A complete biomass fractionation strategy was employed, where all the three major biopolymers, namely cellulose, hemicellulose and lignin, are separated with higher efficiency and purity. Sequential treatment of hybrid poplar wood using autohydrolysis (160 °C, 60 min) and 1-ethyl-3-methylimidazolium acetate activation (60 °C, 3 h) resulted in significantly improved enzymatic saccharification and converted 88% of cellulose and 74% of hemicellulose into fermentable sugars. The superior saccharification rates of sequentially pretreated biomass was attributed to its altered crystalline state as well as reduced barrier properties.<br/><br/>The remaining solid fraction after enzymatic saccharification contained 94 % (w/w) lignin, which was equal to 74% yield based on the original biomass composition. The proposed two-step pretreatment process improved lignin yield by 77% and 23% when compared to the single-stage ionic liquid activation or autohydrolysis, respectively. Structural characterization by 2D-HSQC NMR and small-angle neutron scattering (SANS) revealed that the isolated lignin conserved 90% of the native inter-unit linkages, and exhibited unique reactive functionality towards ionic liquids, thereby highlighting the benefits of this process for lignin fractionation.

High quality lignin production through a sequential autohydrolysis & ionic liquid fractionation process

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.