Table 1.

The advantages and disadvantages of traditional pretreatment methods.

Pretreatment methods	Advantages	Disadvantages	References
Biological method	Mild treatment conditions, high efficiency of enzymatic hydrolysis	Long processing time	Chen et al., 2017b
Physical method	Increase the reaction area	Lignin cannot be removed	Aguilar-Reynosa et al., 2017
Combination method	Improve response efficiency, reduce energy consumption	Complicated operation, immature technology	Teymouri et al., 2005
Acid pretreatment	Degradation of large quantities of hemicellulose	Corrosion of the equipment, pollution of the environment	Rezania et al., 2020
Alkaline pretreatment	Degradation of large amounts of lignin	Long pretreatment time	Cheah et al., 2020
Common organic solvents	Removing large amounts of lignin and hemicellulose	High toxicity, pollution of the environment	Zhang et al., 2016c
ILs	High thermal stability, low vapor pressure	High cost, high toxicity	Khan et al., 2021
DES	High thermal stability, low cost, low toxicity	High viscosity, not easy to recycle	Satlewal et al., 2018