Mexico City, Mexico


Mexico City, Mexico
Time filter
Source Type

Robles-Gonzalez V.,ENCB IPN | Galindez-Mayer J.,ENCB IPN | Rinderknecht-Seijas N.,ESIQIE IPN | Poggi-Varaldo H.M.,Energy and Environmental Research Center
Journal of Biotechnology | Year: 2012

Mexican distilleries produce near eight million liters of mezcal per year, and generate about 90 million liters of mezcal vinasses (MV). This acidic liquid waste is very aggressive to the environment because of its high content of toxic and recalcitrant organic matter. As a result, treatment is necessary before discharge to water bodies. It is interesting, yet disturbing; verify that there is a significant gap on the treatment of MV. However, there is an abundant body of research on treatment of other recalcitrant toxic effluents that bear some similarity to MV, for example, wine vinasse, vinasses from the sugar industry, olive oil, and industrial pulp and paper wastewaters. The objective of this review is to critically organize the treatment alternatives of MV, assess their relative advantages and disadvantages, and finally detect the trends for future research and development. Experience with treatment of this set of residuals, indicates the following trends: (i) anaerobic digestion, complemented by oxidative chemical treatments (e.g. ozonation) are usually placed as pretreatments, (ii) aerobic treatment alone and combined with ozone which have been directed to remove phenolic compounds and color have been successfully applied, (iii) physico-chemical treatments such as Fenton, electro-oxidation, oxidants and so on., which are now mostly at lab scale stage, have demonstrated a significant removal of recalcitrant organic compounds, (iv) fungal pretreatment with chemical treatment followed by oxidative (O 3) or anaerobic digestion, this combination seems to give attractive results, (v) vinasses can be co-composted with solid organic wastes, particularly with those from agricultural activities and agro-industies; in addition to soil amenders with fertilizing value to improve soil quality in typical arid lands where agave is cultivated, it seems to be a low cost technology very well suited for rural regions in underdeveloped countries where more sophisticated technologies are difficult to adopt, due to high costs and requirements of skilled personnel. © 2011 Elsevier B.V.

Valor A.,ESIQIE IPN | Caleyo F.,ESIQIE IPN | Alfonso L.,National Autonomous University of Mexico | Vidal J.,University of Habana | Hallen J.M.,ESIQIE IPN
Corrosion | Year: 2014

The reliability and risk of non-piggable, corroding oil and gas pipelines can be estimated from historical failure data and through reliability models based on the assumed or measured number of corrosion defects and defect size distribution. In this work, an extensive field survey carried out in an upstream gathering pipeline system in Southern Mexico is presented. It has helped determine realistic values for the number of corrosion defects per kilometer (defect density) and obtain a better description of the corrosion defect size distributions in this system. To illustrate the impact that these new corrosion data can have on pipeline risk management, a reliability study is also presented where the field-gathered corrosion data have been used as input to a reliability framework for the estimation of the failure index of non-piggable pipelines and pipeline systems when different amounts of corrosion data are available. © 2014, NACE International.

Valor A.,IPN ESIQIE | Caleyo F.,IPN ESIQIE | Alfonso L.,National Autonomous University of Mexico | Velazquez J.C.,ESIQIE IPN | Hallen J.M.,IPN ESIQIE
Mathematical Problems in Engineering | Year: 2013

The stochastic nature of pitting corrosion of metallic structures has been widely recognized. It is assumed that this kind of deterioration retains no memory of the past, so only the current state of the damage influences its future development. This characteristic allows pitting corrosion to be categorized as a Markov process. In this paper, two different models of pitting corrosion, developed using Markov chains, are presented. Firstly, a continuous-time, nonhomogeneous linear growth (pure birth) Markov process is used to model external pitting corrosion in underground pipelines. A closed-form solution of the system of Kolmogorov's forward equations is used to describe the transition probability function in a discrete pit depth space. The transition probability function is identified by correlating the stochastic pit depth mean with the empirical deterministic mean. In the second model, the distribution of maximum pit depths in a pitting experiment is successfully modeled after the combination of two stochastic processes: pit initiation and pit growth. Pit generation is modeled as a nonhomogeneous Poisson process, in which induction time is simulated as the realization of a Weibull process. Pit growth is simulated using a nonhomogeneous Markov process. An analytical solution of Kolmogorov's system of equations is also found for the transition probabilities from the first Markov state. Extreme value statistics is employed to find the distribution of maximum pit depths. © 2013 A. Valor et al.

Oliver-Tolentino M.A.,UPIBI IPN | Arce-Estrada E.M.,UPALM | Cortes-Escobedo C.A.,Research Center e Innovacion Tecnologica Del | Bolarin-Miro A.M.,Autonomous University of the State of Hidalgo | And 3 more authors.
Journal of Alloys and Compounds | Year: 2012

In the present work, results of electrochemical evaluation, as well as morphological and structural characterization of Ni xW 1-x materials with x = 0.77, 0.64, 0.4, 0.19 and 0.07 processed by means of high energy ball milling from high purity powders are presented. Also, the electrocatalytic performance on the hydrogen evolution reaction (HER) of the Ni xW 1-x materials evaluated by linear polarization and cyclic voltammetry techniques in alkaline media at room temperature is discussed. The structural and morphological characterization of the as-prepared materials was carried out using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results indicated a small-particle clusters and solid solution formation. According to the kinetics parameters the best electrocatalytic activity was observed at Ni 64W 36. © 2011 Elsevier B.V. All rights reserved.

Garcia-Contreras M.A.,Instituto Nacional de Investigaciones Nucleares | Fernandez-Valverde S.M.,Instituto Nacional de Investigaciones Nucleares | Vargas-Garcia J.R.,ESIQIE IPN
Journal of New Materials for Electrochemical Systems | Year: 2011

CoNi and PtNi film electrocatalysts were prepared by Metal-Organic Chemical Vapour Deposition (MOCVD) and their electrocatalytic activity for the oxygen reduction reaction (ORR) in 0.5 M KOH was investigated by cyclic voltammetry and Rotating Disk Electrode techniques. Experiments included working electrodes of Co, Ni and Pt prepared also by MOCVD for comparison. The film electrocatalysts were characterized by X-ray diffraction, Scanning Electronic Microscopy and Energy dispersive X-ray analysis. Films thickness was about 200-250 nm and nanocrystallites were found in the range of 12 to 30 nm. In the same experimental conditions, the overpotential for the ORR at a current density of 1 mA cm-2 for PtNi film was 120 mV lower than the overpotential of Pt film electrocatalyst, and an enhanced activity was observed on PtNi with respect to Pt. The electrochemical response for the oxygen reduction reaction on CoNi film was higher than those of elemental Ni and Co films obtained by MOCVD. A good stability was obtained in a chronoamperometry test for the PtNi electrode, only affected by oxygen flow variations. © J. New Mat. Electrochem. Systems.

Valor A.,ESIQIE IPN | Caleyo F.,ESIQIE IPN | Hallen J.M.,ESIQIE IPN | Velazquez J.C.,ESIQIE IPN
Corrosion Science | Year: 2013

Different corrosion rate (CR) distributions have been derived from various corrosion growth models and used to perform reliability analyses of underground pipelines. The CR distributions considered in this work included a single-value distribution, based on the NACE-recommended CR for buried pipelines; a CR distribution derived from the Linear Growth corrosion model; Time-dependent and Time-independent CR distributions derived from a soil corrosion model; and a CR distribution derived from a Markov chain corrosion model. A Monte Carlo reliability framework capable of incorporating these CR distributions has been developed and applied to both synthetic and field-gathered corrosion data. The use of synthetic data assisted in evaluating the performance of each CR model with a consideration of corrosion defects of different sizes and ages. The application of the reliability framework to repeated in-line inspection data revealed the importance of careful selection of the CR distribution for an accurate assessment of the reliability of the inspected pipelines. It was shown that the best CR distribution is one that considers the ages and sizes of the corrosion defects as well as the observed dependence of the corrosion defect depth on time. Among the CRs considered in this study, the Markov chain-derived distribution was found to best satisfy these requirements. © 2012 Elsevier Ltd.

Sathish-Kumar K.,CINVESTAV | Solorza-Feria O.,CINVESTAV | Solorza-Feria O.,Hydrogen and Fuel Cells Group | Tapia-Ramirez J.,CINVESTAV | And 2 more authors.
International Journal of Hydrogen Energy | Year: 2013

In microbial fuel cells (MFCs) efficient extracellular electron transfer microbes, also known as anode-respiring bacteria, play an important role on cell performance. This type of microbes can be developed by application of enrichment procedures. The objective of this study was to compare a chemical (only C, final terminal electron acceptor Fe(III)), an electrochemical (only E), and a hybrid method (H, i.e., E followed by 3 serial transfers in iron (III) citrate medium) enrichment methods departing from a saline-sodic soil inoculum. In the electrochemical enrichment procedure in an electrolysis cell, the inoculum was subjected to a continuous electrical stress continually by posing the cell at -150 mV/SCE (+94 mV/SHE). The only C enrichment method delivered powers superior to the only E one (higher values of PAn,max = 49 mW m-2 and PV,max = 558 mW m-3 of C compared to 33 and 379 of only E). Interestingly, overall resistance as determined by EIS was lower for only E (1240 Ω) than for only C (1632 Ω). Yet, the hybrid H method, showed electrochemical characteristics consistently superior to both only C and only E methods (higher PAn,max and PV,max, lower internal resistance). Further detailed electrochemical studies of only E-method showed that the anodic resistance decreased with the time of operation of the electrolysis cell that would be consistent with the adaptability/ enrichment purpose of the method. Also, Cyclic voltammetry peaks with values close to those reported for bacterial cytochromes appeared with time of cell operation. To the best of our knowledge, this is the first time that it is reported that serial transfers with Fe(III) as electron acceptor to an inoculum previously enriched in an electrolysis cell, leads to improved characteristics of MFC and increased Fe(III)-reducing capability of the inoculum. Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Camposeco R.,Mexican Institute of Petroleum | Castillo S.,Mexican Institute of Petroleum | Mejia I.,Mexican Institute of Petroleum | Mugica V.,Metropolitan Autonomous University | And 5 more authors.
Catalysis Communications | Year: 2012

In this study we report the formation of nanocrystals and nanotubes of TiO 2 synthesized by the sol-gel method and hydrothermal treatment respectively. The obtained TiO 2 nanostructures were characterized by XRD, BET, TEM, UV-vis, XPS and FTIR; and evaluated in the CO oxidation. As for the nanotube-based samples, two catalysts were prepared (NTB5 and NTB10) through the hydrothermal treatment of nanosized titania in NaOH (5 and 10 N) at 160°C, followed by HCl rinsing until pH 1 was reached. From both catalysts, NTB10 showed the highest surface area (290 m 2/g), nanocrystals (15 nm) and stable phase (H 2Ti 3O 7) with a high CO oxidation capacity. We found that the band gap for NTB10 catalyst was of 2.85 eV, the lowest value respect to that of NTB5 and SGTB3 catalyst, based material (SGTB) showed both the lowest textural properties and catalytic performance. © 2011 Elsevier B.V. All rights reserved.

Loera-Serna S.,Metropolitan Autonomous University | Oliver-Tolentino M.A.,ESIQIE IPN | De Lourdes Lopez-Nunez M.,Metropolitan Autonomous University | Santana-Cruz A.,Metropolitan Autonomous University | And 4 more authors.
Journal of Alloys and Compounds | Year: 2012

For the construction of the metal-organic framework [Cu 3(BTC) 2] (commonly known as MOF-199 or HKUST-1), three different synthesis strategies were employed: room temperature stirring (RT), solvothermal (ST) and ultrasonic assisted (US); which afforded the desired material in moderate yields. Several characterization techniques (XRD, FT-IR, SEM and TGA) showed that HKUST-1 was obtained in every method. However, there were found interesting differences in functionalization depending on the synthesis conditions which produced the same [Cu 3(BTC) 2] host net but with different coordinative and bulk molecular guests. By XRD pattern analysis, it was possible to identify characteristic peaks of Cu 2O in the ST obtained material as secondary phase, showing that this methodology is quite harsh giving place to this product, although the [Cu 3(BTC) 2] complex was obtained in good yield. Regardless the energy source applied, in all three cases the desired [Cu 3(BTC) 2] MOF was obtained. In order to determine if the method of synthesis impacts directly on the electrochemical behavior of de material, applied cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) were investigated. The electrochemical results have shown that the resistance to the faradic process increases in the following order: Cu-MOF US, Cu-MOF RT and Cu-MOF ST. This behavior can be associated to the presence of Cu 2O in Cu-MOF ST. However, the synthesized MOF at room temperature showed a major content of copper, which could be electrochemically transformed, as well as purity, in comparison with those obtained by solvothermal and ultrasonic assisted methods. © 2012 Elsevier B.V. All rights reserved.

Vazquez-Larios A.L.,CINVESTAV | Poggi-Varaldo H.M.,CINVESTAV | Solorza-Feria O.,CINVESTAV | Rinderknecht-Seijas N.,ESIQIE IPN
International Journal of Hydrogen Energy | Year: 2015

This research aimed at evaluating the effect of inoculum type and the application of RuxMoySez as a cathode catalyst on the treatment and bioelectricity production of a microbial fuel cell (MFC) fed with a municipal leachate. The inocula assayed were a plain sulphate-reducing inoculum (In-SR), an enrichment in Mn(IV)-reducing bacteria (In-EMn(IV)), and two enrichments in Fe(III)-reducing bacteria, namely, In-EFe(III)-S and In-EFe(III)-SR. In the batch experiments where the cells were operated with the faces connected in parallel and loaded with an external resistance of 100 Ω, enriched inocula had a significant, positive effect of cell performance. The average volumetric powers PV-ave observed ranged from 2146 (In-SR) to 13 304 mW/m3 (In-EFe(III)-S). The highest value of PV-ave achieved in our work was about 30% of that of commercial anaerobic digestion of wastes. Application of inocula enriched in Fe(III) and Mn (IV)-reducing bacteria significantly improved the performance of cells that used RuxMoySez as a cathodic catalyst for the oxygen reduction reaction. © 2015 Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Loading ESIQIE IPN collaborators
Loading ESIQIE IPN collaborators