Centro UTN QUIMOBI - Difusión Científica - Artículos de Revista

Permanent URI for this collectionhttp://48.217.138.120/handle/20.500.12272/674

Browse

Author: search.filters.author.Dagnino, Eliana PaolaSubject: search.filters.subject.soda-ethanol-water process

Search Results

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Optimization of the soda-ethanol delignification stage for a rice husk biorefinery
    (2017-03-01) Dagnino, Eliana Paola; Felissia, Fernando E.; Chamorro, Ester Ramona; Area, María Cristina
    The aim of this work was to optimize the delignification of the hemicelluloses-free fraction of rice husk to obtain fractions of lignin, cellulose, and inorganics, which could be valorized in the context of the rice husk biorefinery. The hemicelluloses were pre-extracted from the raw material by dilute sulfuric acid, and a soda-ethanol-water process was used for delignification. Two experimental designs were carried out to evaluate different ranges of the same variables (strong and light conditions), aiming to promote maximal delignification or delignify while protecting carbohydrates. The optimal delignification points were obtained using 13 and 8% of NaOH (%w/w on solid material), in a 50:50 and 54:46 ethanol:water solution. In these conditions, 94.3 and 90.1% of lignin and almost 100 and 40% of inorganics were removed from the solid, respectively. The used soda-ethanol-water process can be defined as a soda process additivated with ethanol, showing significant advantages over soda-anthraquinone process for the fractionation of lignocellulosic materials.
  • Thumbnail Image
    Item
    Studies on lignin extraction from rice husk by a soda-ethanol treatment : kinetics, separation, and characterization of products
    (2018-01-01) Dagnino, Eliana Paola; Chamorro, Ester Ramona; Felissia, Fernando E.; Area, María Cristina
    The delignification kinetics of lignocellulosic waste is an important tool for the study of the technical-economic viability of biorefinery processes. The aim of this work was to study the kinetic of lignin extraction by a soda-ethanol treatment of hemicelluloses-free rice husk, within the framework of a biorefinery. Additionally, the type of phenolic structures in the extracted lignin and the behavior of inorganics were evaluated. The kinetic study was carried out at 140, 150, and 160 °C, at different times between 3 and 100 min of reaction for each temperature. A first order kinetic model was adjusted to the experimental data of residual lignin in the treated solid in the fast and slow phase. The kinetic constant k0 varied from 0.021 to 0.035 min−1 for 140–160 °C. The activation energies were 38.59 kJ/mol and 33.47 kJ/mol for the fast and slow phase, respectively. The inorganics components remained in the solid and the proportion of silicon increased through all treatments. About 50% of the initial lignin with 1% of inorganics was recovered by precipitation. The percentage of total OH in lignin remained high, about 8.5%, and decreased with the temperature but not with the time of the reaction.