538
D. Hara et al.
Table 35.7 DEA final results
Path
DEA result
Path
DEA result
Path
DEA result
A
0.04378
E
1.000
I
1.000
B
0.09473
F
1.000
J
0.6927
C
0.01673
G
1.000
K
0.02575
D
0.01216
H
0.9086
L
0.01896
35.4.3 DEA Results
Table 35.7 shows the DEA final results.
Overall, the hydrogen paths including the hydrogen production from woody
biomass is better than that including the sewage sludge process.
In addition, comparing the DEA results that have the same means of hydrogen
production and FC mobility, the hydrogen paths using MH were found to be better
than those using hydrogen compression except for the car case (Path A, B). Note that
the weight increment caused by the MH was not considered in this study.
Paths E, F and G are the most effective in the analysis of bicycle results. However,
the DEA results of Path H is also close to 1.000. Thus, these paths also have the
potential to be introduced as hydrogen paths of a FC bicycle.
Path I is also the most effective in the analysis of forklift results (I-L). This means
the introduction of woody biomass-derived hydrogen into the MH hydrogen forklift
process is the best hydrogen path balancing both exergy efficiency and environmental
impacts. Also, it is found that the hydrogen paths including hydrogen production from
woody biomass (Path I, J) are considerably more efficient than the paths including
sewage sludge processes (Path K, L) thanks to the large amount of CO 2 recovery
caused by the large demand of hydrogen.
In reviewing the car results, all paths resulted in poor efficiency values. Thus,
these processes have a low potential compared to other paths.
35.5 Conclusion
Product efficiency of the 12 hydrogen paths was compared. This included evaluation
of each path’s exergy efficiency and environmental impacts using DEA methodology,
We obtained the following significant results: (1) Low-pressure storage in the use
of MH has good potential to mitigate environmental impacts, (2) the exergy efficiency
in the case of MH mobility would be more advantageous, (3) small-scale mobility
(bicycle) with MH storage would obtain the maximum product efficiency (Path E,
G), and (4) the forklift with MH, which is fueled by Bio-H 2 of woody biomass origin,
would also obtain the maximum product efficiency (Path I).
D. Hara et al.
Table 35.7 DEA final results
Path
DEA result
Path
DEA result
Path
DEA result
A
0.04378
E
1.000
I
1.000
B
0.09473
F
1.000
J
0.6927
C
0.01673
G
1.000
K
0.02575
D
0.01216
H
0.9086
L
0.01896
35.4.3 DEA Results
Table 35.7 shows the DEA final results.
Overall, the hydrogen paths including the hydrogen production from woody
biomass is better than that including the sewage sludge process.
In addition, comparing the DEA results that have the same means of hydrogen
production and FC mobility, the hydrogen paths using MH were found to be better
than those using hydrogen compression except for the car case (Path A, B). Note that
the weight increment caused by the MH was not considered in this study.
Paths E, F and G are the most effective in the analysis of bicycle results. However,
the DEA results of Path H is also close to 1.000. Thus, these paths also have the
potential to be introduced as hydrogen paths of a FC bicycle.
Path I is also the most effective in the analysis of forklift results (I-L). This means
the introduction of woody biomass-derived hydrogen into the MH hydrogen forklift
process is the best hydrogen path balancing both exergy efficiency and environmental
impacts. Also, it is found that the hydrogen paths including hydrogen production from
woody biomass (Path I, J) are considerably more efficient than the paths including
sewage sludge processes (Path K, L) thanks to the large amount of CO 2 recovery
caused by the large demand of hydrogen.
In reviewing the car results, all paths resulted in poor efficiency values. Thus,
these processes have a low potential compared to other paths.
35.5 Conclusion
Product efficiency of the 12 hydrogen paths was compared. This included evaluation
of each path’s exergy efficiency and environmental impacts using DEA methodology,
We obtained the following significant results: (1) Low-pressure storage in the use
of MH has good potential to mitigate environmental impacts, (2) the exergy efficiency
in the case of MH mobility would be more advantageous, (3) small-scale mobility
(bicycle) with MH storage would obtain the maximum product efficiency (Path E,
G), and (4) the forklift with MH, which is fueled by Bio-H 2 of woody biomass origin,
would also obtain the maximum product efficiency (Path I).