| Pretreatment | Biomass changes | Advantages | Disadvantages | |||
| Cellulose | Hemicellulose | Lignin | ||||
| Physical | Ball mill | High crystallinity decrease | Not changed | Not changed | Crystallinity decrease | High energy consumption |
| Chemical | Diluted acid | Mild depolymerization | 80% - 100% removal | Mild removal | High xylans production | Hard acid recovery, corrosive, and high cost |
| Sodium hydroxide | Significant swelling | High solubility, >50% | High solubility, >50% | Effective esters removal | High cost | |
| ARP | Low depolymerization | High solubility, >50% | High solubility, ≈70% | Effective delignification | High cost | |
| Calcium hydroxide | Mild depolymerization | Significant solubility | Partial solubilization (≈40%) | Effective lignin and acetyl removal; low cost | Low solubulity | |
| Ozonolysis | No depolymerization | Low solubilization | High solubility, >70% | Effective delignification | High cost, and requires ozone | |
| Organosolve | Significant swelling | 80% - 100% removal | 80% - 100% removal | High xylans production, and Effective delignification | High cost for solvent recovery | |
| Biological | Biological | 20% - 30% of depolymerization | High solubility, >80% | Partial solubilization (≈40%) | Low energy consumption, and effective delignification | Loss cellulose, low hydrolysis rate |
| Combined | Steam explosion | Mild depolymerization | 80% - 100% removal | Mild removal, however the lignin structure is modified | Low energy consumption, and no recovery costs | Xylans degradation working as inhibitor compound |
| AFEX | Decrease in the crystallinity degree | High solubility, >60% | Partial solubilization (10% to 20%) | Loss xylans, and no inhibitor formation | Recovery of ammonia, is not effective for high lignin concentrations | |