Organosolv pretreatment for biorefineries: Current status, perspectives, and challenges

Formation of lignin alkyl-O-alkyl ether structures via 1,6-addition of aliphatic alcohols to β-O-4-aryl ether quinone methides

“…The alcohol organosolv process is a promising lignin-first-type method because of its inherent advantages, such as low solvent cost, low toxicity, coproduction of a highly pure lignin fraction, great significance for enzymatic hydrolysis of cellulose, easy recovery, and reuse of solvent. 73 It is also a method for obtaining lignin suitable for selective depolymerization and modification, which may offer better strategies for lignin valorization. Methanol and ethanol, as low boiling point alcohols, particularly have attracted strong research interest for organosolv pretreatment due to their promising solvent capabilities.…”

Beyond Yield Optimization: The Impact of Organosolv Process Parameters on Lignin Structure

“…[31,32] In recent decades, the focus has been on environmentally friendly biorefinery processes for the full utilization of renewable raw materials and the extraction of lignin with high added value, which is precisely the approach of the organosolv process. [5] Most organic solvents used in the organosolv process are either polar protic or polar aprotic solvents. This results in a cellulose-rich fraction, an organolignin fraction, and a watersoluble fraction containing hemicellulose, acid-soluble lignin, carbohydrate degradation products, organic acids, and other components.…”

“…Aqueous ethanol concentrations of approximately 30-80 %wt are used for this process. [5,35,36] To gain a better chemical understanding of the organosolv process, it is necessary to identify the mechanisms of the main reactions taking place in the system. These lead to the degradation of lignin and hemicellulose into lower molecular weight components that are soluble in the used solvent mixture.…”

“…One promising approach is the organosolv process, in which lignin and hemicellulose are extracted at elevated temperatures using a mixture of an organic solvent and water. [ 5 ] The advantages of this process are the gentle recovery of a very pure lignin fraction and easy recovery of the solvent. In addition, they have great significance for cellulose biorefinery.…”

Recent advances in hydrotropic solvent systems for lignocellulosic biomass utilization

“…[7][8][9] Biomass processing solvents including organic solvents, aqueous phase hydrotropes, and ionic liquids have been investigated to understand their effectiveness and fundamental mechanisms for biomass fractionation. [10][11][12][13][14][15][16][17][18][19][20][21] In addition to the technical performance of these solvents, their economic feasibility and environmental sustainability have been evaluated and considered in recent studies. 22,23 Despite many efforts in studying these solvent systems, many technical barriers remained to be overcome for commercialization.…”