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

Anhang 31
Bundesamt für Energie BFE
refining of products and combined cycle power generation. Tijmensen et al. (2002) estimated the
total short-term investment costs within the range 765–920 US$/kW th, input for a 367 MW th, input Fischer-
Tropsch combined cycle plant based on “once through” concept. The difference is due to the system
configuration and the type of particular equipment. In longer term perspective the investment costs
are expected to decrease by 25–35%, as a result of efficiency improvements, technology development
and increase in scale.
Biomass
60%
Capital
investment
27%
Figure 2 Breakdown of Fischer – Tropsch liquid biofuel production cost.
Variable
operating
costs
3%
Fixed
operating
costs
10%
Figure 2 shows the structure of the overall production cost of FT liquid biofuels in reference
configuration of the Fischer-Tropsch plant (400 MW th, input ). The price of biomass feedstock turns out to
be the major component of production cost, totalling 60%. However, these results are highly
dependent on the assumed level of the delivered biomass price. In the study of Tijmensen et al. (2002)
a significantly lower assumption of the biomass price (2.0 US$/GJ) leads to the estimation of FT liquids
production cost of around 14–16 US$/GJ in the near term perspective. This issue is investigated
further in more details through the sensitivity analyses and the projection of future costs.
Key determinants of FT liquids production cost
An analysis was carried out in order to evaluate the extent to which some variables may affect the
levelised production cost of the Fischer-Tropsch liquid biofuels, namely biomass feedstock price, total
capital investment cost and interest rate. This analysis was performed for the reference configuration
of the biofuel FT synthesis plant (400 MW th, input ) with combined power generation as depicted above.
The parameters’ values have varied within the range 50%–150%. The results of the sensitivity analysis
are presented in Figure 3 and the exact values of FT liquids production cost corresponding to varying
parameters are given in Table 2.
It can be observed that availability of a cheaper biomass resource allows for enhancing considerably
the overall economic performance of the Fischer-Tropsch plant. So, the assumption of biomass cost of
2.2 cts/kWh, which is close but still higher than the expected biomass price for comparative size FT
installations in the studies of Hamelink (2003) and Tijmensen (2002), reduces the production cost of
FT liquid biofuels to the level of 30.5 CHF/GJ (10.9 cts/kWh th ). Sensitivity to the equipment capital cost
is also significant, and it should be taken into account in the projection of production cost of future
generations FT plants. Impact of the interest rate on FT production cost is less significant among all
factors considered.