Table 3.
Comparison of investigated methods in terms of lignin type, solvent and antisolvent consumption, yield and stability at different pH and ionic strength values.
| Method | Source | Lignin Type 1 | Solvent 2 (L) | Antisolvent 2 (L) | Yield (%) | pH Stability | Ionic Strength Stability (mM NaCl) |
|---|---|---|---|---|---|---|---|
| Solvent shifting (solid particles) | [17] | AL | THF (1) | H2O (2.03) | - | <12 | - |
| [37] | KL | THF (0.1–1) | Dialysis with H2O | - | 7.4 | - | |
| [34] | KL | THF (0.1–1) | Dialysis with H2O | - | 4–12 | <500 | |
| [38] | OS | THF (0.01–0.1) | H2O (0.090–2) | - | - | - | |
| [43,56] | OS | Acetone (0.2) | H2O (1.8) | - | 3.5-8 | <70 | |
| [40] | EHL/OS | Acetone/H2O (0.1–10) | H2O (0.4–40) | - | - | - | |
| [41] | AL/Dioxane | Acetone/ H2O (0.1) | H2O (0.05) | 33–63 | - | - | |
| [44] | EHL | DMSO (0.333–0.488) | Dialysis with H2O | 41–90.9 | 4–10 | - | |
| Solvent shifting (hollow particles) | [51] | EHL | THF (0.5–2) | H2O (2–8) | - | 3.5–12 | - |
| [52] | KL | THF (0.2–2) | H2O (1.8–18) | - | - | - | |
| [54] | KL | Ethanol (0.4) | H2O (3.9) | - | - | - | |
| [53] | KL | Dioxane (0.3) | H2O (2.4) | - | - | - | |
| pH shifting (solid particles) | [43,56] | KL | EG (0.2) | 0.025M HNO3 (0.04–0.12) | - | 2–10.5 | <300 |
| [23] | EHL | EG (0.02) | 0.25M HCl (0.05) | ~10 | - | - | |
| [59] | AL | EG (0.025) | 0.1M HCl (0.001) 3 | - | - | - | |
| [16] | KL | EG (0.02–0.18) | 0.25M HCl (0.03) | - | 6–9 | - | |
| [16] | KL | H2O/NaOH (2) | 0.25M HNO3 (0.18) | - | instable | - | |
| [59] | AL | H2O/NaOH (0.011) | 0.25M HNO3 (to pH 1.9) | - | - | - | |
| Mechanical treatment | [92] | KL | H2O (0.2) | - | - | - | - |
| [36] | AL | H2O (1.4) | - | - | - | - | |
| Ice segregation | [98] | AL | DMSO (0.2–5) | Dialysis with H2O | - | 10.5 | - |
| [97] | AL | H2O/NaOH (3.3–10) | - | - | - | - | |
| Aerosol processing | [114] | AL | H2O (0.05–0.2) | - | >60 | - | - |
| KL/OS | DMF (0.05–0.2) | - | >60 | - | - | ||
| Electro-spinning | [124] | OS | Ethanol (0.0013) | - | - | - | - |
| [120] | KL/OS/PL/LS | DMF (0.001–0.01)H2O (0.001–0.01) | - | - | - | - | |
| [129] | KL | PVA/H2O (0.002) | - | - | - | - | |
| CO2 precipitation | [135] | KL | DMF (0.008–0.018) | CO2 (0.47–1.89 kg) | 51–88.3 | - | - |
| [22] | OS | Acetone (2) | CO2 (41 kg) | - | - | - |
1 Kraft lignin (KL), Organosolv lignin (OS), Enzymatic hydrolysis lignin (EHL), Lignosulphonate (LS), Pyrolytic Lignin (PL); 2 based on 1 g initial lignin; 3 additional crosslinking with 30 mL 0.4 wt % glutaraldehyde.