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262 results on '"Llanos, Javier"'

12. Coupling of electrodialysis and bio‐electrochemical systems for metal and energy recovery from acid mine drainage.

Author

Delgado, Yelitza, Llanos, Javier, and Fernández‐Morales, Francisco Jesus

Subjects
ACID mine drainage, MICROBIAL fuel cells, ELECTROFORMING, MICROBIAL cells, ELECTRIC power production, ELECTRODIALYSIS
Abstract

BACKGROUND: This work studied the treatment of a synthetic sphalerite acid mine drainage (AMD). The treatment was carried out by means of a previous concentration stage using electrodialysis, followed by electrodeposition using a bioelectrochemical system (BES). RESULTS: The best concentration results were obtained when operating the electrodialysis at 8 V and at a diluate/concentrate volume ratio of 3. This treatment yielded a concentrate fraction of about 25% of the volume and a clear fraction of about 75% of the volume. The concentrated fraction was treated in a BES for the electrodeposition of the metal contained. By operating a microbial fuel cell (MFC), the spontaneous reactions took place and, in 2 days, all the Fe3+ was reduced to Fe2+; then, all the Cu2+ was electrodeposited as pure Cu0 in about 8 days. The maximum current density attained in this stage was 0.1 mA cm−2 and the maximum power was 0.05 W cm−2. Then, a subsequent operation of a microbial electrolysis cell (MEC) allowed for the simultaneous recovery of the Fe2+, Ni2+, Zn2+, and Cd2+ as a mixed metal mass. CONCLUSION: The electrodialysis yielded a clear effluent representing 75% of the total volume and a concentrated effluent accounting for 25%. It was possible to treat the concentrated effluent in an MFC, recovering pure Cu0 with a net electricity generation. The non‐spontaneous metal reductions were subsequently accomplished by means of MEC, the electricity requirements being lower than those in the case of the raw AMD due to the higher mass transfer rate and the reduction of the Ohmic loses. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Published
2024
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17. Enhancing the Teaching of Corrosion to Chemical-Engineering Students through Laboratory Experiments

Author

Llanos, Javier, Pérez, Ángel, and de Lucas-Consuegra, Antonio

Abstract

This work presents a laboratory to help chemical-engineering students understand the basic concepts of corrosion. This laboratory has been performed since academic year 2011-2012 in the framework of the subject "Design of equipment and installations" for the third year of the Chemical Engineering Degree of the University of Castilla-La Mancha (Spain). It is based on calculating the corrosion rates of six different samples in order to evaluate the effects of the corrosion environment, the material of the sample, and the application of corrosion-prevention methods. The performance of the laboratory to enhance the teaching-learning methodology was evaluated by asking the students to answer a test before and after completing the laboratory. The results show that the laboratory improves the understanding of the students and also their confidence in their answers, although room for improvement was found in relation to the application of corrosion-prevention methods, for which corrective actions are proposed.

Published
2019
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18. Harnessing Lignocellulosic Waste‐Derived Carbon Materials for Green Electrochemical Applications.

Author

Ramírez, Álvaro, Muñoz‐Morales, Martín, López‐Fernández, Ester, and Llanos, Javier

Subjects
MICROBIAL fuel cells, LIGNOCELLULOSE, SOIL remediation, CARBON-based materials, CONSTRUCTED wetlands
Abstract

Phytoremediation and constructed wetlands are widely employed processes for the decontamination of soils and waters. These sustainable, effective, and cost‐efficient technologies rely solely on the use of plants. However, the application of these processes results in the accumulation of lignocellulosic residues, like it occurs with natural wetlands, which present a significant challenge due to the potential entry into the food chain of the adsorbed pollutants or the risk of initiating uncontrolled fires due to the accumulation of dead biomass. Nevertheless, rather than being perceived as a drawback, this can be seen as a potential source of materials. Carbonaceous materials are gaining increasing significance in the field of electrochemistry, normally improving their features through some type of thermal treatment. In this study, different types of thermal treatments applied to lignocellulosic wastes are reviewed pointing out pyrolysis and hydrothermal carbonization (HTC). Additionally, four environmental and energy electrochemical applications where this type of waste has been used as precursors of electrode materials are briefly examined: energy storage (supercapacitors, Li−Na‐ion batteries), hydrogen production (H2), microbial fuel cells (MFCs) and hydrogen peroxide (H2O2) production. Recent research findings, as discussed throughout this review, suggest a promising future for the utilization of lignocellulosic waste in electrochemical applications. [ABSTRACT FROM AUTHOR]

Published
2024
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35. DEVELOPMENT OF AUDIOVISUAL RESOURCES FOR PRACTICAL ACTIVITIES IN PILOT PLANT IN THE SUBJECT OF INTEGRATED PROCESS AND PRODUCT LABORATORY IN THE CHEMICAL ENGINEERING DEGREE

Author

Fernández-Marchante, Carmen María, primary, García-Vargas, Jesús Manuel, additional, Llanos, Javier, additional, de Lucas-Consuegra, Antonio, additional, Fernández Mena, Ismael, additional, Montiel, Miguel Ángel, additional, de la Osa, Ana Raquel, additional, Borreguero, Ana María, additional, Lacasa, Engracia, additional, Muñoz, Martín, additional, Sánchez-Silva, Maria Luz, additional, and García, María Teresa, additional

Published
2022
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44. Toward real applicability of electro-ozonizers: Paying attention to the gas phase using actual commercial PEM electrolyzers technology

Author

Rodriguez-Peña, Mayra, Barrios, Jose Antonio, Llanos, Javier, Saez, C., Barrera-Díaz, Carlos Eduardo, and Rodrigo, Manuel Andrés

Subjects
Technology, Environmental Engineering, Condiciones de operación, Health, Toxicology and Mutagenesis, Public Health, Environmental and Occupational Health, Temperature, Water, Operation conditions, General Medicine, General Chemistry, Electro-ozonizer, Pollution, Electrolyte formulation, Electro-ozonizador, Formulación de electrolitos, Ozone, CONDIAPURE®, Environmental Chemistry, Ozono, Water Pollutants, Chemical
Abstract

This work focuses on increasing the TRL of electro-ozonizer technology by evaluating the effect of electrolyte composition and operation conditions on the production of ozone, using an actual commercial cell, CONDIAPURE®, in conditions similar to what could be expected in a real application. Not only is attention paid to the changes in the concentration of ozone in the liquid phase, but also to those observed in the gas phase. The electrolyte and its recirculation flowrate, as well as operation temperatures and pressures are found to have significant influence on production rates. The most efficient way to produce ozone is operating at low temperatures and high pressures. In this work, 0.25 and 0.21 mg O3/min were obtained operating at 10 A in electrolytes consisting of aqueous solutions of perchloric and sulfuric acid, respectively, in tests carried out at 13 °C and 2 bars of gauge pressure. The negative effect of scavengers that appear electrochemically along the production of ozone is very important and seems to be partially compensated when organics are present in the solution due to the competition between the reaction of these scavengers with ozone or organics., Este trabajo se enfoca en incrementar el TRL de la tecnología de electro-ozonizadores mediante la evaluación del efecto de la composición del electrolito y las condiciones de operación en la producción de ozono, utilizando una celda comercial real, CONDIAPURE®, en condiciones similares a las que se podrían esperar en una aplicación real. No solo se presta atención a los cambios en la concentración de ozono en la fase líquida, sino también a los observados en la fase gaseosa. Se ha encontrado que el electrolito y su caudal de recirculación, así como las temperaturas y presiones de operación tienen una influencia significativa en las tasas de producción. La forma más eficiente de producir ozono es operando a bajas temperaturas y altas presiones. En este trabajo, 0.25 y 0.21 mg O 3/min operando a 10 A en electrolitos consistentes en soluciones acuosas de ácido perclórico y sulfúrico, respectivamente, en ensayos realizados a 13 °C y 2 bares de presión manométrica. El efecto negativo de los secuestrantes que aparecen electroquímicamente a lo largo de la producción de ozono es muy importante y parece ser parcialmente compensado cuando los orgánicos están presentes en la solución debido a la competencia entre la reacción de estos secuestrantes con el ozono o los orgánicos.

Published
2022

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