Table 3.
Impact of the operation parameters on the inhibitor and sugar level of the dry pretreatment in the helically agitated reactor
| Pretreatment conditions |
Inhibitors in the pretreated CS (g/100 g DM) |
Sugars in the pretreated CS (g/100 g DM) |
|||||
|---|---|---|---|---|---|---|---|
| Furfural | 5-HMF | Acetic acid | Glucose | Xylose | O-Glu | O-Xyl | |
| Changing temperature |
|
|
|
|
|
|
|
|
165°C, 2.5%, 3 minutes, 50 rpm |
0.13 ± 0.02 |
0.03 ± 0.00 |
0.45 ± 0.15 |
0.43 ± 0.01 |
7.58 ± 0.14 |
0.94 ± 0.06 |
9.28 ± 1.11 |
|
175°C, 2.5%, 3 minutes, 50 rpm |
0.24 ± 0.02 |
0.06 ± 0.00 |
0.55 ± 0.01 |
0.60 ± 0.01 |
10.05 ± 0.21 |
0.78 ± 0.03 |
6.42 ± 0.09 |
|
185°C, 2.5%, 3 minutes, 50 rpm |
0.63 ± 0.01 |
0.17 ± 0.01 |
0.81 ± 0.15 |
1.01 ± 0.02 |
10.20 ± 0.02 |
1.10 ± 0.44 |
2.84 ± 0.45 |
| Changing acid concentration |
|
|
|
|
|
|
|
| 185°C, 1.5%, 3 minutes, 50 rpm |
0.08 ± 0.01 |
0.04 ± 0.02 |
0.59 ± 0.06 |
0.45 ± 0.05 |
2.39 ± 0.00 |
0.72 ± 0.04 |
11.02 ±0.02 |
| 185°C, 2.0%, 3 minutes, 50 rpm |
0.18 ± 0.06 |
0.09 ± 0.07 |
0.58 ± 0.02 |
0.48 ± 0.00 |
5.34 ± 0.01 |
0.77 ± 0.00 |
8.45 ± 0.38 |
| 185°C, 2.5%, 3 minutes, 50 rpm |
0.63 ± 0.01 |
0.17 ± 0.01 |
0.81 ± 0.15 |
1.01 ± 0.02 |
10.20 ± 0.02 |
1.10 ± 0.44 |
2.84 ± 0.45 |
| 185°C, 3.0%, 3 minutes, 50 rpm |
0.89 ± 0.03 |
0.30 ± 0.03 |
1.29 ± 0.03 |
2.41 ± 0.02 |
9.99 ± 0.11 |
0.39 ± 0.01 |
0.81 ± 0.15 |
| 185°C, 3.5%, 3 minutes, 50 rpm |
0.78 ± 0.02 |
0.36 ± 0.07 |
1.24 ± 0.05 |
2.07 ± 0.02 |
7.85 ± 0.08 |
0.45 ± 0.01 |
0.80 ± 0.10 |
| 185°C, 4.0%, 3 minutes, 50 rpm |
0.84 ± 0.07 |
0.41 ± 0.17 |
1.22 ± 0.16 |
3.50 ± 0.02 |
8.34 ± 0.04 |
0.43 ± 0.07 |
0.45 ± 0.13 |
| Changing residue time |
|
|
|
|
|
|
|
| 185°C, 2.5%, 1 minute, 50 rpm |
0.39 ± 0.03 |
0.12 ± 0.01 |
0.73 ± 0.04 |
0.79 ± 0.00 |
9.89 ± 0.03 |
0.90 ± 0.08 |
2.56 ± 0.35 |
| 185°C, 2.5%, 3 minutes, 50 rpm |
0.63 ± 0.01 |
0.17 ± 0.01 |
0.81 ± 0.15 |
1.01 ± 0.02 |
10.20 ± 0.02 |
1.10 ± 0.44 |
2.84 ± 0.45 |
| 185°C, 2.5%, 5 minutes, 50 rpm |
0.80 ± 0.15 |
0.27 ± 0.03 |
1.09 ± 0.07 |
1.21 ± 0.02 |
7.91 ± 0.06 |
0.96 ± 0.11 |
1.35 ± 0.04 |
| 185°C, 2.5%, 10 minutes, 50 rpm |
0.99 ± 0.10 |
0.30 ± 0.02 |
1.13 ± 0.07 |
1.17 ± 0.01 |
6.27 ± 0.07 |
0.69 ± 0.04 |
0.37 ± 0.08 |
| Changing agitation rate |
|
|
|
|
|
|
|
| 185°C, 2.5%, 3 minutes, 10 rpm |
0.59 ± 0.04 |
0.18 ± 0.02 |
0.80 ± 0.10 |
0.99 ± 0.20 |
10.65 ± 0.35 |
0.49 ± 0.07 |
1.53 ± 0.00 |
| 185°C, 2.5%, 3 minutes, 30 rpm |
0.52 ± 0.02 |
0.19 ± 0.00 |
0.79 ± 0.11 |
0.97 ± 0.27 |
10.58 ± 0.23 |
0.78 ± 0.05 |
2.04 ± 0.04 |
| 185°C, 2.5%, 3 minutes, 50 rpm | 0.63 ± 0.01 | 0.17 ± 0.01 | 0.81 ± 0.15 | 1.01 ± 0.02 | 10.20 ± 0.02 | 1.10 ± 0.44 | 2.84 ± 0.45 |
The data in the pretreatment conditions column indicate the pretreatment temperature, acid concentration, and residual time, respectively. All the pretreatment experiments were carried out at 50 rpm. All the experiments were carried out in duplicate. Error was calculated as standard deviation. 5-HMF, 5-hydroxymethylfurfural; CS, corn stover; DM, dry matter; O-Glu, glucan oligomer; O-Xyl, xylan oligomer.