Carbon dioxide submarine storage in glass containers: Life Cycle Assessment and cost analysis of four case studies in the cement sector

This paper describes the potential application of a new patented technology for the storage of carbon dioxide (CO₂) in glass containers into the deep seabed (confined submarine carbon storage (CSCS)) to cement plants located in four different locations in the world. This technology is based on the bottling of liquid CO₂ at high pressure inside capsules made of glass that are delivered to the bottom of the ocean via a proper pipeline. A Life Cycle Assessment that considers all the stages of the process and 13 impact categories, with a focus on climate change, shows an impact in the four case studies between 0.084 and 0.132 ton of CO₂ equivalent (eq) per ton of CO₂ stored. Since carbonation of cement materials over their life cycle is a significant and growing net sink of CO₂, the capture and storage of CO₂ emissions generated during the production of cement might lead to negative emissions. A cost analysis was also performed, including the capital costs and the operational costs, even considering the funding structure through financing and equity. The costs of the four case studies are from 16 to 29 $/tCO₂. Although further work is needed to assess in detail some aspects of the design, the result of this stage of the research allows concluding that the application of the CSCS in cement plants is an interesting option for achieving negative emissions, even if limited due the slowness of CO₂ uptake during the lifetime of cement materials.