Table 3 Quantification of soluble and Klason lignin of eucalyptus barks (HGU an EG clones) after hot water extraction and each pretreatment step
Treatment | Lignin content | |||||
|---|---|---|---|---|---|---|
EG | HGU | Total lignin (%) | ||||
Soluble (%) | Klason (%) | Soluble (%) | Klason (%) | EG | HGU | |
Hot Water | 1.7 ± 0.1 | 23.4 ± 0.6 | 2.9 ± 0.9 | 24.2 ± 0.5 | 25.1 ± 0.3 | 27.1 ± 0.6 |
Acid 1% | 0.7 ± 0.1 | 31.3 ± 0.5 | 1.0 ± 0.3 | 31.0 ± 0.7 | 32.0 ± 0.3 | 32.0 ± 0.4 |
Acid 1% + NaOH 0.25% | 0.5 ± 0.2 | 30.2 ± 1.5 | 0.6 ± 0.2 | 21.7 ± 0.8 | 30.7 ± 2.2 | 22.3 ± 0.6 |
Acid 1% + NaOH 0.5% | 0.6 ± 0.2 | 27.5 ± 0.6 | 0.5 ± 0.2 | 22.1 ± 1.3 | 28.1 ± 0.3 | 22.6 ± 1.4 |
Acid 1% + NaOH 1% | 0.6 ± 0.3 | 23.3 ± 0.5 | 0.7 ± 0.3 | 17.6 ± 0.6 | 23.9 ± 0.2 | 18.3 ± 0.3 |
Acid 1% + NaOH 2% | 0.7 ± 0.1 | 16.3 ± 0.5 | 0.5 ±0.1 | 12.5 ± 0.5 | 17.0 ± 0.2 | 13.0 ± 0.2 |
Acid 1% + NaOH 4% | 0.4 ± 0.2 | 14.3 ± 0.5 | 0.5 ± 0.2 | 11.1 ± 0.3 | 14.7 ± 0.2 | 11.6 ± 0.1 |
NaOH 4% | 1.7 ± 0.5 | 17.6 ± 0.7 | 2.2 ± 0.6 | 16.2 ± 0.9 | 19.3 ± 0.3 | 18.4 ± 0.6 |