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Ethanol production from cassava 63
2.0
26
24
Conventional
Ethanol
12
10
Cell (10 8 cells/ml)
1.5
1.0
.5
22
20
18
16
14
Cell
TSS
8
6
4
Ethanol (%, v/v)
12
2
0.0 10
0
Total
0 12 24 36 48
soluble solids
(Brix)
Time (hr)
2.0
26
12
1.5
24
22
Rhizozyme TM
Ethanol
10
Cell (10 8 cells/ml)
1.0
20
18
16
Cell
8
6
4
Ethanol (%, v/v)
.5
14
12
TSS
2
0.0 10
Total
soluble solids
(Brix)
0 12 24
Time (hr)
36 48
Figure 2. Changes in total soluble solids (TSS), brix, cell count and ethanol during cassava fermentation by yeast in a conventional
(top) liquefaction and saccharification process and a simultaneous saccharification and fermentation (bottom) process using
Rhizozyme TM . The SSF process required 25% less time (from Keawsompong et al., 2003).
0
28-32°C and is pumped into the fermentor.
Fermentation is the critical step in a distillery. It
is here that yeast converts sugar to ethanol,
carbon dioxide and other by-products.
Saccharomyces cerevisiae is typically used for
ethanol fermentation from cassava. During
fermentation, foaming can be a problem. The
fermentation media from cassava is usually low
in nitrogen, so yeast food or other nitrogen
sources should be used. Fermentation time is
normally of 56-72 hrs.
As with other fermentations, infections are of
concern. Lactoside TM , a broad-spectrum
antimicrobial, is added at 2-3 ppm in fermentors
in some distilleries.
DISTILLATION
Distillation procedures are those standard
throughout the industry. Cassava poses no
special problems in the still. Yield is around 94-
95% of calculated values.
References
Akpan, I., M.J. Ikenebomeh, N. Uraih, and C.O.
Obuekwe. 1988. Production of ethanol from
cassava whey. Acta Biotechnol. 8(1):39-45.
Balagopalan, C. 2002. Cassava Utilization in
Food, Feed and Industry. CCAB International.