(503a) Fractionation of Lignocellulose and Tandem Preservation of Lignin and Carbohydrates Using Aldehyde Sulfonic Acid

The effective fractionation of lignocellulose with low energy inputs while preserving the obtained cellulose, hemicellulose, and lignin is the key to utilize lignocellulose economically and effectively. This study presents an aldehyde sulfonic acid enabled mild-condition (e.g., 60 °C for 2 h or 80 °C for 15 min) process that can near-completely fractionate hardwood chips into water-soluble lignin, xylose-derived dioxolo, and cellulose. The bifunctional aldehyde sulfonic acid can depolymerize hemicellulose and lignin by the sulfonic acid group and tandemly react and preserve the obtained xylose and the depolymerized lignin through the aldehyde group autocatalyzed by the sulfonic acid group. The obtained lignin is enriched with beta-O-4 linkage, and is not condensed, and is water-soluble. The water-soluble lignin can be separated as cleavable (cyclic acetal-linked) surfactant through membrane dialysis. Xylose can be effectively recovered from xylose-derived dioxolo through acidolysis. The obtained cellulose can be directly hydrolyzed to glucose using cellulolytic enzymes. The unreacted aldehyde sulfonic acid can be recycled for reuse.