1. Introduction - Firenze University Press

GJ/tCO2 during pilot scale tests, with 90% capture efficiency. Apart from the capture, other cost
factors considered are:
Compression and cooling of the CO2
Shipping
Intermediate storage facilities
Injection into underground storage (including pressurisation to 120 bar)
This would lower the efficiency of the power plant by 10-13 percentage units. In terms of cost (and
by deduction, energy), the capture was estimated to account for the largest part, with 50 – 80% of
the total costs related to CCGS. Transporting the CO2 was estimated to account for 5 – 35% of the
total costs, and storage for 5 – 25%.
This paper explores another possibility for sequestering the CO2 emitted by the Meri-Pori power
plant, namely CO2 mineralisation, using mineral resources located not too far from the power plant.
There are several motivations for this:
It is known for quite some time (and repeatedly confirmed) that underground storage capacity is
not available in Finland [e.g., 6,7], while the same appears to hold for the Baltic region in
general (apart from CCGS capacity in Poland, a country with a lot of coal-derived CO2
emissions) [8]
Finland has vast resources of magnesium silicate-based mineral resources; assessments by the
Geological Survey of Finland typically mention 2-3 Gt CO2 storage capacity in minerals of the
Outokumpu-Kainuu region of central Finland alone [9-11]
Underground storage capacity in west-Russia may seem attractive but export of CO2 to outside
the European Economic Area is prohibited under the EU directive on CCS (which in fact
addresses only CCGS) [12]
Implementation of the above-mentioned EU directive on CCS in Finnish legislation is ongoing
and may result in CO2 underground storage being forbidden within Finland’s borders [13,14]
A five-year (2011-2015) research program on CCS is commencing in Finland coordinated by
Cleen Oy [15]. (The work reported here is outside that program, however.)
Finland (and at the moment primarily Åbo Akademi University, ÅA) has an extensive track
record on CO2 mineral sequestration R&D, with process routes that use either both magnesium
silicate-containing rock [e.g. 16,17, based on presentations at ECOS2010] or steelmaking slags
moving from lab-scale to demonstration scale [18].
Below, the feasibility of CO2 mineralisation applied to CO2 produced at the Meri-Pori power plant
using four types of minerals and the staged process route that is under development at ÅA is
assessed. Moreover, the combined removal and trapping of SO2 and CO2 from the flue gas is
investigated in an experimental study at the end of this paper. CO2 pre-capture would be omitted
from the CCS chain.
2. Considering the mineralisation option
Given that Finland does not possess underground storage sites, CCGS will always entail large
transport distances and export of the CO2 to Norway, Denmark or Poland. The location of the Meri-
Pori plant is indicated in Fig. 1.
Onshore pipeline transport of CO2 is significantly cheaper than shipping, for distances up to 1500
km (see Fig. 4.6 in [19]). With proven Mg-rich serpentine (Mg3Si2O5(OH)4) deposits as close as
~85 km from Meri-Pori, in Vammala, and olivine-type material located at Meri-Pori itself, not only
could transport costs be minimised, but the whole capture process could potentially be omitted if the
carbonation can be applied to the flue gas directly. Current CO2 mineral sequestration R&D focuses
more and more on direct carbonation with the CO2 containing gas, removing the expensive and
complicated (especially for gases that contain oxygen) capture step from the CCS chain. Compared
to pumping CO2 into saline aquifers, current mineralisation technology comes with an energy
84