Table 1.
Yield and composition data (weight %) for P1000 soda lignin and Indulin AT Kraft lignins and their solvent fractions used in the present study.
| Component | Fraction | |||||
|---|---|---|---|---|---|---|
| Untreated lignin† | F01† | F02 | F03 | F04 | F05 residue | |
| Soda lignin | ||||||
| Yield (wt%)a | – | 31.1 | 19.4 | 23.4 | 8.7 | 17.4 |
| Carbohydratesb | 2.8 | 0.4 | 0.5 | 1.1 | 2.4 | 24.2 |
| Ash | 1.9 | 0.0 | 0.0 | 0.5 | 1.3 | 16.5 |
| Acid-soluble lignin | 4.8 | 5.8 | 2.6 | 1.5 | 0.9 | 1.5 |
| Acid-insoluble lignin | 83.5 | 76.5 | 87.4 | 89.7 | 93.8 | 44.6 |
| Other | 7.0 | 17.3 | 9.5 | 7.2 | 1.6 | 13.2 |
| Kraft lignin | ||||||
| Yield (wt%)a | – | 9.3 | 20.6 | 19.5 | 18.7 | 31.9 |
| Carbohydratesb | 1.5 | 0.2 | 0.2 | 0.3 | 0.9 | 4.5 |
| Ash | 2.1 | ND | ND | ND | ND | ND |
| Acid-soluble lignin | 0.5 | 1.2 | 0.7 | 0.3 | 0.2 | 0.2 |
| Acid-insoluble lignin | 87.4 | 54.2 | 91.1 | 91.8 | 93.5 | 77.9 |
| Other | 8.5 | ND | ND | ND | ND | ND |
Details of fractions are provided in Methods: F01, ethyl acetate fraction; F02, methyl ethyl ketone fraction; F03, methanol fraction; F4, acetone:water (4:1) fraction; and F05, residue. ‘Other’ materials are 100% minus the sum of the identified and quantitated components, and typically can be assumed to be proteins (P1000 Soda lignin) or possibly wood extractives (Indulin AT). ND, not determined.
awt%, dry wt basis of initial starting lignin.
bCalculated as polysaccharide. Error analyses < 5% relative.
†Data for untreated soda lignin and its ethyl acetate fraction (F01) have been previously published62.