Mineral Carbonation for Permanent Sequestration of CO2
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Materials chemistry (MPMCN), MSc
Publicerad
2023
Författare
Duda, Simon
Körner Acevedo, Ivar
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Carbon Capture and Storage (CCS) is an important tool for combating the ongoing climate crisis. In this
thesis, a CCS method known as mineral carbonation has been studied, with the aim to assess the feasibility
of using mine tailings for CCS via indirect mineral carbonation, as well as to estimate the economic viability
of a corresponding upscaled industrial process.
Mine tailings from three Swedish and Finnish mines were leached with HCl or NH4HSO4 at different temperatures.
After filtration, pH was adjusted to 9 and 10 with NH4OH, with filtering steps at pH 5, 7, 9 and
10 to investigate possibilities for byproduct recovery. Lastly, carbonation with 15 vol% CO2 was conducted
at 35 °C with solution alkalinity left to decrease to a stop condition of pH 8. Solid samples were analyzed
with PXRD, liquid samples with ICP-OES. Carbonation efficiencies, amounts of captured CO2 per tonne
feedstock and CO2 capture efficiencies were calculated.
Higher leaching temperature was found to promote extraction of Mg, whereas the correlation for Ca was
unclear. HCl produced higher extraction yields than NH4HSO4. Byproduct recovery was not successful upon
pH adjustment, partly due to insufficient amounts of solid precipitates for PXRD analysis. Carbonation of
the extracted Ca was successful and relatively fast, while carbonation of Mg was slow and unsuccessful when
starting at pH 9.
In the technoeconomic assessment, calculations were made in terms of operating expenses (OpEx) for an
industrial process which mimics the laboratory procedure in this thesis. While heating was found to be the
highest source of energy demand, the cost of chemicals for leaching and pH adjustment was identified as the
single largest expense. Therefore, recycling the chemicals is crucial if an economically viable process is to be
developed.
Mine tailings from the Kaunis Iron mine in Pajala and the Boliden mine in Garpenberg can be feasible for
mineral carbonation, much depending on the reaction parameters. Future studies should focus on further
mapping of the reaction parameters’ influence on the carbonation and sequestration efficiencies, as well as
on finding feasible ways to recycle at least 95 % of the make-up chemicals.
Beskrivning
Ämne/nyckelord
mineral carbonation , CO2 mineralization , mine tailings , carbon capture and storage , CCS , technoeconomic assessment