66. Modeling Effects of Bicarbonate Release on Carbonate Chemistry of the North Sea

Julia Kirchner (1)*, Hans-Jürgen Brumsack (1), Bernhard Schnetger (1), Jörg-Olav Wolff (1), Karsten Lettmann (1)

1 Institute for Chemistry and Biology of the Sea (ICBM), University of Oldenburg, Germany

Background
Rising CO2-emissions accompanying the industrial revolution are presumably responsible for climate change and ocean acidification. Several methods have been developed to capture CO2 from effluents and reduce its emission. Among these a promising approach that mimics natural limestone weathering. CO2 in effluent gas streams reacts with calcium carbonate in a limestone suspension. The resulting bicarbonate-rich solution can be released into natural systems. In comparison to classical carbon capture and storage (CCS) methods this artificial limestone weathering is cheaper and does not depend on using toxic chemical compounds. Additionally there is no need for the controversially discussed storage of CO2 underground.

Methods
The unstructured grid finite volume community ocean model (FVCOM) was combined with a chemical submodul (mocsy 2.0) to model the hydrodynamic circulation and the carbonate system within the North Sea. With this tool we can predict the development of the continental-shelf carbonate system following external disturbances, e.g. the introduction of bicarbonate-rich waters.

Conclusions
The reduction of CO2-emissiosn becomes more important for European industries as the EU introduced a system that limits the amount of allowable CO2-emissions. Therefore large CO2 emitters are forced to find cheap methods for emission reduction, as they often cannot circumvent CO2-production. This method is especially of interest for power plants located close to the coast that are already using seawater for cooling purposes. Thus it is important to estimate the environmental effects if several coastal power plants will release high amounts of bicarbonate-rich waters into coastal waters, e.g. the North Sea.