Potential Application of CCS Technology for Reducing the Carbon Footprint Created during Deepsea Mining Operations

Since some of the successful pilot tests carried out in the late 1970s, deepsea mining of high-value minerals, such as cobalt and rare-earth elements has been receiving renewed interest. The water depth range in which to operate a deepsea mining project is beyond 4,000m up to 6,000m. Because of this, deepsea mining operation will require a significant of power, the generation of which would create a significant carbon foot print even using IMO rule compliant marine fuel engine-generators. One potential technology that could be utilized to reduce the footprint is to capture and inject the CO2 from the exhaust stream of the mining vessel power plant deep down near the seabed where the density of the CO2 is significantly higher than that of the seawater. The discharged CO2 “plume” would sink down to form “CO2 Lakes” in the troughs on the seabed. The key systems to be added onto the design of a deepsea mining vessel for the carbon capture are identified, but the main focuses of the paper will be on a riser configuration developed for the combined mining production and for the CO2 injection on a prospective deepsea mining project.