Biorefinery approach for lignocellulosic biomass valorisation with an acidic ionic liquid

Abstract

An acidic ionic liquid offers an exciting window to directly produce hemicellulose pentoses and to valorise cellulose and lignin.

The Effect of Chemical Character of Ionic Liquids on Biomass Pre-Treatment and Posterior Enzymatic Hydrolysis

“…The same IL was also reported as able to hydrolyse and to convert hemicellulose fraction of wheat straw with no additional catalyst used [17]. The pre-treatment with this IL produced a liquor rich in hemicellulosic sugars, furans and organic acids, and a solid fraction constituted mainly of cellulose and lignin.…”

“…Alternative approach of the biomass processing with IL is the employment of ILs as both solvent and catalyst. In these processes, ILs hydrolyse mainly polysaccharide fraction without the presence of other catalyst [5,16,17]. Therefore, ILs with acidic character demonstrated ability to selectively hydrolyse hemicellulose [18,19], both cellulose and hemicellulose [20], or lignin [21].…”

“…One of the most commonly used IL in such approaches are those based on hydrogen sulfate ([HSO4]). They are able to catalyse a selective hemicellulose hydrolysis [17][18][19]. Furthermore,…”

“…Learnt on previous works about processing of biomass with hydrogen-bond basic ([emim][OAc]) [11] and hydrogen-bond acidic ([emim][HSO4]) [17,19] ILs, this work aims to demonstrate the importance of biomass type on the efficiency of the biomass pre-treatment as well as on the efficiency of subsequent enzymatic hydrolysis. This was examined using two very distinct types of biomasses, namely herbaceous (wheat straw) and hardwood such as Eucalyptus globulus and allowed elucidating change observed in a chemical structure of the biomass, cellulose crystallinity and consequently their effects on the cellulose-rich pulp hydrolysability.…”

A Single Step Fractionation of Lignocellulose in Aqueous Solutions of a Carboxylic Acid‐Functionalized Ionic Liquid

“…It was reported that up to 85% of the lignin and up to 100% of the hemicellulose were solubilized into the IL solution, and the hemicellulose dissolved mainly in monomeric form, and pentoses were partially converted into furfural. Up to 77% of the glucose contained in the biomass could be released by enzymatic saccharification of the pulp ,…”