Development and Evaluation of Innovative Strategies for Storage and Permanent Immobilization of CO2 in Geological Formations

The reduction of anthropogenic CO2 in the atmosphere is of paramount importance for the future world climate. Various available options for the sequestration of CO2 in the subsurface have been proposed and discussed. Both on the international and national level significant progress has been accomplished on this issue. Yet there is a continued need and also still unexploited potential for a judicious combination of carefully designed laboratory experiments and numerical simulations of the physical and chemical processes. The aim of this CO2Trap? project, funded by the German Federal Ministry of Education and Research (BMBF under grant 03G0614A, GEOTECHNOLOGIEN special program - Erkundung, Nutzung und Schutz des unterirdischen Raumes -), is to develop, study, and evaluate two alternative approaches for the subsurface deposition of CO2: Technology I: Precipitation of aqueous CO2 as calcium carbonate (CaCO3) in formations containing calcium sulphates (CaSO4) and feldspars. Technology II: Sorption of CO2 on (i) residual coal and (ii) waste coal dust or sludge from coal processing plants in abandoned coal mines. As an additional, overriding issue relevant for all options of underground storage of CO2 we propose to study the long-term effects of supercritical CO2 gas and dissolved aqueous CO2 on the sealing properties of typical cap rocks above potential CO2 storage formations.

The CO2TRAP project was successfully completed in May 2008 and initiated these follow-up projects:

CO2 Seals

Integrity of sealing rock formations for CO2 storage
http://www.co2seals.de

CO2SINUS

CO2 Storage in in situ Converted Coal Seams
http://www.co2sinus.org

ALCATRAP

Optimisation of CO2 binding by reaction with alkaline residual materials through the ALCATRAP process
http://www.hydro.uni-bayreuth.de/pros/detail.php?lang=de&id=32