Artículos (Ingeniería Química)

URI permanente para esta colecciónhttps://hdl.handle.net/11441/53665

Examinar

Mostrando 1 - 20 de 347

3D printed chitosan-pectin hydrogels: from rheological characterization to scaffold development and assessment
(Multidisciplinary Digital Publishing Institute (MDPI), 2021) Zarandona, Iratxe; Bengoechea Ruiz, Carlos; Álvarez-Castillo, Estefanía; Caba, Koro de la; Guerrero Conejo, Antonio Francisco; Guerrero, Pedro; Universidad de Sevilla. Departamento de Ingeniería Química
Chitosan-pectin hydrogels were prepared, and their rheological properties were assessed in order to select the best system to develop scaffolds by 3D printing. Hydrogels showed a weak gel behavior with shear thinning flow properties, caused by the physical interactions formed between both polysaccharides, as observed by FTIR analysis. Since systems with high concentration of pectin showed aggregations, the system composed of 2 wt% chitosan and 2 wt% pectin (CHI2PEC2) was selected for 3D printing. 3D printed scaffolds showed good shape accuracy, and SEM and XRD analyses revealed a homogeneous and amorphous structure. Moreover, scaffolds were stable and kept their shape and size after a cycle of compression sweeps. Their integrity was also maintained after immersion in PBS at 37◦C, showing a high swelling capacity, suitable for exudate absorption in wound healing applications.
A Circular Economy Approach in the Development of Superabsorbent Polymeric Matrices. Evaluation of the Mineral Retention
(MDPI, 2023-08) Álvarez-Castillo, Estefanía; Oliveira, Sonia; Bengoechea Ruiz, Carlos; Sousa, Isabel; Anabela Raymundo; Guerrero Conejo, Antonio Francisco; Universidad de Sevilla. Departamento de Ingeniería Química; Ministerio de Ciencia e Innovación (MICIN). España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Universidad de Sevilla. TEP229: Tecnología y Diseño de Productos Multicomponentes
This manuscript focuses on the production of polymeric matrices enriched in minerals and antioxidant compounds. The biopolymers employed are obtained from different by-products of the agro-food industry (porcine plasma protein, pea protein concentrate and soy protein isolate), which helps to revalorize them. Two different manufacturing techniques are employed to produce these matrices: 3D-printing and injection molding. Bioactivity was enhanced through immersion of the samples in magnesium glutamate and iron lactate solutions. To incorporate these minerals and bioactive compounds into the matrices, two additional stages are required: (1) an immersion stage in a mineral/bioactive containing solution, which allows simultaneous removal of the glycerol employed as plasticizer and entrapment of the minerals and bioactive compounds; and (2) a subsequent freeze-drying stage. Matrices produced through these manufacturing processes were assessed through water uptake capacity, mineral analysis, bioactivity and color measurements. The studied matrices have great potential in the food industry, as the threshold for claiming a significant mineral content was reached after the immersion stage. The presence of bioactive compounds could avoid the degradation of these matrices when food processing includes stages at relatively high temperatures.
A comparison of microfluidization and sonication to obtain lemongrass submicron emulsions. Effect of diutan gum concentration as stabilizer
(Elsevier, 2019) Santos García, Jenifer; Jiménez, Manuel; Calero Romero, Nuria; Undabeytia, Tomás; Muñoz García, José; Universidad de Sevilla. Departamento de Ingeniería Química; Ministerio de Economía y Competitividad (MINECO). España
The objective of this work was to develop emulsions containing lemongrass essential oil and Appyclean 6552 (emulsifier). The emulsions were prepared using two different processing techniques: microfluidization and sonication. A decrease in Sauter diameter with ultrasonic power and residence time in sonicator was observed, reaching values of 195 nm. Emulsions obtained by microfluidization presented similar Sauter values at lower pressures but they underwent recoalescence at higher pressures. However, the emulsion processed at the lowest homogenization pressure in microfluidizer showed the best stability. This emulsion was used as a reference to incorporate diutan gum, a thickener. The addition of diutan gum provoked the occurrence of viscoelastic properties, showing a weak gel-like behaviour in all the cases. A trend to cross-over point at lower frequencies was detected for 0.3 and 0.4 g/100 g diutan gum and this point was reached for 0.2 g/100 g diutan gum at 0.65 rad/s. This indicates a higher grade of structuration in more gum concentrated emulsions, leading to enhanced physical stability. Nevertheless, the emulsion formulated with diutan gum above 0.3 g/100 g showed coalescence just after preparation with the subsequent increase of droplet size (above 1 μm).
A Comparison of the Effect of Temperature on the Rheological Properties of Diutan and Rhamsan Gum Aqueous Solutions
(MDPI, 2019) García González, María del Carmen; Cely García, María del Socorro; Muñoz García, José; Alfaro Rodríguez, María del Carmen; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. TEP943: Reología Aplicada. Tecnología de Coloides
The rheological properties exhibited by gums make its use in applications interesting, such as foods, cosmetics, enhanced oil recovery, or constructions materials. Regardless of application field, the effect of temperature on these properties is of great importance, since these properties can be modified and cause the gum not to be useful for those conditions. Diutan and rhamsan gums are biopolymers, belonging to the sphingans, with similar structures which differ in the substituents of their side chains. It is known that both gums exhibit suitable viscoelastic properties and flow behavior when used as a stabilizer, gelling agent, or thickener. Both gums are widely used in food industry, personal care products, construction materials, oil operations, etc. For this reason, to know the effect of the temperature on their rheological properties is very helpful. For this purpose, small amplitude oscillatory shear measurements and flow curves, as a function of the temperature from 10 C to 60 C, have been performed, and the results obtained for both gums compared. The obtained results provide interesting information from an industrial point of view, since they reveal that the rheological properties remained almost unaltered in the temperature range assessed with diutan gum aqueous solutions, being slightly more viscous and viscoelastic than rhamsan gum solutions.
A Comprehensive Approach from Interfacial to Bulk Properties of Legume Protein-Stabilized Emulsions
(MDPI, 2019) Félix Ángel, Manuel; Romero García, Alberto; Carrera Sánchez, Cecilio; Guerrero Conejo, Antonio Francisco; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. TEP229: Tecnología y Diseño de Productos Multicomponentes
The correlation between interfacial properties and emulsion microstructure is a topic of special interest that has many industrial applications. This study deals with the comparison between the rheological properties of oil-water interfaces with adsorbed proteins from legumes (chickpea or faba bean) and the properties of the emulsions using them as the only emulsifier, both at microscopic (droplet size distribution) and macroscopic level (linear viscoelasticity). Two different pH values (2.5 and 7.5) were studied as a function of storage time. Interfaces were characterized by means of dilatational and interfacial shear rheology measurements. Subsequently, the microstructure of the final emulsions obtained was evaluated thorough droplet size distribution (DSD), light scattering and rheological measurements. Results obtained evidenced that pH value has a strong influence on interfacial properties and emulsion microstructure. The best interfacial results were obtained for the lower pH value using chickpea protein, which also corresponded to smaller droplet sizes, higher viscoelastic moduli, and higher emulsion stability. Thus, results put forward the relevance of the interfacial tension values, the adsorption kinetics, the viscoelastic properties of the interfacial film, and the electrostatic interactions among droplets, which depend on pH and the type of protein, on the microstructure, rheological properties, and stability of legume protein-stabilized emulsions.
A Concise Diastereoselective Total Synthesis of α-Ambrinol
(MDPI, 2023-03) López-Martínez, Josefa L.; Torres-García, Irene; Moreno-Gutiérrez, Irene; Oña Burgos, Pascual; Rosales Martínez, Antonio; Muñoz-Dorado, Manuel; Álvarez-Corral, Míriam; Rodríguez-García, Ignacio; Universidad de Sevilla. Departamento de Ingeniería Química; Horizon 2020-Research and Innovation Framework Programme of the European Commission - project 101022507 LAURELIN; University of Sevilla (Spain) Project 2020/00001014; University of Sevilla (Spain) Project 2021/00000422; Universidad de Sevilla. RNM932: Química e Ingeniería Sostenibles
(−)-cis-α-Ambrinol is a natural product present in ambergris, a substance of marine origin that has been highly valued by perfumers. In this paper, we present a new approach to its total synthesis. The starting material is commercially available α-ionone and the key step is an intramolecular Barbier-type cyclization induced by CpTiCl₂, an organometallic compound prepared in situ by a CpTiCl₃ reduction with Mn.
A Concise Route for the Synthesis of Tetracyclic Meroterpenoids: (±)-Aureol Preparation and Mechanistic Interpretation
(MDPI, 2020-08) Rosales Martínez, Antonio; Enríquez Giraudo, Lourdes; Jaraíz Maldonado, Martín; Pozo-Morales, Laura; Rodríguez-García, Ignacio; Díaz Ojeda, Emilio; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. RNM932: Química e Ingeniería Sostenibles
A new concise general methodology for the synthesis of different tetracyclic meroterpenoids is reported: (±)-aureol (1), the key intermediate of this general route. The synthesis of (±)-aureol (1) was achieved in seven steps (28% overall yield) from (±)-albicanol. The key steps of this route include a C–C bond-forming reaction between (±)-albicanal and a lithiated arene unit and a rearrangement involving 1,2-hydride and 1,2-methyl shifts promoted by BF3•Et2O as activator and water as initiator.
A High Productivity Bioprocess for Obtaining Metallic Copper from Printed Circuit Boards (PCBs)
(Elsevier, 2024) Iglesias González, María Nieves; Dorado, Antonio D.; Ramírez del Amo, Pablo; Mazuelos Rojas, Alfonso; Universidad de Sevilla. Departamento de Ingeniería Química; Ministerio de Ciencia e Innovación (MICIN). España
PCBs constitute a residue rich in metals, among which copper stands out due to its majority content, much higher than that found in natural deposits, so that it is a potential secondary resource. Many attempts have been made to recover copper via biohydrometallurgy because it is an environmentally friendly route, however, one of its main drawbacks is the low productivity achieved. A global process based on circularity for obtaining copper cathodes from PCBs is proposed. First, PCBs from end-of-life mobile phones are shred to sizes between 800 and 2000 µm. Copper is leached from these pieces in a continuous stirred tank reactor (CSTR) at high ferric concentration, at a moderate temperature of 60 °C reaching dissolution rate higher than 1 g/L·h and a yield of 99 %. The solution that leaves the CSTR with concentrations of up to 10 g/L of Cu is passed through a high-performance bioreactor for the regeneration of Fe(III). A biooxidation rate of 1.3 g/L⋅h was achieved, and no inhibition was observed. Concurrently, copper is recovered in metallic state by solvent extraction and electrowinning with recirculation streams becoming a more profitable and sustainable complete global process.
A kinetic comparison between laboratory and industrial scales in the copper blowing process
(2009) Martínez, José; Roselló Segado, Antonio; Carrillo de la Fuente, Francisco
A New Peracetylated Oleuropein Derivative Ameliorates Joint Inflammation and Destruction in a Murine Collagen-Induced Arthritis Model via Activation of the Nrf-2/Ho-1 Antioxidant Pathway and Suppression of MAPKs and NF-κB Activation
(MDPI, 2021-01) Castejón Martínez, María Luisa; Alarcón de la Lastra Romero, Catalina; Rosillo Ramírez, María de los Ángeles; Montoya García, Tatiana; Fernández-Bolaños Guzmán, José María; González Benjumea, Alejandro; Sánchez Hidalgo, Marina; Universidad de Sevilla. Departamento de Farmacología; Universidad de Sevilla. Departamento de Ingeniería Química; Ministerio de Economía y Competitividad (MINECO). España; Dirección General de Investigación (DGI). España; Junta de Andalucía; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER); Universidad de Sevilla; Universidad de Sevilla. CTS259: Farmacología Experimental y Farmacia Clínica; Universidad de Sevilla. FQM134: Química Fina de Carbohidratos
Oleuropein (OL), an olive tree secoiridoid and its peracetylated derivate (Per-OL) haveexhibited several beneficial effects on LPS-stimulated macrophages and murine experimental sys-temic lupus erythematosus (SLE). This study was designed to evaluate dietary Per-OL in comparisonwith OL supplementation effects on collagen-induced arthritis (CIA) murine model. Three-weeks-old DBA-1/J male mice were fed from weaning with a standard commercial diet or experimentalenriched-diets in 0.05 % (w/w) OL, 0.05% and 0.025% Per-OL. After six weeks of pre-treatment, arthri-tis was induced by bovine collagen type II by tail base injection (day 0) and on day 21, mice received abooster injection. Mice were sacrificed 42 days after the first immunization. Both Per-OL and OL dietssignificantly prevented histological damage and arthritic score development, although no statisticallysignificant differences were observed between both compounds. Also, serum collagen oligomericmatrix protein (COMP), metalloprotease (MMP)-3 and pro-inflammatory cytokines levels were ame-liorated in paws from secoiridoids fed animals. Mitogen-activated protein kinases (MAPK)s andnuclear transcription factor-kappa-B (NF-κB) activations were drastically down-regulated whereasnuclear factor E2-related factor 2 (Nrf2) and heme-oxygenase-1 (HO-1) protein expressions wereup-regulated in those mice fed with OL and Per-OL diets. We conclude that both Per-OL and itsparent compound, OL, supplements might provide a basis for developing a new dietary strategy forthe prevention of rheumatoid arthritis.
A new thiosalt depuration bioprocess for water- recycling in metallic sulphide mineral processing
(Elsevier, 2019-11) Mazuelos Rojas, Alfonso; Iglesias González, María Nieves; Montes Rosúa, Cristina; Lorenzo Tallafigo, Juan; Romero Aleta, Rafael; Carranza Mora, Francisco; Universidad de Sevilla. Departamento de Ingeniería Química
Economic and environmental imperatives force the metallic sulphide processing industry to re-use liquors that normally contain thiosalts; this processing entails difficulties in operation control and losses in metal-extraction performance. Bio-oxidation presents a promising option for thiosalt removal. Hitherto, this method has been tested to treat synthetic liquors containing only one thiosalt, either tetrathionate or thiosulphate, usually at low concentration (<1 g/L). In this article, bio-oxidation is studied of synthetic and real liquors containing mixtures of these thiosalts at concentrations close to 4.5 g/L. Coexistence of thiosulphate and tetrathionate in an acidic medium leads to strong and irreversible inhibition phenomena (performance losses close to 80%). In order to solve this problem, a previous treatment is proposed consisting of the 8-hour aeration of inlet solution after adding up to 20 mg/L and pH 1.5 of Cu2+ and sulphuric acid, respectively, resulting in the complete removal of thiosulphate and sulphite. Pre-treated real liquors were fed into a 1 L discontinuous stirred tank bioreactor and a 1 L continuous flooded packed-bed bioreactor, which were successfully started up and operated, thereby obtaining bio-oxidation rates close to the highest rates found in the literature with synthetic liquors.
A novel hydrometallurgical treatment for the recovery of copper, zinc, lead and silver from bulk concentrates
(Elsevier, 2021-03) Lorenzo Tallafigo, Juan; Romero Aleta, Rafael; Iglesias González, María Nieves; Mazuelos Rojas, Alfonso; Romero Aleta, Rafael; Carranza Mora, Francisco; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla
Nowadays sulphide ores exploitation is undergoing some troubles, which are hindering the treatment through traditional routes. Bulk flotation followed by a novel hydrometallurgical process can dodge these difficulties. In this work, an integral hydrometallurgical process consists of two ferric leaching steps, followed by a hot brine leaching stage, is proposed to recover target metals from a bulk sulphide concentrate (2.9% Cu, 7.4% Zn, 2.5% Pb, 67 ppm Ag and 37.2% Fe). In the first ferric leaching step, sphalerite, galena and copper secondary sulphides are dissolved and, in the second leaching step, a silver salt is added in order to catalyse chalcopyrite oxidation. If silver salt is added at the beginning of the process, sphalerite passivation is observed, and therefore zinc recovery is not possible. However, when catalytic leaching is performed after a previous ferric leaching, copper and zinc recoveries higher than 95% are achieved. The leached concentrate (0.3% Cu, 0.8% Zn, 3.3% Pb, 1438 ppm Ag, 38.0% Fe and 6.6% S0 ), is treated by a hot brine leaching. When hot brine leaching is performed at high pulp density, elemental sulphur removal is necessary to recover all silver added as a catalyst. Extractions higher than 95% for Zn, Cu and Pb are achieved as well as the total recovery of catalyst. The proposed process is silver surplus; therefore, this agent can be recirculated.
A novel Multi‐Phase Flash Sintering (MPFS) technique for 3D complex‐shaped ceramics
(Elsevier, 2022-03) Molina-Molina, Sandra; Gil González, Eva; Durán Olivencia, Francisco José; Valverde Millán, José Manuel; Perejón Pazo, Antonio; Sánchez Jiménez, Pedro Enrique; Pérez Maqueda, Luis Allan; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. Departamento de Electrónica y Electromagnetismo; Universidad de Sevilla. Departamento de Química Inorgánica; Spanish Government Agency Ministerio de Ciencia, Innovación y Universidades and FEDER project CTQ2017–83602-C2–1-R; Spanish Government Agency Ministerio de Ciencia, Innovación y Universidades and FEDER project CTQ2017–83602-C2–2-R; Junta de Andalucía-Consejería de Conocimiento, Investigación y Universidad and FEDER project P18-FR-1087; Junta de Andalucía-Consejería de Conocimiento, Investigación y Universidad and FEDER project US-1262507; Universidad de Sevilla. TEP-110 Reactividad de Sólidos; Universidad de Sevilla. FQM253: Electrohidrodinámica y Medios Granulares Cohesivos
This work demonstrates the first proof-of-concept of Multi-Phase Flash Sintering (MPFS). This novel tech- nique essentially consists of applying a rotating electric field to the sample by means of a multi-phase voltage source as furnace temperature increases. Several ceramic materials with different types of elec- trical conductivities are sintered within seconds at furnace temperatures much lower than those used for traditional DC flash sintering due to the higher power densities administered by a multi-phase power supply. Thus, ceramic materials are flashed at relatively lower applied voltages which minimizes un- desired phenomena such as localization and preferential current pathways. Furthermore, MPFS allows diverse electrode configurations to promote a more uniform electric field distribution, enhancing the sin- tering of 3D complex-shaped specimens. MPFS could be a true breakthrough in materials processing, as 3D complex-shaped specimens are homogeneously sintered at reduced temperatures, while keeping all the advantages of conventional flash sintering.
A Theoretical Study on the Inclusion of Fe, Cu, and Zn in Illite Clays
(Hindawi, 2019) Sánchez Coronilla, Antonio; Martín Fernández, Elisa Isabel; Fernández de Córdova Martín, Francisco José; Santos, Francisco Javier; Hidalgo Toledo, José; Universidad de Sevilla. Departamento de Química Física; Universidad de Sevilla. Departamento de Ingeniería Química
The inclusion of Fe, Cu, and Zn in (1, 0, 0), (0, 0.5, 0), and (0.5, 0.5, 0.5) sites of an illite with the KAl2Si4O12H2 structure has been studied. For the inclusion of the metals, their common oxidation states were chosen, that is, 0, +2, +3 and 0, +1, +2, for Fe and Cu, respectively, while 0 and +2 for Zn. Periodic DFT calculations were performed to know the most favourable site of incorporation of the ions. Energetically the most favourable site for the inclusion corresponds to the (1, 0, 0) coordinate for all the ions independently of their oxidation state. However, the highest oxidation state of the metals (Fe3+, Cu2+, and Zn2+) was the most favoured for being incorporated into the illite structure and was the selected ion for the discussion. In those structures, metal oxygen interaction plays an important role in stabilizing the systems. Structural and energetic results indicate that illite presents good adsorption characteristic of those Fe3+, Cu2+, and Zn2+ in the (1, 0, 0) site. Thus, those ions may be available for plants for its extraction by phytoextraction techniques and the consequent soil regeneration. The inclusion of a second metallic ion revealed the most favourable inclusion corresponding to the inclusion of Fe3+ ion. The inclusion of this ion modifies the coordination sphere around the first metal being available for subsequent extraction by phytoremediation or other techniques for clean-up of the soil and its regeneration.
Acid and enzymatic fractionation of olive stones for ethanol production using Pachysolen tannophilus
(Multidisciplinary Digital Publishing Institute (MDPI), 2020) Cuevas Aranda, Manuel; Saleh, Marwa; García-Martín, Juan Francisco; Sańchez, Sebastían; Universidad de Sevilla. Departamento de Ingeniería Química
Olive stones are an abundant lignocellulose material in the countries of the Mediterranean basin that could be transformed to bioethanol by biochemical pathways. In this work, olive stones were subjected to fractionation by means of a high-temperature dilute-acid pretreatment followed by enzymatic hydrolysis of the pretreated solids. The hydrolysates obtained in these steps were separately subjected to fermentation with the yeast Pachysolen tannophilus ATCC 32691. Response surface methodology with two independent variables (temperature and reaction time) was applied for optimizing D-xylose production from the raw material by dilute acid pretreatment with 0.01 M sulfuric acid. The highest D-xylose yield in the liquid fraction was obtained in the pretreatment at 201 C for 5.2 min. The inclusion of a detoxification step of the acid prehydrolysate, by vacuum distillation, allowed the fermentation of the sugars into ethanol and xylitol. The enzymatic hydrolysis of the pretreated solids was solely effective when using high enzyme loadings, thus leading to easily fermentable hydrolysates into ethanol. The mass macroscopic balances of the overall process illustrated that the amount of inoculum used in the fermentation of the acid prehydrolysates strongly aected the ethanol and xylitol yields.
Acidic and Heat Processing of Egg Yolk Dispersions
(MDPI, 2021-10) Aguilar García, José Manuel; Félix Ángel, Manuel; López González, Yolanda; Cordobés Carmona, Felipe; Guerrero Conejo, Antonio Francisco; Universidad de Sevilla. Departamento de Ingeniería Química; Universidad de Sevilla. TEP229: Tecnología y Diseño de Productos Multicomponentes
Egg yolk is a multifunctional ingredient widely used in many food products, wherein proteins are the dominant component contributing to this functionality. However, the potential risk of foodborne illness associated with egg use forces us to ensure that foodstuffs based on egg yolk are managed in a safe and sanitary manner. Lowering the pH under a certain value by adding acids could serve this purpose, but it can also greatly modify the rheological and functional properties of egg yolk. This research aims to assess the influence of citric acid on the rheological properties and microstructure of chicken egg yolk dispersions and their heat-set gels. The dispersions were prepared from fresh hen’s eggs yolks by adding water or citric acid to obtain a technical yolk (45 wt.% in solids) at the desired pH value. Viscoelastic measurements were carried out using a control stress rheometer, and microstructure was evaluated by cryo-scanning electronic microscopy (CryoSEM). An evolution of the viscoelastic properties of egg yolk dispersions from fluid to gel behavior was observed as the pH decreased until 2 but showing a predominantly fluid behavior at pH 3. The profile of viscoelastic properties along the thermal cycle applied is modified to a great extent, also showing a strong dependence on pH. Thus, the sol–gel transition can be modulated by the pH value.
Adaptation of an iron oxidising culture to extremely high Fe concentration by a programmed fed-batch bioreactor
(Elsevier, 2024-01) Perdigones, Blanca; Ramírez del Amo, Pablo; Mazuelos Rojas, Alfonso; Universidad de Sevilla. Departamento de Ingeniería Química; European Union’s Horizon 2020 research and innovation program under grant agreement N° 958252; Universidad de Sevilla. TEP186: Biohidrometalurgia
Ferric iron plays a key role as a leaching agent. In ferric leaching, the generated ferrous iron can be biologically regenerated by biooxidation. In commercial applications, microbial growth usually limits operational conditions such as iron concentration and pH. Therefore, design and operation are often conditioned by strict restrictions of pulp density and need of addition of alkaline reagents. In the present work a mixed culture consisting mainly of Acidithiobacillus ferrooxidans and Leptospirillum ferrooxidans has been adapted to extremely high iron concentrations in comparison with the reported information in literature. For this purpose, a programmed fed-batch bioreactor has been used. A continuous stirred tank reactor was operated for testing the adapted culture. As a result, no biological inhibition was observed with iron concentrations up to 50 g·L−1 and pH of 0.7. By this methodology, an adapted inoculum can be continuously generated in order to assist industrial operations.
Adjustment of olive fruit temperature before grinding for olive oil extraction. Experimental study and pilot plant trials
(Multidisciplinary Digital Publishing Institute (MDPI), 2021) Plasquy, Eddy; García Martos, José María; Florido Fernández, María del Carmen; Sola-Guirado, Rafael R.; García-Martín, Juan Francisco; Universidad de Sevilla. Departamento de Cristalografía, Mineralogía y Química Agrícola; Universidad de Sevilla. Departamento de Ingeniería Química
Harvesting at high temperatures and bulk transport can negatively influence the quality of olives and lead to undesirable alterations in the extracted oil. Cooling the fruit in the field would be the most logical solution, but it means that the olives arrive too cold at the mill for immediate processing. In this work, the use of warm water in the washing tub to warm up the fruit before grinding instead of flash heat treatment on the paste was assessed in two experiments. In the first one, at the laboratory level, the temperature after milling was determined in three olive cultivars, previously stored at 5 or 10 °C, and then submerged at different water temperatures (25, 30, and 35 °C) for 15, 30, 45, and 60 s. In the second one, two batches of olives were cooled in the field at 5 °C and then conditioned with washing water to obtain a paste at the entrance of the pilot plant malaxer at 27 °C. The temperature of the olives was measured at five points from the discharging up to their entering, as paste, into the malaxer. The results demonstrated the feasibility of the method as the temperature of the ground olives was kept at the desired temperature (28 ± 1 °C). The trials highlight the potential for automating an even more precise adjustment of the temperature of the olives before milling once the washing tub is equipped with a safe heating system.
Agro-Waste Sweet Pepper Extract-Magnetic Iron Oxide Nanoparticles for Antioxidant Enrichment and Sustainable Nanopackaging
(MDPI, 2024) López-Alcántara, EM.; Colindres-Vásquez, GM.; Fodil, Nouzha; Sánchez-Barahona, Marlon; Rivera-Flores, Octavio; Romero García, Alberto; Abdullah, Johar Amin Ahmed; Universidad de Sevilla. Departamento de Ingeniería Química; Ministerio de Ciencia e Innovación (MICIN). España; Agencia Estatal de Investigación. España; European Commission (EC). Fondo Europeo de Desarrollo Regional (FEDER)
This study synthesizes magnetic iron oxide nanoparticles from agro-waste sweet pepper extract, exploring their potential as antioxidant additives and in food preservation. Iron (III) chloride hexahydrate is the precursor, with sweet pepper extract as both a reducing and capping agent at pH 7.5. Characterization techniques, including microscopy and spectroscopy, analyze the sweet pepper extract-magnetic iron oxide nanoparticles. Antioxidant capacities against 2,2-diphenyl-1-picrylhydrazyl are assessed, incorporating nanoparticles into banana-based bioplastic for grape preservation. Microscopy reveals cubic and quasi-spherical structures, and spectroscopy confirms functional groups, including Fe–O bonds. X-ray diffraction identifies cubic and monoclinic magnetite with a monoclinic hematite presence. Sweet pepper extract exhibits 100% inhibitory activity in 20 min, while sweet pepper extract-magnetic iron oxide nanoparticles show an IC50 of 128.1 µg/mL. Furthermore, these nanoparticles, stabilized with banana-based bioplastic, effectively preserve grapes, resulting in a 27.4% lower weight loss rate after 144 h compared to the control group (34.6%). This pioneering study encourages institutional research into the natural antioxidant properties of agrowaste sweet pepper combined with magnetic iron and other metal oxide nanoparticles, offering sustainable solutions for nanopackaging and food preservation. Current research focuses on refining experimental parameters and investigating diverse applications for sweet pepper extract-magnetic iron oxide nanoparticles in varied contexts.
An alternative approach to recover lead, silver and gold from black gossan (polymetallic ore). Study of biological oxidation and lead recovery stages
(Elsevier, 2019-01) Lorenzo Tallafigo, Juan; Iglesias González, María Nieves; Mazuelos Rojas, Alfonso; Romero Aleta, Rafael; Carranza Mora, Francisco; Universidad de Sevilla. Departamento de Ingeniería Química
A novel procedure to recover lead, silver and gold from polymetallic sulphide ores, cleaner than the traditional hydrometallurgical route (hot brine leaching), is proposed. This process consists of a biooxidation stage, where sulphides are oxidised by the action of extremophiles, followed by an acid washing and a citrate leaching in which lead is recovered. The final solid obtained, mainly composed of quartz, is rich in silver and gold. This paper is focused on the biooxidation and the lead recovery of the black gossan, a polymetallic sulphide ore with valuable amounts of lead, silver and gold. Biooxidation performed with a mixed mesophilic culture (mainly Acidithiobacillus ferrooxidans) at 20% pulp density is able to dissolve the sulphide matrix, removing the gold refractory behaviour and producing jarosite, beaverite, gypsum and anglesite. A previous sulphuric acid washing of biooxidation residue greatly improves the lead recovery in the citrate stage. In the sulphuric acid washing, jarosite and beaverite are dissolved, being the most important variables the temperature and sulphuric acid concentration. The jarosite dissolution kinetics shows that the rate controlling step is the chemical reaction, with an activation energy of 86.4 kJ/mol. A linear relationship between the jarosite dissolved and lead recovered is found, reinforcing the necessity of a previous H2SO4 washing. The optimal pH range for lead recovery in the citrate solution is 5e9. Pulp densities higher than 5% produces an unstable solution, precipitating a part of the lead. A negative effect of gypsum has been confirmed through several citrate leaching tests performed with pure anglesite. The solid obtained after the studied stages is suitable to recover gold and silver that contains.

Examinar

Examinando Artículos (Ingeniería Química) por Título