Person: Rivas Siota, Sandra
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First Name
Sandra
Last Name
Rivas Siota
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
4 results
Search Results
Now showing 1 - 4 of 4
- Project number: 60
Item Elaboración de una metodología learn to program/program to learn para la enseñanza en el área de la Ingeniería Química empleando la herramienta matlab cody coursework para fomentar el e-learning(2019) Guijarro Gil, Maria Isabel; Domínguez Toribio, Juan Carlos; Yustos Cuesta, Pedro; Santos Mazorra, Victoria Eugenia; Oliet Pala, Mercedes; Toledo Gabriel, José Manuel; Alonso Rubio, María Virginia; Miranda Carreño, Ruben; Rodríguez Vega, Sergio; Rigual Hernández, Victoria de los Angeles; Villar Chavero, Maria del Mar; Lorenzo Fernández, David; Rivas Siota, SandraEl objetivo principal de este proyecto es la elaboración de una metodología learn to program/program to learn en el área de Ingeniería Química utilizando generadores de problemas y el sistema de corrección automática Matlab Cody Coursework. 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 Autohydrolysis and microwave ionic liquid pretreatment of Pinus radiata: Imaging visualization and analysis to understand enzymatic digestibility(Industrial Crops & 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; Rodriguez, 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 microscopy.Item Protic, Aprotic, and Choline-Derived Ionic Liquids: Toward Enhancing the Accessibility of Hardwood and Softwood(ACS Sustainable Chemistry & Engineering, 2020) Rigual Hernández, Victoria De Los Ángeles; Ovejero Pérez, Antonio; Rivas Siota, Sandra; Domínguez, Juan; Alonso Rubio, María Virginia; Oliet Pala, María Mercedes; Rodriguez, FranciscoA side-by-side comparison of softwood (pine) vs hardwood (eucalyptus) pretreatment using 3 protic, 3 aprotic, and 3 choline-derived ionic liquids (ILs) is proposed. While the protic ionic liquid 2-hydroxyethylammonium formate leads to alkali lignin dissolution at 30 °C after 1 h, the lack of interactions with the whole-cell wall limits the biomass disruption. On the contrary, the protic ionic liquid 1-methylimidazolium chloride produces a catalytic effect that extracts almost all of the hemicelluloses, and partially the lignin. Remarkable digestibilities are obtained with choline acetate ([Ch][OAc]) in eucalyptus (69%), while in pine, protic, and choline-derived ILs tested do not appear to be real “greener” alternatives to conventional ILs such as 1-ethyl-3- methylimidazolium acetate (the highest digestibility, 84%). Solid morphology revealed a smoother surface in pine pretreated with [Mim][Cl], and confocal fluorescence microscopy was used to distinguish surface holocellulose and lignin, highlighting differences in the accessibility of hardwood vs softwood due to the presence of surface lignin. Two-dimensional nuclear magnetic resonance spectroscopy of saccharified samples pretreated with [Ch][OAc] showed the presence of groups derived from acetate. Finally, thermogravimetric analysis and spectroscopy techniques reveal the difficulties in recovering the ionic liquid and conclude a work that describes the strengths and weaknesses of the ILs and biomasses studied.