Feasibility of Distributed Carbon Capture and Storage (DCCS)

The concept of Distributed Carbon Capture and Storage (DCCS) for small scale CO2 sources, such as Distributed Energy Systems (DES), is proposed, and Carbon Storage in a Shallow Aquifer (CSSA), in which CO2 is stored in shallow aquifers as aqueous solution, is also studied as a technique for the DCCS. A conceptual design for the CSSA have been performed and the fundamental calculations in this study show that the dissolution capacity, that is, the amount of CO2 which can be dissolved into unit volume of water in a shallow aquifer is 10–35 kg-CO2/m3 in the range of the storage depth of 100–500 m. The dissolution capacity of the CSSA is less than 10% of the possible amount of CO2 stored by the ordinary CCS technique in which CO2 is stored in the supercritical condition. However, the CSSA is estimated to allow the CO2 storage at less than ¥3000/t-CO2 of the storage cost and more than 20-years of the injection period for CO2 sources of 1800–39,000 t-CO2/year, which correspond to the CO2 emissions from 0.1 to 10 MW DES. The required energy for the CSSA is estimated to be less than 10% of the energy generated by the CO2 sources.