Process Design and Economics of On-Site Cellulase Production on Various Carbon Sources in a Softwood-Based Ethanol Plant
Table 1
Features of enzyme and ethanol productions. Both CEF and SSF are carried out in batch operation. Carbon source A: pretreated liquid fraction, B: pretreated liquid fraction and molasses, and C: pretreated liquid fraction and pressed pretreated slurry with a total WIS content of 1%, 2%, and 3%; +: 1.5-fold specific activity.
Reference
A
A+
B
B+
C1
C2
C3
Components into CEF, tonne/year
Hexosans
—
430
368
298
236
776
1374
1861
Pentosans
—
7
6
5
4
13
23
32
Hexoses
—
5133
3352
6242
4120
4812
4256
3805
Pentoses
—
1487
971
622
413
1394
1233
1102
—
806
690
558
442
1453
2575
3486
C5 ratio in , %
—
21
21
9
9
20
18
16
WIS content in CEF, %
—
0.5
0.7
0.8
0.9
1.0
2.0
3.0
Productivity of , FPU/(L·h)
—
70
107
154
230
75
84
93
Components into SSF, tonne/year
Hexosans
62980
62550
62612
62683
62745
62205
61606
61120
Hexoses
32634
27521
29304
30499
31228
27841
28397
28848
Yeast
3168
3160
3160
3160
3168
3144
3128
3112
Enzyme protein
1656
1104
1682
1121
1651
1642
1635
Mycelium
—
1727
1152
1754
1170
1722
1713
1705
, ktonne/year
117.98
117.55
117.61
117.68
117.74
117.19
116.59
116.09
Overall EtOH , L/dry tonne
270
254
260
263
266
254
254
254
hexosans and pentosans. /total sugar in ME. orresponds to an enzyme fermentation time of 108 h. yeast and enzyme productions and ethanol losses in the process. purchased enzyme preparation was assumed to contain 10% protein.