John T. Litynski

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 (CO 2 ) 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 CO 2 from point sources: post-combustion capture, pre-combustion capture, and oxy-combustion. Several processes are available to capture CO 2 , and new or improved processes are under development. However, CO 2 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 CO 2 capture process that can be retrofitted to existing power plants. Once captured, the CO 2 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.

CCS Activities Being Performed by the U.S. DOE

The United States Department of Energy (DOE) is the lead federal agency for the development and deployment of carbon sequestration technologies. Its mission includes promoting scientific and technological innovations and transfer of knowledge for safe and permanent storage of CO2 in the subsurface. To accomplish its mission, DOE is characterizing and classifying potential geologic storage reservoirs in basins throughout the U.S. and Canada, and developing best practices for project developers, to help ensure the safety of future geologic storage projects. DOE’s Carbon Sequestration Program, Regional Carbon Sequestration Partnership (RCSP) Initiative, administered by the National Energy Technology Laboratory (NETL), is identifying, characterizing, and testing potential injection formations. The RCSP Initiative consists of collaborations among government, industry, universities, and international organizations. Through this collaborative effort, a series of integrated knowledge-based tools have been developed to help potential sequestration project developers. They are the Carbon Sequestration Atlas of the United States and Canada, National Carbon Sequestration Database and Geographic System (NATCARB), and best practice manuals for CCS including Depositional Reservoir Classification for CO2; Public Outreach and Education for Carbon Storage Projects; Monitoring, Verification, and Accounting of CO2 Stored in Deep Geologic Formation; Site Screening, Site Selection, and Initial Characterization of CO2 Storage in Deep Geologic Formations. DOE’s future research will help with refinement of these tools and additional best practice manuals (BPM) which focus on other technical aspects of project development.