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

Biorefineries integrate processes for the sustainable conversion of biomass into chemicals, materials, and bioenergy so that resources are optimized and effluents are minimized. Despite the vast potential of lignocellulosic biorefineries, their success depends heavily on effective, economically viable, and sustainable biomass fractionation. Although efficient, organosolv pretreatment still faces challenges that must be overcome for its widespread utilization, mainly related to solvent type and recycling, robustness regarding biomass type and integration of hemicellulose recovery and use. This review shows the recent advances and state-of-the-art of organosolv pretreatment, discussing the advances, such as the use of biobased solvents, whilst also shedding light on the perspectives of using the streams - cellulose, hemicellulose, and lignin - to produce biofuels and products of high added value. In addition, it presents an overview of the existing industrial implementations of organosolv processes and, lastly, shows the main scientific and industrial challenges and opportunities for this process.