Table 4 Experimental design used to investigate the pretreatment step
Condition | Temperature (°C) | Residence time (min) | pHa | Coded units | ||
|---|---|---|---|---|---|---|
1 | 200 | 10 | 3 | 1 | 1 | 1 |
2 | 200 | 10 | 2 | 1 | 1 | − 1 |
3 | 200 | 5 | 3 | 1 | -1 | 1 |
4 | 200 | 5 | 2 | 1 | -1 | − 1 |
5 | 190 | 10 | 3 | − 1 | 1 | 1 |
6 | 190 | 10 | 2 | − 1 | 1 | − 1 |
7 | 190 | 5 | 3 | − 1 | − 1 | 1 |
8 | 190 | 5 | 2 | − 1 | − 1 | − 1 |
9 | 195 | 7.5 | 1.6 | 0 | 0 | − 1.8 |
10 | 195 | 7.5 | 3.4 | 0 | 0 | 1.8 |
11 | 195 | 3 | 2.5 | 0 | − 1.8 | 0 |
12 | 195 | 12 | 2.5 | 0 | 1.8 | 0 |
13 | 186 | 7.5 | 2.5 | − 1.8 | 0 | 0 |
14 | 204 | 7.5 | 2.5 | 1.8 | 0 | 0 |
15 | 195 | 7.5 | 2.5 | 0 | 0 | 0 |
16 | 195 | 7.5 | 2.5 | 0 | 0 | 0 |
17 | 195 | 7.5 | 2.5 | 0 | 0 | 0 |
18 | 195 | 7.5 | 2.5 | 0 | 0 | 0 |