Effective Lignin-First Fractionation of Softwood Lignocellulose Using a Mild Dimethyl Carbonate Organosolv Process
2019-11-25T16:30:09Z (GMT)
by
Large-scale
biorefineries converting lignocellulosic biomass into chemicals, fuels, and
energy require a cost-effective pretreatment process that can effectively
fractionate all main lignocellulose constituents. A mild organosolv process has
been developed using a system of dimethyl carbonate (DMC) and ethylene glycol
(EG) as solvent. Softwood biomass (pine, spruce, cedar, and Douglas fir) was
fractionated using mild conditions: 140 °C, 40 min, DMC-EG, and sulfuric acid.
Organosolv pulping of the softwood biomass usually leads to poor
delignification hampering enzymatic cellulose hydrolysis. However, for the
developed system, effective pretreatment and subsequent enzymatic cellulose
hydrolysis into glucose (up to 84.7%) was observed in combination with a high
yield of monomeric hemicellulose sugars and monophenolic compounds from lignin
(up to 98% compared to theoretical monomer yield). In sum, effective
fractionation and in situ lignin depolymerization was demonstrated for various
softwood feedstock combined with limited solvent loss at mild conditions and
low reactor pressure.
License
CC BY-NC-ND 4.0