Life Cycle Assessment Performed on a CCS Model Case in Japan and Evaluation of Improvement Facilitated by Heat Integration

摘要

Carbon Dioxide Capture and Storage (CCS) is a technology for reducing the amount of CO_2 to be emitted into the air, by storing the CO_2. However, a CCS project itself emits some CO_2. Therefore, to estimate CCS's net CO_2 reduction effect, it is effective to apply life cycle assessment (LCA) to CCS projects. In this paper, we assumed a number of CCS project models to be feasible in Japan, and estimated the amount of CO_2 emissions to store one ton of CO_2 by applying LCA to the CCS projects. As a result, depending on the model case, 50% or more of the CO_2 amount to be stored was emitted. The study also revealed that approximately 80% of the CO_2 emissions at CCS-applied facilities derived from the energy consumed to re-heat the liquid absorbent that absorbed CO_2. The study also indicated that a substantial amount of CO_2 emissions can be reduced if heat integration is conducted between the production equipment and the CCS equipment for energy utilization, such as bleeding CO_2 from a power station and other production equipment.