Progress and New Developments in Carbon Capture and Storage

Growing concern over the impact on global climate change of the buildup of greenhouse gases (GHGs) in the atmosphere has resulted in proposals to capture carbon dioxide (CO2) at large point sources and store it in geologic formations, such as oil and gas reservoirs, unmineable coal seams, and saline formations, referred to as carbon capture and storage (CCS). There are three options for capturing CO2 from point sources: post-combustion capture, pre-combustion capture, and oxy-combustion. Several processes are available to capture CO2, and new or improved processes are under development. However, CO2 capture is the most expensive part of CCS, typically accounting for 75% of overall cost. CCS will benefit significantly from the development of a lower cost post-combustion CO2 capture process that can be retrofitted to existing power plants. Once captured, the CO2 is compressed to about 150 atm and pipelined at supercritical conditions to a suitable storage site. Oil and gas reservoirs, because they have assured seals and are well characterized, are promising early opportunity sites. Saline formations are much more extensive and have a huge potential storage capacity, but are much less characterized. Several commercial and a number of pilot CCS projects are underway around the world. Information from these projects will form the basis for the development of CCS as a climate change mitigation strategy. These projects are contributing to the development of suitable regulations, determining best operating practices, improving mathematical models, and providing information to the public and other stakeholders. Based on current knowledge, CCS appears to be a promising option for reducing GHG emissions.