 K). The equilibria and kinetics of adsorption of pure propylene (C 3 H 6) and propane (C 3 H 8) were studied using a conventional glass high-vacuum volumetric device, equipped with grease-free valves, in the temperature range of 273-393 K. The starting material, 3SiPPH(0.2), presented a high acidity and irreversible chemisorption of the olefin, which increases with temperature. Unlike the support, the irreversible adsorption of the olefin on the Cu +-3SiPPH723 and Cu 2+-3SiPPH723 samples decreases with increasing temperature and disappears at 393 K, showing a very high selectivity toward propylene. The C 3 H 8 adsorption in all the samples was always reversible. On the basis of the results of this study, both Cu +-3SiPPH723 and Cu 2+-3SiPPH723 samples can be efficiently applied in the separation of a C 3 H 6 / C 3 H 8 mixture at 393 K. Cu +-3SiPPH723 would have the highest efficiency, because its capacity for C 3 H 6 adsorption was higher than that for the Cu 2+-3SiPPH723 sample.

Journal of Sol-Gel Science and Technology, 2006

Journal of Porous Materials, 2007

... EI Basaldella (&) 4 JC Tara Centro de Investigación y Desarrollo en Ciencias Aplicada... more ... EI Basaldella (&) 4 JC Tara Centro de Investigación y Desarrollo en Ciencias Aplicadas Dr Jorge J. Ronco, CINDECA (CONICET-CIC-UNLP), 47 No. ... 38, 3614 (1999) 2. RT Yang, ES Kikkinides, AIChE J. 41, 509 (1995) 3. LS Cheng, RT Yang, Adsorption 1, 61 (1995) 4. SU Rege ...

Journal of Chemical & Engineering Data, 2010

The adsorption kinetics and equilibria of pure carbon dioxide (CO 2), ethylene (C 2 H 4), and eth... more The adsorption kinetics and equilibria of pure carbon dioxide (CO 2), ethylene (C 2 H 4), and ethane (C 2 H 6) on 4A(CECA) commercial zeolite have been measured over the temperature range T) (293.15 to 353.15) K using a glass-vacuum volumetric device. The adsorption rates of the gases were measured automatically via a custom acquisitions data card that was capable of registering pressure and time (t) data five times per second in the first period for t) (0 to 180) s, simultaneously. All of the gases showed a decreasing adsorption affinity and isosteric heat of adsorption in the order CO 2 > C 2 H 4 > C 2 H 6. Unlike CO 2 , an activated diffusion for C 2 H 4 and C 2 H 6 for low t was observed. The adsorption activation energy for ethane E a) (14.6 (0.2) kJ • mol-1 was found to be slightly higher than that for ethylene E a) (13.8 (1) kJ • mol-1. The dual Langmuir model described the CO 2 adsorption isotherms, whereas those for C 2 H 4 and C 2 H 6 were fitted with the Sips equation at (293.15 and 323.15) K. The three gases were reversibly adsorbed, and the adsorption selectivity for gas binary mixtures decreased in the sequence CO 2 /C 2 H 6 > C 2 H 4 /C 2 H 6 > CO 2 /C 2 H 4. The obtained results indicate that 4A(CECA) zeolite could be a good candidate for separating these binary gas mixtures at 293.15 K.

Abstract. We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass h... more Abstract. We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass high-vacuum volumetric system that permitted characterization of the energetics of the adsorption pro-cess. Adsorption equilibrium data were analyzed using the classical Freundlich equation and the Dual–Langmuir model. We employed the Clausius–Clapeyron relationship to calculate the isosteric heats of adsorption using the equilibrium data of the isotherms measured at 273.15 K and 293.15 K. The isosteric heats of reversible adsorp-tion of both gases were smaller than the heats of total adsorption. The interaction energy of N2O with mordenite was larger than the interac-tion energies of N2O with either erionite or clinoptilolite. The interac-tion energy of NO was found to be largest with erionite.

Separation Science and Technology, 2009

The capacity of natural zeolites (ZAPS, ZNT, and ZSL) to adsorb N2O and NO in both static and dyn... more The capacity of natural zeolites (ZAPS, ZNT, and ZSL) to adsorb N2O and NO in both static and dynamic regimes was studied experimentally. It was found that the cations present in the zeolites act as centers of adsorption for both gases, suggesting their competitive adsorption. However, a considerable difference was observed among the capacities of the zeolites to adsorb these

Journal of Chemical Technology & Biotechnology, 2004

This work investigated the ion exchange of ammonia on clinoptilolite obtained from mineral deposi... more This work investigated the ion exchange of ammonia on clinoptilolite obtained from mineral deposits located in San Luis Potosi and Sonora, Mexico. Experimental ion exchange isotherm data were obtained in a batch adsorber. The effects of temperature and solution pH on the ion exchange capacity were studied and it was found that the exchange capacity was slightly increased by augmenting the temperature and by decreasing the pH from 6 to 3. The ion exchange capacity was independent of the diameter of the zeolite particles. The reversibility of ion exchange was analyzed by desorbing the ammonia exchanged on the zeolite. The ion exchange was reversible when 1% NaCl solution was used as the desorbing solution, but more ammonia was desorbed using 1% KCl solution in the desorption step. It was concluded that a considerable amount of ammonia was exchanged on the clinoptilolite and that the exchange capacity was slightly dependent on the temperature and pH.

The Journal of Physical Chemistry B, 2001

The rate of adsorption of pure CO 2 , O 2 , N 2 , and CH 4 on natural untreated clinoptilolite-ri... more The rate of adsorption of pure CO 2 , O 2 , N 2 , and CH 4 on natural untreated clinoptilolite-rich volcanic tuff (Cp) from Tehuacan (Puebla, Mexico), and on cation-exchanged clinoptilolite samples (Ca-Cp, K-Cp, and Na-Cp) has been measured at 20°C using a glass high-vacuum volumetric apparatus. The X-ray diffraction pattern of Cp showed that the main crystalline phases correspond to clinoptilolite-heulandite and minor amounts of mordenite, cristobalite, feldspar (albite), quartz, smectite, and opal. The adsorption rates of gases in the initial period (t < 180 s) were measured with a custom acquisition data card capable of registering pressure and time data five times per second, simultaneously. The influence of cation exchange on adsorption kinetics of the gases depended on the gas-adsorbent contact time (t). In the initial period, the adsorption rate of all gases on all samples decreased in the order Ca-Cp > K-Cp > Cp > Na-Cp, and the affinity decreased in the order CO 2. N 2 > O 2 > CH 4 , whereas at equilibrium (t f ∞ s) the adsorption uptake decreased in the sequence CO 2. CH 4 > N 2 > O 2. The slow adsorption of methane in Na-Cp was probably due to diffusional difficulties as a result of channel blockage by Na + cations. By cation exchange of Cp an adsorbent can be tailored for the separation of N 2 /O 2 , N 2 /CH 4 , and CO 2 /CH 4 mixtures.

The results of the porosity study of three samples of co - mmercial activated carbons, from adsor... more The results of the porosity study of three samples of co - mmercial activated carbons, from adsorption isotherms of benzene (295 K) and N 2 (75.5 K), using a high volumetric system, which was made of Pyrex glass, are presented. Special care was taken in the measurement of the isotherms in the range of low relative pressures (10-6) in order

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2001

The method of adsorption of N 2 (77 K) and hydrocarbon C 6 (295 K) has been used to study the por... more The method of adsorption of N 2 (77 K) and hydrocarbon C 6 (295 K) has been used to study the porous structure of two Mexican natural adsorbents: ANAVE and ZAPS. It was established that ANAVE is a mesoporous adsorbent, and ZAPS is essentially microporous with :85% of micropore contents. The micropore volume (Dubinin) coincides with the capacity of Langmuir monolayers. The microporous structure also was characterized by t-method, ''film surface area method'', and chromatographic separation tests of the atmospheric air and the mixture of n-hexane, cyclohexane and benzene. It was established (XRD) that the principal crystalline phase in ZAPS corresponds to the erionite and that this natural adsorbent can be applied in processes of great practical interest, such as the separation of n-paraffin from cyclic and aromatic hydrocarbons. The sample ANAVE is a non-crystalline material (XRD).

REVISTA de la SOCIEDAD, 2001

Resumen. En este trabajo se informa de los resultados del estudio de la capacidad que presenta la... more Resumen. En este trabajo se informa de los resultados del estudio de la capacidad que presenta la zeolita natural ZAPS (erionita), así como la premodificada con K + (ZAPS-K), de adsorber propano y propileno a t ≥ 20 °C. La medición de la cinética e isotermas de equilibrio de adsorción se realizó en un sistema volumétrico de alto vacío, construido en vidrio Pyrex y equipado con válvulas libres de grasa. Se estableció que en ZAPS, el C 3 H 6 se adsorbe en mayores cantidades que el C 3 H 8 , debido a la contribución del enlace π en la energía total de interacción. La muestra ZAPS-K presentó menor capacidad de adsorción que ZAPS y a diferencia de la ZAPS, la adsorción de ambos hidrocarburos y de C 3 H 6 en 4A aumenta al aumentar la temperatura. Palabras clave: Isoterma de adsorción, cinética de adsorción, erionita, propano, propileno.

Adsorption Science & Technology, 2009

As a means of assessing their possible applications in the separation and purification of the gas... more As a means of assessing their possible applications in the separation and purification of the gases concerned, the adsorption kinetics and equilibrium of pure ethylene (C 2 H 4), ethane (C 2 H 6) and carbon dioxide (CO 2) onto untreated natural clinoptilolite/heulandite volcanic tuff (Cp) from Villa de Reyes (San Luis Potosí, México) and onto cation-exchanged clinoptilolite samples (Cp-H and Cp-Na) have been measured over the temperature range 0-240 ºC using a glass high-vacuum volumetric device. Some of the results have been compared with those obtained on a commercial synthetic zeolite 4A (CECA). The adsorption rates of the various gases were measured automatically via a custom acquisition data card capable of registering pressure and time data simultaneously. All the samples showed a decreasing adsorption affinity in the order CO 2 > C 2 H 4 > C 2 H 6. A very slow adsorption process and a large proportion of irreversible adsorption were observed for both hydrocarbons onto Cp at 20 ºC. The irreversible adsorption of C 2 H 4 decreased with increasing temperature, with a small irreversible adsorption being detected at 240 ºC. Both Cp at 240 ºC and Cp-Na at 0 ºC could be promising adsorbents for the separation of C 2 H 4 /C 2 H 6 mixtures, while Cp-H may be recommended for the separation at 20 ºC at times less than 100 s. The high adsorption selectivity toward CO 2 of Cp and Cp-Na at all the experimental temperatures studied enables these samples to be recommenced for the purification of C 2 H 4 and C 2 H 6 contaminated with CO 2 .

We studied the capacity of activated carbon (C1) to adsorb NO at different temperatures using a g... more We studied the capacity of activated carbon (C1) to adsorb NO at different temperatures using a glass, high-vacuum volumetric system to obtain information on the energy characteristics of the adsorption process. Adsorption equilibrium data were analysed by the Freundlich isotherm equation using regression analysis. We employed the Clausius-Clapeyron relationship to calculate the isosteric heats of NO adsorption using the equilibrium data of the isotherms measured at 273 and 293 K. The amount of NO adsorbed during reversible adsorption was higher than that adsorbed during total adsorption, probably due to semiquinones formation during total adsorption, which increased both the adsorption capacity of NO and adsorbate-adsorbent interactions during reversible adsorption.

El presente estudio reveló algunos resultados muy interesantes en lo que se refiere a las interac... more El presente estudio reveló algunos resultados muy interesantes en lo que se refiere a las interacciones colaterales moléculamolécula de la olefina adsorbida en el sólido, estableciéndose que en condiciones subcríticas de temperatura, las propias moléculas de propileno (C 3 H 6), adsorbidas irreversiblemente, juegan el papel de centros activos para la adsorción subsiguiente. La medición de la cinética de adsorción de los hidrocarburos puros se realizó a distintas temperaturas en un sistema volumétrico de alto vacío. Se observó que en la muestra 5A-K, el proceso de la adsorción de C 3 H 6 es de tipo activado, mientras que la cantidad adsorbida de propano (C 3 H 8) es muy baja y totalmente reversible. Con base en los resultados obtenidos se supone que la muestra 5A-K puede ser un excelente adsorbente para la separación de mezclas C 3 H 6 /C 3 H 8 a la temperatura de 150º C.

Journal of the Mexican Chemical Society, 2019

We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass high-vacuum... more We studied the capacities of three natural zeolites to adsorb N2O or NO using a glass high-vacuum volumetric system that permitted characterization of the energetics of the adsorption process. Adsorption equilibrium data were analyzed using the classical Freundlich equation and the Dual–Langmuir model. We employed the Clausius–Clapeyron relationship to calculate the isosteric heats of adsorption using the equilibrium data of the isotherms measured at 273.15 K and 293.15 K. The isosteric heats of reversible adsorption of both gases were smaller than the heats of total adsorption. The interaction energy of N2O with mordenite was larger than the interaction energies of N2O with either erionite or clinoptilolite. The interaction energy of NO was found to be largest with erionite.

Se estudió la capacidad que presentan las zeolitas naturales mexicanas erionita (ZAPS), mordenita... more Se estudió la capacidad que presentan las zeolitas naturales mexicanas erionita (ZAPS), mordenita (ZNT) y clinoptilolita (ZN-19), de adsorber CO2 a t £ 27 °C. La medición de las isotermas de adsorción se realizó en un sistema volumétrico de alto vacío, construido en vidrio Pyrex y equipado con válvulas libres de grasa. Se estableció que en la erionita, el CO2 se adsorbe en mayores cantidades que en la mordenita y la clinoptilolita, debido a que la primera posee una densidad catiónica y volumen de microporo mayor que las otras dos muestras. La muestra ZAPS presentó el mayor de los calores isostéricos de adsorción total, debido a que esta muestra puede poseer una heterogeneidad energética superficial mayor que las otras muestras. Las muestras ZAPS, ZNT y ZN-19 provienen de yacimientos ubicados en los estados de Sonora, Tamaulipas y San Luis Potosí, respectivamente.

Journal of the Mexican Chemical Society

En este trabajo se estudió la cinética de adsorción de CO2, N2 y CH4 puros a 20 °C en clinoptilol... more En este trabajo se estudió la cinética de adsorción de CO2, N2 y CH4 puros a 20 °C en clinoptilolita natural (ZSL), proveniente de Villa de Reyes, San Luis Potosí, México, y en muestras de clinoptilolita cambiadas parcialmente con Na+, K+, Ca2+y H+(ZSL-Na, ZSL-K, ZSL-Ca, ZSL-H), utilizando un sistema volumétrico de alto vacío. La capacidad de adsorción que presentaron las muestras ZSLNa, ZSL-K, ZSL-Ca y ZSL de adsorber estos gases, a tiempos bajos de contacto, disminuyó en el orden CO2 > N2 > CH4 , mientras que en la muestra ZSL-H disminuyó en la secuencia CO2 > CH4 > N2 . Las muestras ZSL-Ca y ZSL-Na pueden ser recomendadas para la separación de mezclas CO2 / CH4 y N2 / CH4

Langmuir, 2002

In this study, the adsorption equilibria and kinetics of pure propane (C3H8) and propylene (C3H6)... more In this study, the adsorption equilibria and kinetics of pure propane (C3H8) and propylene (C3H6) on natural erionite (ERI), from Agua Prieta (Sonora, Mexico), and on cation-exchanged erionite samples (K-ERI and Ag-ERI) have been measured at different temperatures using a glass high-vacuum volumetric device. All of the samples showed selectivity toward propylene. The ion-exchange treatment influenced, remarkably, the C 3H8 and C3H6 adsorption behaviors. The adsorbed amounts of both hydrocarbons on K-ERI and Ag-ERI samples were lower than those on ERI, a result that can be ascribed to a decrease in micropore volume. It was established that the adsorptive separation of these gases on K-ERI could be effected most efficiently at 111°C for gas-adsorbent contact times in the range 20-100 s, whereas the Ag-ERI sample could be recommended for this separation for the temperature range 50-80°C and for short gas-adsorbent contact times in the interval 10-30 s.

Industrial & Engineering Chemistry Research, 1999

The characterization of the porosity of three samples of commercial activated carbons, from adsor... more The characterization of the porosity of three samples of commercial activated carbons, from adsorption isotherms of N 2 (77 K), obtained by the volumetric method are presented. Special care was taken in the measurement of the isotherms in the range of low relative pressures (10-6) in order to characterize the microporosity of these carbons by different approaches: Dubinin-Radushkevich (D-R), R plots, Jaroniec-Choma (J-Ch), and Pfeifer et al. Microporosity characterization was completed by measurement of the specific surface area (BET) of the adsorbents in which different amounts of benzene at 295 K had been preadsorbed. It was established that the three samples are basically microporous, with a strongly pronounced structural and energetic heterogeneity.

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2004

The kinetics of adsorption of pure propylene (C 3 H 6) and propane (C 3 H 8) on a commercial zeol... more The kinetics of adsorption of pure propylene (C 3 H 6) and propane (C 3 H 8) on a commercial zeolite sample 4A (CECA), provided by the company CECA, has been measured in the temperature range of 20-185 • C using a high-vacuum volumetric glass device. For temperatures below the critical temperature of C 3 H 6 (<92 • C), especially at 20 • C and with long contact times, a certain amount of irreversibly adsorbed C 3 H 6 was observed, whereas for temperatures above the critical temperature the irreversibly adsorbed amount of propylene was extremely small. The isosteric heat of adsorption for C 3 H 6 was also evaluated. Unlike the C 3 H 6 , the adsorbed amount of C 3 H 8 on the 4A (CECA) sample at low and high temperatures was negligible and totally reversible. These results allow the assumption that this sample could be an excellent adsorbent for the molecular sieve separation of C 3 H 6 /C 3 H 8 mixtures in the temperature range of 150-185 • C.