Carbon Dioxide Capture and Storage

Abstract

Reducing CO 2 emissions from the use of fossil fuel is the primary purpose of carbon dioxide capture and storage (CCS). Two basic approaches to CCS are available.1,2 In one approach, CO 2 is captured directly from the industrial source, concentrated into a nearly pure form, and then pumped deep underground for long-term storage (see Figure 1). As an alternative to storage in underground geological formations, it has also been suggested that CO 2 could be stored in the ocean. This could be done either by dissolving it in the mid-depth ocean (1–3 km) or by forming pools of CO 2 on the sea bottom where the ocean is deeper than 3 km and, consequently, CO 2 is denser than seawater. The second approach to CCS captures CO 2 directly from the atmosphere by enhancing natural biological processes that sequester CO 2 in plants, soils, and marine sediments. All of these options for CCS have been investigated over the past decade, their potential to mitigate CO 2 emissions has been evaluated,1 and several summaries are available.1,3,4