Person: Alonso Rubio, María Virginia
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First Name
María Virginia
Last Name
Alonso Rubio
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
16 results
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Now showing 1 - 10 of 16
Item Technoeconomic Assessment of a Biomass Pretreatment + Ionic Liquid Recovery Process with Aprotic and Choline Derived Ionic Liquids(ACS Sustainable Chemistry & Engineering, 2021) Ovejero Pérez, Antonio; Ayuso Sebastián, Miguel Aythami; Rigual Hernández, Victoria De Los Ángeles; Domínguez Toribio, Juan Carlos; García González, Julián; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodríguez Somolinos, FranciscoIonic liquids have shown promising results in biomass pretreatment; however, an extensive water washing step is necessary. This fact increases not only the processing costs but also those associated with the ionic liquid recovery step. In this work, Eucalyptus globulus wood pretreated with two acetate-based ionic liquids, namely 1-ethyl-3-methylimidazolium acetate and choline acetate, has been washed with increasing volumes of water in order to analyze the influence of the amount of washing water used on the subsequent enzymatic hydrolysis stage and on the IL recovery costs. Vapor−liquid equilibria data of recovered ionic liquid/water mixtures have been determined to simulate the IL recovery step with Aspen Plus, calculating the operating costs using the Aspen Plus Economics Analyzer afterward. [Emim][OAc] was more efficiently washed and more effective toward wood pretreatment than [Ch][OAc]. Both IL/water systems were successfully modeled, and simulation studies showed that incremental volumes of water led to higher operating costs in the IL recovery step that are compensated with less IL makeup costs. Therefore, this work offers a technoeconomical analysis of the IL recovery step in a real biorefinery pretreatment process as a function of the volume of water used in the pretreated wood washing stage.Item Acidic depolymerization vs ionic liquid solubilization in lignin extraction from eucalyptus wood using the protic ionic liquid 1-methylimidazolium chloride(2020) Ovejero Pérez, Antonio; Rigual Hernández, Victoria De Los Ángeles; Domínguez Toribio, Juan Carlos; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodríguez Somolinos, FranciscoProtic ionic liquids have been proposed as effective solvents for the selective extraction of lignin from wood. In this work, the protic ionic liquid 1-methylimidazolium chloride has been used to extract lignin at different biomass loadings, temperatures, and times to understand the influence of treatment severity on the lignin dissolution mechanism. Themaximumlignin recovery (82.35 g lignin/100 g biomass lignin) was achieved at 10% (w/w) biomass loading, 135 °C, and 6 h. An increase in treatment severity leads to an acid cleavage of ether linkages, which increases the average molecular weight and thermal stability of lignins due to C-C repolymerization. HSQC-NMR analysis showed the effect of operating conditions on the predominant mechanismof lignin depolymerization. Atmild conditions, there is a preferential degradation of G units (the typical depolymerization mechanism of ionic liquid treatments); but at the most severe conditions, S units are predominantly removed, as usually occurs in acidic treatments. This work contributes to better understanding the different lignin extraction mechanisms occurring with a protic ionic liquid depending on different operating conditions.- Project number: PIMCD51/23-24
Item Aplicación de la metodología de aprendizaje basada en casos para la resolución de problemas de optimización multiobjetivo en Ingeniería de Procesos(2024) Rigual Hernández, Victoria De Los Ángeles; Alonso Rubio, María Virginia; Domínguez Toribio, Juan Carlos; García González, Julián; García Sanchez, Beatriz; Guijarro Gil, María Isabel; Mateo Fernández, Sara; Oliet Pala, María Mercedes; Ovejero Pérez, Antonio; Toledo Gabriel, José Manuel; Verdiá Barbará, Pedro; Yustos Cuesta, Pedro; Rigual Hernández, Victoria De Los ÁngelesEl objetivo principal que se propuso para este proyecto era acercar a los estudiantes de tercero del Grado de Ingeniería Química a las tareas propias de un Ingeniero Químico en un entorno laboral real, abordando problemas que impliquen la optimización simultánea de varias variables en un proceso químico. - Project number: 375
Item Elaboración de tutorías basadas en casos en la asignatura de Termodinámica Aplicada(2023) García González, Julián; Alonso Rubio, María Virginia; Ayuso Sebastián, Miguel Aythami; Domínguez Toribio, Juan Carlos; García Sánchez, Beatriz; García Somoza, Noelia; Guijarro Gil, María Isabel; Hopson Safatli, Cynthia Elizabeth; Mateo Fernández, Sara; Oliet Pala, María Mercedes; Ovejero Pérez, Antonio; Rigual Hernández, Victoria de los Angeles; Toledo Gabriel, José Manuel; Yustos Cuesta, Pedro Item MATLAB applications for teaching applied thermodynamics: thermodynamic cycles(Computer Applications in Engineering Education, 2023) Domínguez Toribio, Juan Carlos; Lorenzo Fernández, David; García González, Julián; Hopson Safatli, Cynthia Elizabeth; Rigual Hernández, Victoria De Los Ángeles; Alonso Rubio, María Virginia; Oliet Pala, María MercedesThe main objective of this study is to describe the teaching experience in an applied thermodynamics course, using MATLAB applications developed with MATLAB® App Designer. This course is compulsory for students in their sophomore year of the BSc in Chemical Engineering. MATLAB applications are developed to serve as tools for the teaching of thermodynamic cycles: steam and gas power, and vapor-compression refrigeration cycles. The computer applications are case-based problem generators, that is, based on chosen groups of initial variables, which values are randomly selected each time the MATLAB applications are run. Solutions of the cycle problems, which include thermodynamic cycles plotted in p–h, T–s, and p–v diagrams, and thermodynamic properties of each state of the cycle, are shown when students want to check their calculations. Moreover, the applications allow exporting initial data and solutions to an MS Excel file. The usability and learning experience of the applications were evaluated through anonymous surveys to students and the feedback of the academic staff involved in the course. The main problem, that the students referred, to was the utilization of the MATLAB applications that they considered it was not straightforward. The students believed that the utilization of these computer applications represented a significant improvement in teaching (70%) and expressed their interest in having similar materials in other degree courses (75%). After implementing the computer applications, the academic results showed an increase of ca. 16% in the pass rate.Item Thermal stability, degradation kinetics, and molecular weight of organosolv lignins from Pinus radiata(2018) Domínguez Toribio, Juan Carlos; Santos, Tamara; Rigual Hernández, Victoria De Los Ángeles; Oliet Pala, María Mercedes; Alonso Rubio, María Virginia; Rodriguez, FranciscoSeventeen organosolv lignin samples were obtained from the black liquor of an ethanol–water treatment using Pinus radiata as raw material under varied conditions applying an experimental matrix designed by employing response surface methodology (RSM). The thermal degradation of lignin samples was studied by a thermogravimetric analyzer (TGA) under an oxidative atmosphere. The thermal stability was estimated by the degradation temperature at 10% conversion (T10%), and the values of the kinetic parameters of the degradation process of lignins were determined using a 3-Gaussian distributed activation energy model (DAEM). The total distribution of the activation energy was obtained, and the mean activation energies of the Gaussian distributions were in agreement with the literature. In addition, the organosolv lignins were characterized by gel permeation chromatography (GPC) to determine their molecular weight distributions. Processing conditions affected the molecular weight of the extracted organosolv ethanol lignins and consequently influenced their thermal stabilities.Item Chitosan-reinforced cellulosic bionogels: Viscoelastic and antibacterial properties(2020) Villar-Chavero, Maria del Mar; Domínguez Toribio, Juan Carlos; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodriguez, FranciscoNew chitosan-reinforced cellulosic bionogels were successfully formulated with different chitosan loadings (0.25, 0.5, 0.75, and 1 wt/wt. %). These materials were developed using cholinium lysinate, a bio-ionic liquid, being an ecological alternative to conventional ionogels. The rheological properties of these materials showed. that all the studied viscoelastic properties were higher (elastic moduli, G'; loss moduli, G”; and complex viscosity, η*) as the chitosan loading increased. The reinforced bionogels were physical weak gels, and the proposed mechanism of formation was by hydrogen bonds. The bionogel with 1 wt/wt. % chitosan loading exhibited the highest viscoelastic properties (for 4 Hz, G': 552 kPa, G”: 99 kPa, and η*: 22 kPa·s). Regarding the antibacterial properties, these gels showed a good inhibitory capacity to S. aureus and E. coli, especially against the latter bacterium. For these reasons, these novel ecofriendly gels are promising in the pharmaceutical/medical and biosensors sectors to develop new functional materials.Item Evaluation of hardwood and softwood fractionation using autohydrolysis and ionic liquid microwave pretreatment(Biomass and Bioenergy, 2018) Rigual Hernández, Victoria De Los Ángeles; Santos, Tamara; Domínguez Toribio, Juan Carlos; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodríguez Somolinos, FranciscoLas diferencias entre la madera de frondosas y la de coníferas, dilucidan que su comportamiento frente a los pretratamientos varía. En este trabajo, se aplicaron pretratamientos de líquido iónico (LI) de microondas y autohidrólisis (AH) aEucalyptus globulus(como modelo de madera dura) yPinus radiata(como modelo de madera blanda). La comparación entre la madera dura y la madera blanda de líquido iónico microondas (IL) y la autohidrólisis (AH) se evaluaron en términos de composición química de los sólidos pretratados, líquido por corrientes composición (hemicelulosa y la extracción de lignina) y, sustratos digestibilidad enzimática. Además, las micrografías realizadas mediante microscopía electrónica de barrido (SEM) y microscopía de confocalfluorescencia corroboraron los resultados obtenidos. En este estudio, se ha demostrado que la eficacia del pretratamiento por autohidrólisis, a través de la maximización de la digestibilidad enzimática, es opuesta en la madera dura (73 g de glucano/100 g de glucano introducido en condiciones severas) y en la madera blanda (10 g/100 g de glucano). El pretratamiento con IL ha sido especialmente eficaz en la madera blanda, con digestibilidades más altas (78 g de glucano/100 g de glucano introducido) que las obtenidas en la madera dura (68 g de glucano/100 g de glucano introducido). Las imágenes de microscopía de confocalfluorescencia, junto con las imágenes SEM, han resultado ser una técnica clarificadora para explicar los resultados de la digestibilidad enzimática.Item Autohydrolysis and microwave ionic liquid pretreatment of Pinus radiata: Imaging visualization and analysis to understand enzymatic digestibility(Industrial Crops and Products, 2019) Rigual Hernández, Victoria De Los Ángeles; Domínguez Toribio, Juan Carlos; Santos, Tamara ; Rivas Siota, Sandra; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodríguez Somolinos, FranciscoSequential pretreatments provide advantages of every single process towards a complete biomass fractionation. In this work, autohydrolysis and IL microwave pretreatments are sequentialy studied, and their effect to enhance enzymatic hydrolysis is analyzed. Mild, intermediate and severe autohydrolysis are combined with four IL temperatures (50, 80, 120 and 150 °C). Pretreated solids are enzymatically hydrolyzed and compared in terms of chemical composition and morphology. Digital image analysis is employed to numerically determine the heterogeneity of the solids using surface fractal dimension and lacunarity parameters. In this study, the negative effect of intermediate and severe autohydrolysis, over the subsequent IL pretreatment is demonstrated. Mild autohydrolysis and high IL conditions (AH150IL120) results in digestibilities of 78.8 g of glucan/100 g of glucan introduced. High surface fractal values (in the range of 2.5461–2.7124) and low lacunarities (0.0818–0.2563) enhance the enzymatic accessibility of pine wood. Furthermore, the negative effect of softwood lignin accumulation in the surface is observed using confocal fluorescence microscopyItem Recovery and reuse of 1‑allyl-3-methylimidazolium chloride in the fractionation of pinus radiata wood(ACS Sustainable Chemistry and Engineering, 2017) Rigual Hernández, Victoria De Los Ángeles; Santos, Tamara ; Domínguez Toribio, Juan Carlos; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodríguez Somolinos, FranciscoSe espera que los líquidos iónicos sean disolventes potenciales para la biorrefinería. Sin embargo, su elevado coste ha limitadosu reciclado es esencial para el proceso. En este trabajo se estudia la capacidad de recuperar y reutilizar el líquido iónico cloruro de 1-alil-3-metilimidazolio ([Amim][Cl]) en el fraccionamiento de madera de Pinus radiata mediante calentamiento por microondas. En el proceso propuesto, se obtuvieron materiales ricos en celulosa y lignina. El líquido iónico utilizado se recuperó y reutilizó en los próximos ciclos hasta cinco veces. La caracterización del [Amim][Cl] recuperado demostró que, aunque la estructura del líquido iónico permanecía inalterada, se acumulaban algunas fracciones leñosas. Como consecuencia, se obtuvo una reducción de los rendimientos de fraccionamiento y se produjeron variaciones de la composición y amorfidad de las fracciones recuperadas. Mediante un balance de masas global, este estudio da una aproximación global de la concentración de los principales componentes y de las corrientes características que intervienen en los sucesivos ciclos.