DESARROLLO DE CATALIZADORES Y ADSORBENTES CON APLICACIONES MEDIOAMBIENTALES A PARTIR DE UN RESIDUO PELIGROSO DEL RECICLAJE DEL ALUMINIO

PID2020-112656RB-C21

Nombre agencia financiadora Agencia Estatal de Investigación
Acrónimo agencia financiadora AEI
Programa Programa Estatal de I+D+i Orientada a los Retos de la Sociedad
Subprograma Programa Estatal de I+D+i Orientada a los Retos de la Sociedad
Convocatoria Proyectos I+D
Año convocatoria 2020
Unidad de gestión Plan Estatal de Investigación Científica y Técnica y de Innovación 2017-2020
Centro beneficiario UNIVERSIDAD PUBLICA DE NAVARRA
Identificador persistente http://dx.doi.org/10.13039/501100011033

Publicaciones

Found(s) 4 result(s)
Found(s) 1 page(s)

A comparative study of acid and alkaline aluminum extraction valorization procedure for aluminum saline slags

Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
  • Jiménez, Alejandro
  • Rives, Vicente
  • Vicente, Miguel Ángel
  • 0000-0001-9323-5981
A management process for saline slags, one of the wastes from Secondary Aluminum Production, is proposed. The process begins with a grinding step, followed by washing with water, which removed the fluxing salts but provoking the hydrolysis of AlN, yielding Al(OH)3 and ammonia. Sieving of the solid generated an intermediate and a fine fraction. The first one was rich in metallic aluminum, and can also be returned to the Secondary Aluminum Production. The fine fraction was submitted to a extraction process in acid (HCl or HNO3) or alkaline (NaOH, KOH or CsOH) conditions, under reflux at 90 ºC, obtaining an Al(III) solution that can be used in the synthesis of aluminum-based solids. HCl (1-8 mol/L) and NaOH (1-4 mol/L) were used as reference solutions, HNO3, NaOH and KOH were used under specific conditions; the slag fraction:extraction solution solid:liquid ratio was also varied. The optimum extraction conditions were: extraction time 2 h, solid:liquid ratio 3:10, concentration 3 mol/L for the NaOH medium and 4 mol/L for the HCl medium. More than 30% of the aluminum present in the fraction smaller than 0.4 mm was recovered (the remaining aluminum was present as insoluble phases, corundum and spinel). Acid or basic media can be selected depending on the final use of Al(III) solutions, the basic medium leading to an Al(III) solution with a lower amount of impurities. The hazardousness of the solid obtained after the extraction process was greatly decreased, making possible the use of this solid residue in sectors such as construction., This work was supported by 'Memoria de D. Samuel Solórzano Barruso' Foundation (FS/11-2020). AJ thanks Universidad de Salamanca and Banco Santander for a predoctoral contract. AG is grateful for financial support from the Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) through project PID2020-112656RB-C21. AG also thanks Santander Bank for funding via the Research Intensification Program.




Analysis by temperature-programmed reduction of the catalytic system Ni-Mo-Pd/Al2O3

Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
  • 0000-0003-0066-0052
  • Grande López, Lucía
  • Torrez Herrera, Jonathan Josué
  • 0000-0001-9086-4934
  • 0000-0001-9323-5981
Alumina-supported nickel catalysts are used to facilitate many reactions at various scales. However, the deactivation
of these catalysts is an important problem that has prompted the search for solutions such as the addition
of other metals that act as promoters. In this research, the interactions that form between the support and the
metals have been studied, a fundamental property that directly affects the performance of the catalyst. With this
idea, several Ni-Pd and Ni-Mo bimetallic and various Ni-Mo-Pd trimetallic samples have been prepared, and the
reduction capacity of the oxide phases by temperatura-programmed reduction has been analyzed and studied. It
has been found that in bimetallic catalysts, Pd favors the appearance of NiO species that are more easily reducible
than Mo. In the same way, the data obtained from the trimetallic simples suggest that the impregnation order of
Mo and Pd is not a determining factor in these catalysts. In addition, it has been found that the co-impregnation
of Ni with Pd gives better results than the sequential impregnation of these metals. The results obtained have also
shown that the order of nickel impregnation is decisive. In the case of Ni-Mo catalysts, by impregnating the
molybdenum first, catalysts with better reducing properties can be obtained., The authors are grateful for financial support from the Spanish
Ministry of Science and Innovation (AEI/MINECO) and the Government
of Navarra through projects PID2020-112656RB-C21 and PC034-035
BIOGASOLANA. Open access funding provided by Universidad Pública
de Navarra. JJTH thanks Universidad Pública de Navarra for a postdoctoral
grant. AG also thanks Santander Bank for funding via the
Research Intensification Program.




Synthesis strategies of alumina from aluminum saline slags

Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
  • Grande López, Lucía
  • Vicente, Miguel Ángel
  • 0000-0001-9086-4934
  • 0000-0001-9323-5981
Aluminum saline slags is a waste of the metallurgical industry that presents serious environmental problems
since it needs very extensive areas for its disposal, the toxicity it causes in the atmosphere and groundwater, in
addition to high transportation costs. The valorization of this residue by the synthesis of alumina, a compound
widely used in the chemical industry, generates a high impact and great interest. In this work, the strategies for
synthesizing alumina from aluminum saline slags are reviewed in a context of growing demand for this metal and
environmental crisis. The first sections present the aluminum production processes, both from natural bauxite
(primary process) and from the recycling of materials with a high aluminum content (secondary process); paying
attention to the waste generated and what environmental problems they produce. The main investigations that
have allowed to address the recovery of the waste generated are described below, focusing on the processes of
recovery/extraction of the aluminum present in its composition. The aluminum in these residues can be found as
a metal or forming other compounds such as simple or mixed oxides. Chemical processes are the most relevant,
especially those that deal with the acid and alkaline extraction of the metal. The most important section of the
work reports on the methods of synthesis of Al2O3, highlighting the methods of precipitation, sol-gel, hydrothermal synthesis, and combustion, among others. The work ends with a summary and conclusions section., Spanish Ministry of Science and Innovation (MCIN/AEI/10.13039/501100011033) through project PID2020-112656RB-C21. Open access funding provided by Universidad Pública de Navarra.




Metal-Al layered double hydroxides synthesized from aluminum slags as efficient CO2 adsorbents at pre- and post-combustion temperature

Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
  • 0000-0003-1248-341X
  • 0000-0001-9086-4934
  • 0000-0001-9323-5981
Layered double hydroxides (LDH) have been proposed as the materials that offer the best performance in the moderate-temperature range, between 200 and 450 °C, for CO2 adsorption, so the effect of some synthesis parameters and surface modification on their adsorption capacities is herein investigated. This work reports the use of M2+ (Co, Mg, Ni and Zn)/Al layered double hydroxides synthesized with a 3:1 molar ratio by the co-precipitation method and using aluminum extracted from saline slags as source of this metal as CO2 adsorbents. The synthesis and use of Zn/TiAl is also reported considering several proportions of Al-Ti. Structural characterization and comparison of the series has been achieved using powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), nitrogen physisorption at single bond196 °C and thermogravimetry measurements (TGA). The performance of calcined LDH as CO2 adsorbents was evaluated in the 50 – 400 °C temperature range and 80 kPa and results show that Ni6Al2 and Mg6Al2 samples present a significant adsorption capacity at low temperature (0.382 and 0.292 mmolCO2/g, respectively). At 400 °C only Mg6Al2 maintains its high adsorption capacity (0.275 mmolCO2/g) compared to the other calcined LDH. Its adsorption capacity at moderate-temperature range was proven to be better than that of a commercial Mg6Al2 sample. In all materials the CO2 adsorption capacity at 200–450 °C increased by incorporating potassium (K2CO3 and KOH as sources) up to 0.58 mmolCO2/g for Mg6Al2 +K2CO3. The addition of the amine TEPA in the low-temperature range worked for Co6Al2 and Mg6Al2 (increment > 40 %). In the case of Zn6Al2, the partial substitution of Al by Ti also increased the CO2 adsorption capacity from 0.177 to 0.244 mmolCO2/g, finding isosteric heats between 17.07 and 23.30 kJ/mol using the Clausius-Clapeyron equation., The authors are grateful for financial support from the Spanish
Ministry of Science and Innovation (MCIN/AEI/10.13039/
501100011033) through project PID2020-112656RB-C21. LS thanks the
Universidad Pública de Navarra for a post-doctoral Margarita Salas
grant, financed by the European Union-Next Generation EU.