Fractionation of banana rachis using ionic liquids: Sustainability and selectivity of choline lactate

Lignocellulosic biomass is a valuable source of energy and raw materials. However, in order to unlock the full potential of this renewable source, it needs to be fractionated to separate its main components: cellulose, lignin and hemicellulose. Current extraction methods (Kraft, Organosolv) are very effective but are not entirely free of drawbacks, such as a high energy and water consumption and the use of potentially toxic chemicals. Ionic liquids (ILs) have been explored as a sustainable alternative for biomass treatment since they have shown selectivity during biomass fractionation. In this work, the ability of 6 ILs to selectively extract lignin from banana rachis was investigated, including choline lactate [Cho+][Lac-] which is acknowledged by its lack of toxicity, biodegradability and ease of synthesis from renewable resources. Recovered cellulose batches were characterised by X-ray diffraction and FT-IR spectroscopy and compared with cellulose from banana rachis obtained by traditional alkaline pulping process.