Page 40 - Biofuels Refining and Performance

Energy and Its Biological Resources 23

T C
H H
Y L
L O 2H +
H 2 O Ferredoxin
A R H 2
O K O (Reduced) NO 3 − NH 3
2
O P ATP (NADP)
I L
D A
Carbohydrates B
M S CO 2
Light
E T SO 4 = H S I
2
S O
M H M
B NH A
E E N 2 3
T S
R E S
A R
N O
E
C
Y
S
T
S
Figure 1.7 Biophotolysis and electron flow system.

ferredoxin from Spirulina, and hydrogenase of Clostridium pasteuri-
anum [3].

O → 4H 4e O
2H 2 2

4 Ferredoxin 4e → 4 Ferredoxin

4H 4 Ferredoxin → 2H 4 Ferredoxin
2
O Glucose → Gluconate H O 2
2
2
H O Ethanol → 2H O Acetaldehyde
2
2
2
The overall reaction is
Glucose Ethanol → Gluconate Acetaldehyde H 2
Two H are produced for each O produced (if not consumed by an
2
2
oxidase-type reaction as shown previously). Dr John Benemann of the
same university has also suggested that hydrogen and methane pro-
duction is possible by designing a two-stage system separated from each
other (see Fig. 1.8).