Potentiale zur energetischen Nutzung von Biomasse in der ... - EPFL

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Considering the structure of bioethanol production as presented in Figure 9, a particular attention
was put on the effect of “farm-gate price of biomass” and plant size. According to the remarks
concerning non-transport feedstock cost, the variation range considered included significantly lower
values of that parameter, as biomass prices may already today be available at much lower prices and
may also become cheaper in the near future with the potential competition with foreign feedstocks
on the Swiss market. Optimal plant size in ethanol process designs has always been a much debated
issue, and is strongly dependent on a fine evaluation of transport feedstock costs. The question of
whether it is more beneficial to build many small-scale units or one large-scale unit is largely
dependent on local conditions, and this question of a centralized or decentralized production has
definitely not a unique nor a clear answer.
The results of the sensitivity analysis presented above are first presented in separate individual graphs
(Figure 10) to give an accurate picture of the effect of each parameter on the production cost of
ethanol. In order to compare the relative effects of the same parameters on the production cost of
ethanol, the same results are then presented on a unique graph (Figure 11). The latter allows to assess
which of the considered parameters plays the most significant roles.
Ethanol production cost [SFr/l]
Ethanol production cost [SFr/l]
Ethanol production cost [SFr/l]
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
2.20
2.10
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
3.00
2.50
2.00
1.50
1.00
0.50
0.00
Ethanol production cost vs. Price of biomass
0 50 100 150 200 250
Biomass price index [100 = 70.5 SFr/t]
(a)
Ethanol production cost vs. Interest rate
0 50 100 150 200 250
Interest rate index [100 = 10%]
(c)
Ethanol production cost vs. Plant size
0 50 100 150 200 250 300 350
Plant size index [100 = 47.5 Ml/yr]
(e)
Ethanol production cost [SFr/l]
Ethanol production cost [SFr/l]
Ethanol production cost [SFr/l]
2.30
2.20
2.10
2.00
1.90
1.80
1.70
1.60
1.50
1.40
1.30
1.20
1.10
1.00
1.52
1.51
1.50
1.49
1.48
1.47
2.20
2.00
1.80
1.60
1.40
1.20
1.00
Ethanol production cost vs. Equipment cost
0 50 100 150 200 250
Equipment cost index [100 = 96.8 MSFr]
(b)
Ethanol production cost vs. Price of by-products
0 50 100 150 200 250
By-products price index [100 = 0.076 SFr/kWh]
(d)
Ethanol production cost vs. Conversion efficiency
0.80
50% 55% 60% 65% 70% 75% 80% 85% 90% 95% 100%
Conversion efficiency
Figure 10 Results of the sensitivity analysis on separate individual graphs for each parameter.
(f)