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Chemical hydrolysis of hemicellulose from sugarcane bagasse. A comparison between the classical sulfuric acid method with the acidic ionic liquid 1-ethyl-3-methylimidazolium hydrogen sulfate

Rodrigues Marcoaurélio Almenara, da Costa Lopes André M., Lukasik Rafal M.

Acta Innovations

2023

no. 46

35--53

Dilute sulfuric acid and acidic ionic liquids are pretreatment methods used to selectively hydrolyze hemicellulose from lignocellulosic biomasses. In this work, a comparison between these techniques is carried out by treating sugarcane bagasse both with 1-ethyl-3-methylimidazolium hydrogen sulfate at different ionic-liquid and water contents and with H 2 SO 4 at the same conditions and equivalent ionic liquid molar contents. Results from the use of ionic liquid showed that it was possible to tune the biomass treatment either to achieve high hemicellulose hydrolysis yields of 72.5 mol% to very low furan and glucose co-production, or to obtain furfural at moderate yields of 18.7 mol% under conditions of low water concentration. In comparison to the use of ionic liquid, sulfuric acid pretreatment increased hemicellulose hydrolysis yields by 17%, but the 8.6 mol% furfural yield was also higher, and these yields were obtained at high water concentration conditions. Besides, no such tuning ability of the biomass treatment conditions can be made.

Acidic ionic liquids based on phosphonium chloride and metal chlorides – recyclable media and catalysts in the Diels-Alder reaction

Janus E.

Polish Journal of Chemical Technology

2010

Vol. 12, nr 2

33-37

Acidic ionic liquids based on trihexyltetradecylphosphonium chloride . P 6.6.6.14 Cl and six different metal chlorides (YCl 3 , YbCl 3 , MgCl 2 , ZnCl 2 , CuCl 2 , InCl 3 ) were prepared. The molar fraction of metal chloride (X MClx ) used for the formation of acidic ionic liquids with P 6.6.6.14 Cl was changed in the range from 0.3 to 0.5. The high catalytic activity in the Diels-Alder reaction of cyclopentadiene and various �ż,s-unsaturated carbonyl compounds showed ionic liquids at X MClx.0.4. In general, the highest product yields and endo:exo ratios were achieved in the acidic ionic liquids formed from MgCl 2 , YCl 3 and YbCl 3 . Thermogravimetric analysis suggested that the prepared ionic liquids were thermally stable up to nearly 400�‹C. Additionally, they could be reused with only little loss of catalytic activity after the 4th recycle.