Table 3.
Xylose mass balance of maleic acid pretreatment of wheat straw.
| Run | Pre-treatment time (min) | Pre-treatment temperature (°C) | Maleic acid concentration (mM) | Xylose monomers in aqueous (%) | Furfural in aqueous (%) | Xylose oligomers in aqueous (%) |
Xylose in pressed material (%). Not corrected for a, b, and c |
Xylose in pressed material (%). Corrected for a, b, and c |
Total (%) |
|---|---|---|---|---|---|---|---|---|---|
| a | b | c | d | e | a+b+c+e | ||||
| 1 | 10 | 130 | 11 | 0 | 0 | 2 | 18 | 18 | 20 |
| 2 | 50 | 130 | 89 | 44 | 1 | 22 | 25 | 19 | 86 |
| 5 | 50 | 170 | 11 | 5 | 3 | 47 | 31 | 26 | 81 |
| 6 | 10 | 170 | 89 | 85 | 7 | 1 | 15 | 6 | 100 |
| 7 | 10 | 170 | 11 | 1 | 1 | 26 | 37 | 34 | 61 |
| 8 | 50 | 170 | 89 | 72 | 18 | 1 | 11 | 4 | 94 |
| 9 | 10 | 130 | 89 | 15 | 0 | 35 | 26 | 21 | 72 |
| 11 | 50 | 130 | 11 | 1 | 0 | 11 | 31 | 30 | 42 |
| 14 | 30 | 130 | 50 | 7 | 0 | 35 | 27 | 23 | 65 |
| 15 | 50 | 150 | 50 | 66 | 3 | 11 | 24 | 16 | 96 |
| 16 | 10 | 150 | 50 | 36 | 1 | 32 | 26 | 19 | 87 |
| 17 | 30 | 150 | 89 | 78 | 4 | 5 | 20 | 12 | 99 |
| 18 | 30 | 150 | 11 | 2 | 0 | 11 | 32 | 30 | 43 |
| 19 | 30 | 170 | 50 | 75 | 10 | 4 | 17 | 9 | 98 |
| c×6 | 30 | 150 | 50 | 58 (2.2) | 2 (0.1) | 17 (1.0) | 24 (0.3) | 17 (0.2) | 94 (1.4) |
c×6 = centre runs, six repeats. Average value given. Standard deviation between brackets. Percentages are expressed as xylose equivalents, as a fraction of total xylose equivalents present in untreated wheat straw.