Thermodynamic analysis, synthesis, characterization, and evaluation of 1-ethyl-3-methylimidazolium chloride: Study of its effect on pretreated rice husk

• Published in: Chinese journal of chemical engineering Vol. 60; no. 8; pp. 143 - 154
• Main Authors: Coronado-Aldana, Eileen Katherine, Ferreira-Salazar, Cindy Lizeth, Piñeros-Castro, Nubia Yineth, Vázquez-Medina, Rubén, Perdomo, Felipe A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2023; Universidad de Bogotá Jorge Tadeo Lozano,Facultad de Ciencias Naturales e Ingeniería,Cra.4 22-61,Cundinamarca,Bogotá,Colombia%Instituto Politecnico Nacional,CICATA Queretaro,Cerro Blanco 141,Colinas del Cimatario,76090 Queretaro,Mexico%School of Engineering,University of Edinburgh,Edinburgh EH9 3FB,United Kingdom
• Subjects: Fluid-phase equilibria; Ionic liquids; Thermodynamics; UNIFAC approach; Waste treatment; Ionic liquids; Thermodynamics; Fluid-phase equilibria; UNIFAC approach; Waste treatment
• ISSN: 1004-9541; 2210-321X
• DOI: 10.1016/j.cjche.2023.02.023

[Display omitted] •Synthesis of ionic liquid (IL) is modeled and experimentally validated.•The model of IL yields the theoretically optimal conditions to perform the reaction.•Thermodynamics, reactivity, and pretreating ability of IL on rice husk are evaluated.•Modified UNIFAC approach predicts solid–liquid phase coexistence for reacting system.•Synthesized IL is affordable and has good ability to dissolve rice husk cellulose. This work is focused on the determination of the optimal reaction conditions to synthesize the ionic liquid 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]) and assess its suitability for the pretreatment of rice husk. The modified UNIFAC (UNIversal quasi-chemical Functional-group Activity Coefficients) approach for ionic liquids is used to develop a thermodynamic model that describes the reactive system methylimidazole (MIM), chloroethane (C2H5Cl) and [EMIM][Cl]. The model allows to study the phase equilibria coexistence (vapor–liquid equilibria and solid–liquid equilibria) and yields the theoretically optimal conditions to synthesize the ionic liquid. The model predictions are validated with the available experimental and reported data. By implementing the developed model, a simple way to synthesize ionic liquid [EMIM][Cl] was found allowing to study its influence on the structure and morphology of pretreated rice husk. The lignocellulosic materials involved in this study are characterized by their composition, enzymatic digestibility, scanning electron microscopy, and crystallinity. Compared to untreated material, [EMIM][Cl]-pretreated rice husk produces cellulose that can be efficiently enzymatic hydrolyzed with high sugar yields. This work offers a suitable methodology to include the synthesis and thermodynamics of the solvent media within the design of low-cost ionic liquids for lignocellulosic biomass pretreatment.