Novel pretreatment pathways for dissolution of lignocellulosic biomass based on ionic liquid and low temperature alkaline treatment. (October 2016)

• Record Type: Journal Article
• Authors: Heggset, Ellinor B.; Syverud, Kristin; Øyaas, Karin
• Is Part Of: Biomass and bioenergy. Volume 93(2016:Oct.)
• Page Start: 194
• Page End: 200
• Publication Date: 2016-10
• Subjects: Biomass -- Pretreatment -- Ionic liquid -- Alkali -- Urea -- Low temperature; Biomass energy -- Periodicals; Biomass -- Periodicals; Energy-Generating Resources -- Periodicals; Bioénergie -- Périodiques; 333.9539
• DOI: 10.1016/j.biombioe.2016.07.023
• Languages: English
• ISSNs: 0961-9534

Abstract

Abstract: Pretreatment, fractionation and hydrolysis remains costly and challenging process steps in biochemical conversion of softwoods. Here, ionic liquid pretreatment using 1-ethyl-3-methylimidazolium acetate (EMIM-OAc) at high temperature (100 °C, 6 h) and alkali based (NaOH/urea) pretreatment at sub-zero temperature (−18 °C, 24 h) were compared and combined in studies of Norway Spruce biomass deconstruction. Both treatments significantly improved the enzymatic digestibility of the biomass. EMIM-OAc gave higher glucan than mannan digestibility, indicating a more pronounced effect on the cellulose polymer than on the hemicellulose polymer. In contrast, low temperature alkali pretreatment using NaOH or NaOH + urea gave a more pronounced effect on mannan than on glucan digestibility. By combining the two methods the total monosugar yield after enzymatic hydrolysis was improved by 20–50% as compared to using ionic liquid or alkali based pretreatment alone. Lignin dissolution was low for both methods under the conditions studied. Highlights: Softwood pretreatment and saccharification to fermentable sugars. EMIM-OAc ionic liquid processing. Sub-zero alkaline processing (−18 °C). Combined ionic liquid and alkaline processing.