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Chavez R.-H.,Instituto Nacional de Investigaciones Nucleares | Guadarrama J.J.,Toluca Institute of Technology
Clean Technologies and Environmental Policy | Year: 2015

This paper presents the characterization of ashes generated from different incineration processes, such as (a) coupled kilns, (b) conventional kiln, (c) wood, and (d) fly and bottom of Petacalco power plant, in order to set which is the best one for the purification of biogas from landfill. The techniques employed for the characterization were scanning electron microscopy, X-ray diffraction, and transmission electron microscopy. The ashes from these sources were analysed through their microstructural properties and features such as the efficiency of carbon dioxide reduction due to chemical reaction with the calcium oxide present in the ashes. Calcium carbonate mineral was obtained as a highly stable and insoluble salt. The results indicate that the ash from wood is the most appropriate to reduce the carbon dioxide due to its high calcium content. Dry fly ash from Petacalco power plant has the ability to carry out a process of carbonation according to the samples analyzed. It was noted that elements such as aluminium, sodium, potassium, and magnesium led to the formation of some other mineral species in the ash resulting from incineration processes. © Springer-Verlag Berlin Heidelberg 2015.

Chavez R.-H.,Instituto Nacional de Investigaciones Nucleares | De J. Guadarrama J.,Toluca Institute of Technology
Chemical Engineering Transactions | Year: 2011

The purpose of this work is to simulate CO2 capture process, using Monoethanolamine (MEA) at 30 % weight, at power plant and using Aspen Plus™ simulator. CO2 is removed by chemical absorption processes from the flue gases of the power plant. The main challenge of the chemical absorption CO2 capture processes is reducing the energy requirement in the stripper which has contributors from reboiler energy consumption and maximum CO2 absorption. This work presents an enhancement the structured packing study in separation columns: ININ 18, Sulzer BX and Mellapak 250Y, and the advance of CCS technologies (CO2 capture and sequestration). This ININ 18 material was developed by the Mexican National Institute of Nuclear Research (ININ by its acronym in Spanish). The parameters studied were: Separation absorption efficiency, flow ratio (L/G) values in order to find the load or turbulence regimen in absorption process, reboiler duty at desorption column, and column diameters at different treated flue gas flows. The results showed that Sulzer BX had the highest volumetric mass transfer coefficient values and the lowest height of mass transfer equivalent unit, with 3.76 s-1 and 0.317 m, respectively, with 600 t/h flue gas flow, and the paper discusses the selection of most important parameters necessary to obtain 90 % capture rate and the lowest energy consumption for CO2 capture plants in comparison with respect to the other two packings. Sulzer BX packing shows decreased reboiler energy consumption with 8.5 MJ/kg CO2. Copyright © 2011, AIDIC Servizi S.r.l.

Chavez R.-H.,Mexican National Institute of Nuclear Research ININ | de J. Guadarrama J.,Toluca Institute of Technology
Chemical Engineering and Technology | Year: 2012

The degree of CO 2 absorption by monoethanolamine (MEA) using metal structured packing material, ININ18, was studied. The aqueous solution contained 30wt-% MEA in countercurrent with CO 2 flue gas. The capture process was carried out in an absorption column with dimensions 4.0m in height and 0.3m in diameter. The mass transfer coefficient and height of mass transfer were evaluated. Results show a volumetric mass transfer coefficient of 3.76s -1, a height of mass transfer equivalent unit of 0.317m, and an absorption efficiency of 90% from flue gas. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lopez-Lagunas A.,Toluca Institute of Technology
Journal of Signal Processing Systems | Year: 2011

High performance portable systems for real-time video/image analysis continue to demand high processing power and memory bandwidth. In embedded systems such as digital still cameras, camcorders, and camera phones, the expected performance must be delivered while meeting size, weight, and power constraints. A well-designed system should include analyses of its memory subsystem as well as the computation platform. This paper focuses on a streaming memory subsystem that leverages deterministic memory access patterns. We formalize the notion of stream descriptors as a means to define these stream access patterns and to improve memory access efficiencies by discovering locality between different data streams. Data movement for a real-time image analysis applications are performed, showing favorable bandwidth savings using stream descriptors. © 2009 Springer Science+Business Media, LLC.

Baeza-Alvarado M.D.,Instituto Nacional de Investigaciones Nucleares | Baeza-Alvarado M.D.,Toluca Institute of Technology | Baeza-Alvarado M.D.,S.A. de C.V. | Olguin M.T.,Instituto Nacional de Investigaciones Nucleares
Microporous and Mesoporous Materials | Year: 2011

The kinetics of the removal of Ba2+ and fulvic acid by a surfactant-modified Mexican clinoptilolite-rich tuff was investigated. The effect of fulvic acid in a bi-component aqueous medium (Ba2+-fulvic acid) on the sorption of Ba2+ was also considered, and an unmodified zeolitic material was included for comparison. The Ba2+, fulvic acid and fulvic acid-Ba2+ solutions were placed in contact with a Mexican clinoptilolite-rich tuff in a batch system. Atomic absorption and UV-Vis spectroscopy were used to measure the remaining aqueous barium and fulvic acid, respectively. The Ba2+ and fulvic acid sorption kinetic experimental data were best fitted by a pseudo-second-order model. The amount of surfactant covering the surface of the zeolitic material and the fulvic acid influenced the sorption kinetics of Ba2+ from aqueous media by sodium and surfactant-modified Mexican clinoptilolite-rich tuffs. The presence of Ba 2+ in the aqueous medium increased the sorption of fulvic acid by the sodium-modified zeolite from Oaxaca (NaZO), but the time to reach equilibrium was greater. The Ba2+ was removed from aqueous media by ion exchange or complexation with fulvic acid, and fulvic acid was adsorbed by the surfactant-modified zeolites through a partitioning mechanism. © 2010 Elsevier Inc. All rights reserved.

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