Fractionation of Lignocellulosic Biomass by Selective Precipitation from Ionic Liquid Dissolution

We propose the treatment of barley straw with 1-ethyl-3-methylimidazolium acetate [EMIMAcO] ionic liquids (ILs) and subsequent precipitation with antisolvent mixtures, thus allowing the separation of the sugar-rich fractions (cellulose and hemicellulose) from the lignin fraction. For this purpose, d...

Descripción completa

Detalles Bibliográficos
Autores: Lara-Serrano, Marta, Morales-delaRosa, Silvia, Campos Martín, José Miguel, García Fierro, José Luis
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/181552
Acceso en línea:http://hdl.handle.net/10261/181552
Access Level:acceso abierto
Palabra clave:Lignocellulosic biomass
Ionic liquid
Ethyl methyl imidazolium
Fractionation
Pretreatment
Barley straw
Descripción
Sumario:We propose the treatment of barley straw with 1-ethyl-3-methylimidazolium acetate [EMIMAcO] ionic liquids (ILs) and subsequent precipitation with antisolvent mixtures, thus allowing the separation of the sugar-rich fractions (cellulose and hemicellulose) from the lignin fraction. For this purpose, different concentration ranges of acetone:water antisolvent mixtures were studied. In all cases, a high recovery percentage and a high and effective separation of fractions was achieved for 1:1 acetone:water. The fractionated lignocellulosic compounds were studied by using infrared spectroscopy, scanning electron microscopy and <sup>1</sup>H nuclear magnetic resonance characterization techniques. This method allows the possibility of reusing IL, confirming the versatility of the established method. The fraction rich in cellulose and hemicellulose was subjected to acid hydrolysis (0.2 mol/L H<sub>2</sub>SO<sub>4</sub>) for 5 h at 140 °C, obtaining a yield of total reducing sugars of approximately 80%, much higher than those obtained in non-pretreated samples.