Efficient low-temperature lignocellulosic biomass pre-treatment to generate valuable and selective lignin and carbohydrate streams
This work package aims to tackle one of the main relevant bottlenecks for efficient biochemical biomass processing – an efficient lignocellulosic biomass deconstruction, more commonly known as biomass pre-treatment or fractionation.
Innovative, ground-breaking, and energy-efficient processes, operating at lower temperatures (up to 140°C) than state-of-the-art processes, will be developed to enable an integrated biomass upgrade concept and the development of new carbohydrate and lignin derivatives streams for bioenergy and added-value applications. These processes are based on non-hazardous catalysts and/or green solvents and aim to obtain a simultaneous reduction of the production of fermentation inhibitors and the need of hydrolytic enzymes for cellulose hydrolysis.
Two approaches will be developed:
- The use of catalytic amounts of ionic liquids (ILs) in aqueous solution to drive the direct conversion of hemicellulosic polysaccharides into sugars and to yield an easily digestible solid containing low crystallinity cellulose and upgradable lignin;
- The organosolv approach (using ketones, higher alcohols, imidazole, furans or other new alternative solvents alike) to selectively remove and depolymerize lignin to yield an easily digestible polysaccharide containing solid. The methods proposed will be benchmarked with state-of-the-art methods in terms of energetic efficiency and OPEX considering the saccharification yields and recovery of added-value lignin-derived products.
LNEG will conduct the studies with ILs and tests new acidic ILs to selectively fractionate biomass. Amongst others, methods involving imidazole to selectively remove and depolymerize lignin will also be explored. The purification of the sugar and lignin-derived streams will also be studied using CO2 extraction, resins and membrane-base processes. ENEA will focus its biomass pre-treatment studies on organosolv technology with higher alcohols and/or furans (two-phase system). Simultaneously, ECN shall optimise the organosolv fractionation processes using ketones and will develop novel biomass-derived products purification strategies using membranes. ECN will also employ their Cellulase Saver concept in the enzymatic digestion assays. In a cooperative work amongst all WP2 participants data from other more conventional biomass pre-treatment methods shall be gathered (e.g., hydrothermal, ethanol-water organosolv) for benchmarking with the more innovative technologies for biomass deconstruction.