Table 4 Pretreatment conditions, efficiency, and results of different organic acid pretreatment systems
From: Organosolv pretreatment: an in-depth purview of mechanics of the system
Organic acids | Biomass | Pretreatment conditions | Pretreatment result | References | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
Solvent concentration | Solid–liquid ratio | Temperature (°C) | Reaction time (min) | Cellulose content | Hemicellulose content | Lignin content | Others | |||
Acetic acid–formic acid | Wheat straw | 65/35 mass ratio, 85% in water | 0.96:10 | 105 | 180 | 63% and 93% of cellulose purity and recovery | 58% wheat straw xylan | 78% and 84% lignin purity and recovery | 44% proteins, 69% minerals, etc | (Snelders et al. 2014) |
Formic acid | Sugarcane tops | 85% | 1:7.5 | 125 | 90 | 84.7% cellulose retention | ~ 96.3% hemicellulose removal | ~ 90.8% lignin removal | – | (Pathak et al. 2021) |
Bamboo | 85% | 1:7 | 145 | 45 | 42.2% cellulose pulp | 8.5% hemicellulose-rich fraction | 31.5% lignin-rich fraction | 3.56% furfural and 3.80% acetic acid | (Zhang et al. 2018) | |
Oxalic acid | Corn cob | – | 1:20 | 140 | 150 | – | 85.0% yield of xylose | – | 178.93–69.76 mg/g total sugar content | (Cheng et al. 2018) |
Yellow poplar | 82 mM | 1:8 | 160 | 58 | 64.09% glucan | – | 25.16% lignin composition | High ethanol yield 34.54 g/L | (Jeong and Lee 2016) | |
Cassava stem | 1% w/v | 1:10 | 121 | 15 | – | – | – | 1.509 g/L Total reducing sugar | (Sivamani and Baskar 2018) | |
Maple wood | 0.5% |  | 160 | 27.5 | 1.7% glucose yield | 87.5% total xylose yield | – | – | (Zhang et al. 2013) | |
Acetic acid | Forest residues | 50% v/v | 1:10 | 190 | 60 | 31.2–40.3% cellulose | 16.2% hemicellulose | – | 12.2–46.7–52.5% total carbohydrates | (Kabir et al. 2015) |