Fractionation of Lignocellulosic Biomass by Selective Precipitation from Ionic Liquid Dissolution

Marta Lara-Serrano, Silvia Morales-delaRosa, Jose M. Campos-Martín, Jose L. G. Fierro
2019 Applied Sciences  
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
more » ... eved for 1:1 acetone:water. The fractionated lignocellulosic compounds were studied by using infrared spectroscopy, scanning electron microscopy and 1H 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 H2SO4) 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.
doi:10.3390/app9091862 fatcat:lrhca4zr2zh4vpfrooosilqaou