Investigation of Technical Issues for Adsorbent-Based Electrochemical Marine Carbon Dioxide Removal

Storms, torrential rains, and forest fires caused by climate change are occurring frequently. This year, Japan has also experienced large-scale forest fires that have caused significant economic losses. In order to mitigate climate change, it is necessary to reduce greenhouse gas emissions and remove carbon dioxide in the atmosphere. Although emission reduction efforts are underway around the world, they do not seem to be progressing as targeted because of the need for energy for economic development. On the other hand, since CDR (carbon dioxide removal) removes already released into the atmosphere, research and development could greatly accelerate this process. This paper introduces the different types of CDR, and in particular, describes an engineering method for capturing CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> from seawater. Furthermore, this paper introduces the possibility of constructing a system for the amount of CO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> that needs to be captured in Japan by this method. The technology to realize the system and its challenges will be described, with particular reference to the scaling issues that need to be solved as a priority in the operation of the core electrodialysis system. Since scaling is caused by the formation of magnesium hydroxide, two ideas for reducing scaling are presented.