Extraction of lignin from lignocellulose at atmospheric pressure using alkylbenzenesulfonate ionic liquid

Abstract

Lignocellulosic materials are a potentially valuable source of both aromatic compounds via the lignin component and sugars from the cellulose and hemicellulose components. However, efficient means of separating and depolymerising the components are required. An ionic liquid mixture containing the 1-ethyl-3-methylimidazolium cation and a mixture of alkylbenzenesulfonates with xylenesulfonate as the main anion was used to extract lignin from sugarcane plant waste at atmospheric pressure and elevated temperatures (170-190 • C). The lignin was recovered from the ionic liquid by precipitation, allowing the ionic liquid to be recycled. An extraction yield exceeding 93% was attained. The lignin produced had a molecular weight of 2220 g/mol after acetylation. The regenerated ionic liquid showed good retention of structure and properties. The other product of the extraction was a cellulose pulp, which can be used in further processing.

Ionic liquid-tolerant microorganisms and microbial communities for lignocellulose conversion to bioproducts

“…Used as a pretreatment regime, ILs have been demonstrated to be effective on a variety of biomass sources, such as switchgrass, corn stalk, rice straw, bagasse, sugarcane, pine wood, maple wood, hardwood red oak, and mixtures of softwoods (Fort et al 2007;Kilpelainen et al 2007;Lee et al 2009;Li et al 2010;Li et al 2008;Singh et al 2009;Sun et al 2009;Tan et al 2009;Trinh et al 2015). They are also becoming more cost-effective as compared to other pretreatment options (George et al 2015).…”

Microwave-assisted extraction of lignin from triticale straw: Optimization and microwave effects

“…It has more rarely been applied to the specific extraction of lignin, either as a pretreatment technique prior to enzymatic mild acidolysis (Zoia et al, 2008)o ri n combination with ionic liquids (Tan et al, 2009;Sun et al, 2009;Fu et al, 2010). The first application allowed improving the lignin purity but was devoted to the pretreatment step rather than the extraction one.…”

Spotlight on ionic liquids

“…The realization that task-specific ILs can be created via simple and systematic chemical modifications of the constituent ions takes these systems beyond the promise of designer solvents to highly useful systems for diverse applications including drug delivery and as active pharmaceutical ingredients, [1][2][3] solvents for green processing of otherwise insoluble biomolecules such as cellulose, 4,5 highly energetic materials, 1 and novel electrolytes for energy applications such as batteries, fuel cells, and solar photoelectrochemical cells. [6][7][8][9] Plechkova and Seddon 10 estimated that there may be in excess of 10 6 possible ILs if all currently known IL cations and anions were to be paired, and as many as 10 18 if all ternary systems were to be investigated.…”