Table 6.
Dry weight, char and inorganic contents of the insoluble and precipitated fractions (Fig. 1, steps XI and XVI) recovered by chelation extraction
| Sodium citrate | Sodium carbonate | Sodium oxalate | Sodium succinate | Sodium acetate | Sodium chloride | Water | Sodium hydroxide | ||
|---|---|---|---|---|---|---|---|---|---|
| Insoluble % (w/w) | Dry | 94.5 ± 0.6 | 96.1 ± 1.0 | 96.8 ± 1.8 | 94.0 ± 0.9 | 93.7 ± 1.1 | 93.8 ± 0.9 | 93.1 ± 1.1 | 94.0 ± 0.8 |
| Char | 28.8 ± 0.9 | 28.5 ± 1.3 | 30.1 ± 0.7 | 29.9 ± 0.3 | 29.5 ± 1.8 | 30.3 ± 0.7 | 31.7 ± 1.5 | 31.1 ± 1.4 | |
| Ash | 6.6 ± 1.1 | 10.1 ± 1.4 | 13.0 ± 2.4 | 12.0 ± 0.6 | 12.8 ± 1.3 | 12.9 ± 1.0 | 12.3 ± 1.0 | 14.9 ± 1.3 | |
| Precipitated % (w/w) | Dry | 93.8 ± 0.8 | 95.0 ± 0.9 | 94.6 ± 1.7 | 95.0 ± 0.5 | 95.2 ± 0.5 | 95.0 ± 2.7 | 97.3 | 96.5 ± 0.9 |
| Char | 28.3 ± 1.5 | 28.5 ± 1.4 | 26.8 ± 2.3 | 29.0 ± 1.2 | 27.5 ± 1.3 | 30.9 ± 4.6 | 27.1 | 28.4 ± 2.3 | |
| Ash | 6.4 ± 1.1 | 6.0 ± 0.9 | 4.8 ± 1.9 | 5.4 ± 2.0 | 5.2 ± 1.8 | 4.1 ± 2.7 | 1.8 | 3.3 ± 1.9 | |
± indicates standard deviation. The number of measured sample duplicates was four for all samples except for the precipitated fractions with sodium succinate, sodium acetate and sodium chloride (three duplicates) and the precipitated fraction with water (one experiment)