Fundamental review of organosolv pretreatment and its challenges in emerging consolidated bioprocessing

摘要

Lignocellulosic biomass is the most abundant renewable source of bioenergy. However, its intertwined structures prevent the embedded cellulose and hemicellulose from undergoing further chemical transformations. Organosolv pretreatment has been known to be effective in reducing the recalcitrance of lignocellulosic biomass. It possesses advantages in the recovery of components and the recovered components such as cellulose can be converted into bioproducts through consolidated bioprocessing (CBP). The main objective of this paper is to review recent developments in organosolv pretreatment, including a comparison of different organic solvents and their optimum operation conditions in terms of pretreatment performance and efficiency. Conventional solvents were also compared with several emerging solvents to discover more potential utilization of organosolv pretreatment. This paper also reviewed fundamental knowledge regarding organosolv pretreatment such as its mechanism, and the chemical and physical properties of the solvents, which are still rarely discussed in the literature due to a lack of conclusive information. The challenges and way forward for organosolv pretreatment were also analyzed in depth to consider the synergistic advantages after the integration of organosolv pretreatment into CBP. It is believed that, through more fundamental exploration and optimization work, organosolv pretreatment can play a vital role in determining the sustainability of CBP, to pave the way for more efficient bioprocessing in the future. (c) 2020 Society of Chemical Industry and John Wiley & Sons, Ltd