From: Organosolv pretreatment: an in-depth purview of mechanics of the system
Alcohols | Biomass | Pretreatment condition | Result | References | ||||
---|---|---|---|---|---|---|---|---|
Solvent concentration | Solid–liquid ratio | Temperature (°C) | Reaction time (min) | Catalyst/additional conditions | ||||
Ethanol | Softwood | 63 wt% | – | ~ 235 | 90 | Formic acid | ~ 65% delignification | (Agnihotri et al. 2015) |
Sugarcane bagasse | 50 wt% | – | ~ 210 | 90–120 | ~ 80% delignification | |||
Hybrid poplar | 60% | 8:1 ratio | 160–180 | 60 | H2SO4 | > 75% Glucose hydrolysis yields | (Bär et al. 2018) | |
Wheat straw | 60%, w/w | – | 200 | 60 | – | Organosolv lignin | (De Wild et al. 2012) | |
Silver birch | 50% or 60% | 1:10 | 180 or 200 | 15 or 30 | H2SO4 | Cellulose content increased from 37.1 to 69.2%, with 12.96% hemicellulose, and 13.24% lignin content | (Monção et al. 2021) | |
Isobutanol | Beechwood | 50% v/v aqueous isobutanol | 1:10 | 160 | 120 | Mild acid-free oxidative conditions | High delignification (97%), oligosaccharide recovery in 43.3% aqueous fraction, 92.6 wt% cellulose-rich pulp | (Karnaouri et al. 2021) |
1-Butanol | Sorghum bagasse | 25% | 6:80 | 200 | 60 | H2SO4 | 84.9% and 15.3% highest cellulose and low lignin content, respectively | (Teramura et al. 2018) |
Methanol | Cauliflower stalk | 100% | – | 121 | 30 | Sodium acetate | 77.85 ± 0.58% cellulose yield and 1.07 ± 0.71% hemicellulose yield | (Majumdar et al. 2019) |
Cauliflower leaf | 100% | – | 121 | 30 | Sodium acetate | 74.97 ± 0.39% cellulose yield, 6.84 ± 0.81% hemicellulose yield | ||
Hazelnut skin | 50% v/v | – | 130, 160, 200 | 60 | H2SO4 | Lignin content reduction from 39.66 to 34.73%, increase in bioavailable sugars | (Oliva et al. 2021) | |
Glycerol | Eucalyptus wood | 56% aqueous glycerol | 1:10 | 200 | 69 | – | 65% lignin solubilisation, 99% cellulose retention in biomass | (Romanà et al. 2016) |
Wheat straw | 70% aqueous glycerol | 1:20 | 220 | 180 | – | 95% cellulose retention, 65% lignin removal, 70% hemicellulose removal | (Sun et al. 2015) | |
Sugarcane bagasse | 70% industrial glycerol | 1:20 | 200–240 | 60–300 | – | > 65% lignin and > 80% hemicellulose removal, > 95% cellulose retention | (Sun et al. 2016) | |
THFA | Hybrid Pennisetum | – | 1:12 | 100 | 120 | H2SO4 | 87.5% enzyme digestibility, recovered 80.8% total glucan in the untreated HP | (Tan et al. 2019) |
Ethylene glycol | Degraded empty fruit bunch | 50% v/v ethylene glycol | 1:10 | 80 | 45 | NaOH | 75.1% High delignification, 81.5% hemicellulose removal, and 90.4% cellulose recovery | (Chin et al. 2020a) |
Bagasse | – | 1:10 | 110–150 | 60 | HCl | ~ 99.3% hemicellulose and ~ 67.1% lignin removal, 94.3%, glucose recovery yield | (Wei et al. 2021) | |
– | 1:10 | 110–150 | 60 | NaOH |  ~ 90.9% lignin removal and ~ 28.8% hemicellulose degradation, 92.5% glucose recovery yield | |||
Rice straw | 90% ethylene glycol | 1:20 | 150 | 30 | AlCl3 | 88% delignification, 90% hemicellulose removal, 100% cellulose recovery | (Tang et al. 2019) |