Evaluation of Alkali-Pretreated Soybean Straw for Lignocellulosic Bioethanol Production
Table 2
Effect of the concentration of sodium hydroxide for the alkali-pretreatment of the soybean straw and the efficiency of delignification.
NaOH
Compositions/100 g soybean straw
Delignification
Soluble
Insoluble
Cellulose
Hemicellulose
Lignin
[g]
[g]
[g]
[%]
[g]
[%]
[g]
[%]
Untreated soybean straw
-
44.2 ± 0.6
44.2
5.9 ± 0.5
5.9
19.2 ± 0.7
-
0.0 M
29.1 ± 0.5
70.9 ± 0.7
36.8 ± 0.8
51.9
5.7 ± 0.6
8.1
17.9 ± 0.5
6.9
0.5 M
52.0 ± 0.4
48.0 ± 0.5
31.9 ± 0.5
66.4
8.6 ± 0.7
17.9
12.6 ± 0.6
34.1
1.0 M
55.0 ± 0.3
45.0 ± 0.6
30.8 ± 0.7
68.6
6.9 ± 0.4
15.4
12.2 ± 0.5
36.5
1.5 M
57.5 ± 0.3
42.5 ± 0.5
30.0 ± 0.6
70.7
5.4 ± 0.2
12.7
11.9 ± 0.4
38.1
2.0 M
60.3 ± 0.6
39.7 ± 0.7
29.4 ± 0.6
74.0
4.1 ± 0.3
10.3
10.1 ± 0.6
47.4
2.5 M
62.8 ± 0.7
37.2 ± 1.2
27.4 ± 0.4
73.7
3.6 ± 0.2
9.7
10.1 ± 0.4
47.3
3.0 M
64.5 ± 1.2
35.5 ± 0.7
25.8 ± 0.5
72.9
3.2 ± 0.2
9.1
9.0 ± 0.4
50.0
g soybean straw is the weight of the total solid without the moisture content. and insoluble indicate soluble and insoluble solids in the total solids in soybean straw biomass. lignin content is the sum of acid-soluble and acid-insoluble lignin. percent of the relative delignification was calculated by the following formula: delignification (%) = 100 × (1 − ()). percent of each component means the relative amount in insoluble fraction.
