CREATESPACE CO2-sequestration at the Swiss Molasse Basin, a Myth?: A Risk, Geology, Thermodynamic and Geothermic based pre-feasibility Study

CO2-Sequestration at the Swiss Molasse Basin, a Myth? A Risk, Geology, Thermodynamic and Geothermic based pre-feasibility Study This study was undertaken within the PSI-LEA Technology Assessment (TA) group’s involvement in the project CARMA (Carbon management in power generation). While the original scope of the study was to broaden and deepen previous analyses on accidental risks of Carbon Capture and Storage (CCS), the scope has been widened to include a site-specific assessment of the CCS potential for the location Utzenstorf (canton Berne, Switzerland), and subsequently an extrapolation for the whole Swiss Molasse Basin (SMB) and the adjacent Folded Jura was performed. In contrast to the first-appraisal study by Chevalier et al (2010) (“BfE-Study” of Diamond et al., 2010), our pre-feasibility study and their assumptions were developed to provide an alternative approach, which generally can be considered as more conservative (uncertainties 10-50%), and thus may serve as a lower boundary estimate of the potential for deep geological storage of CO2 in Switzerland. In addition, this study also provides an overview of the current state-of-the-art of equation of states (EOS) that are an essential element for the rational design and operation of CCS-processes, discusses potential synergies and conflicts of CCS and geothermal applications, and finally an estimation of the seal damage probability (SDP) for accidental leakage at a CCS site. Still missing for future investigations are cost-benefit estimations, sensitivity analysis, life-cycle assessment, sociological and environmental impact studies, more appropriate high pressure and temperature EOS of CO2, statistical modelling for “predicting” huge RG sandstones in USM sediments, geophysical detection procedures, 3D hydro geological modelling with CO2 fluids with MODFLOW in USM-sediments – and drillings etc. Less helpful are projects regarding carbonation reactions (“mineral trapping”) with minerals Mg-rich-Olivine or –Serpentine, because a lot of LCA studies have shown that this approach is rather insignificant method for CO2 mitigation. Ironically, our results in favour of USM sediments are so superb that we found the same range of number according to storage volume for CO2 (40% of BfE result) like the BfE study predicts. This similarity was not intended as an act of “sociological conformity”, rather another example of Talib’s “black [grey] swan” property of nature. We think that this study may help to define standard boundary conditions for a (hypothetic) CCS or geothermic regulatory authority in respect of safety margin (pressure built-up, injection rate, request for least sediment properties, water contamination issue). Although, the estimate of the CO2 storage potential is lower than in the BfE-study, it is still a substantial amount that could support several natural gas power plants, which appears sufficient considering the current planning of number of plants as well as that natural gas should serve as a bridging technology. However, the differences in suitability of different layers between the two studies are rather distinct, which should be further investigated in the future to become a clearer picture.