1. Introduction - Firenze University Press

for biofuels and the investment cost. Fairly large amounts of CO2 can, however,be separated
at a low cost. This has a positive effect on both the global CO2 emissions and the economic
performance for BLGMF 2030 (where it is assumed that an infrastructure for CCS is
established). The BLGCC case is considerably less profitable compared to BLGMF, but also
less profitable than RBU:Electricity due to a large investment cost in relation to the additional
amount of electricity produced. BLGCC shows the greatest global CO2 emission reduction
potential in all scenarios for the year 2020. However, for the year 2030 RBU:CCS shows the
greatest CO2 emission reduction potential in all scenarios.
For the cases of lignin extraction as a means to debottleneck the recovery boiler, lignin valued
as wood fuel shows a poor economic performance with the exception of Scenarios 2 and 4
(with high wood fuel prices). Lignin valued as oil, however, has a very good economic
performance, even in the scenarios with a low oil price (Scenarios 1 and 2). Furthermore, it is
not highly influenced by any of the parameters studied outside the scenarios, and can
therefore be said to be a fairly robust investment. As stated, lignin can replace oil both as a
fuel and as a feedstock for production of material or chemicals. If, for example, lignin is
upgraded to a material at the mill, it is of course possible to get an evenhigher price than the
oil price depending on the type of material. However, the cost and energy demand for
upgrading will then also have to be taken into consideration.
Investing in a recovery boiler upgrade and new turbines gives quite similar results for both
global CO2 emissions and net annual profit in the different scenarios. The possibility to
capture CO2 from the boiler flue gases yields a large CO2 reduction potential. However, the
profitability of capturing the CO2 is strongly dependent on the CO2 charge – e.g. it is only for
the scenarios having the highest CO2 charge, Scenarios 2 and 4, that RBU:CCS is more
profitable than RBU:Electricity.
5.2. Levels of support for green electricity and biofuels
From the results it can be concluded that the level of the green electricity support does not
significantly affect the economic performance of RBU:Electricity. For BLGCC the effect is
more pronounced, but is small compared to the effects of other parameter changes such as the
level of annuity factor. The relatively small effects are partly due to the assumed design of the
green electricity support system where only new production capacity is entitled to support.
The support for biofuels varies between the scenarios and is set at a level so that a stand-alone
biofuel production plant has the same willingness to pay for wood fuel as a coal power plant,
which is assumed to be a large volume price-setting user of wood fuel. This results in very
substantial levels of support for biofuels in Scenarios 1 and 2, which of course is questionable.
The resulting CO2 emission reduction in relation to the cost for society is relatively low, and
the money might be better used elsewhere. The sensitivity analysis (point e1) shows for
example the consequences of a 50% reduction of the level of support, which in Scenarios 1
and 2 results in a more reasonable level of the support. At this level, BLGMF is only the most
profitable option in Scenario 4 2030.
5.4. CCS
For 2030 CCS was assumed to be commercially available. The possibility to capture CO2 both
from the recovery boiler flue gases and, if in operation, from the bark boiler flue gases gives a
large CO2 reduction potential. However, the profitability of capturing the CO2 is strongly
dependent on the CO2 charge; e.g. it is only for the scenarios having the highest CO2 charge,
Scenarios 2 and 4, that RBU:CCS is more profitable than RBU:Electricity. If CCS is
available, this improves the global CO2 emissions effect and the economic performance for
BLGMF both in absolute terms and in relation to the other technologies. For Scenarios 2 and
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