iii
SummaryCarbon capture and sequestration (CCS) has the ability to dramatically reduce carbon dioxide (CO 2 ) emissions from power production. Most studies find the potential for 70 to 80 percent reductions in CO 2 emissions on a life-cycle basis, depending on the technology. Because of this potential, utilities and policymakers are considering the wide-spread implementation of CCS technology on new and existing coal plants to dramatically curb greenhouse gas (GHG) emissions from the power generation sector.However, the implementation of CCS systems will have many other social, economic, and environmental impacts beyond curbing GHG emissions that must be considered to achieve sustainable energy generation. For example, emissions of nitrogen oxides (NO x ), sulfur oxides (SO x ), and particulate matter (PM) are also important environmental concerns for coal-fired power plants. If the parasitic energy consumption of a carbon-capture plant increases the emissions of one or many of these other air pollutants, this should be considered when evaluating the technology's overall sustainability or environmental impact. While the majority of these "external" or "tangential" impacts are small on a global scale, it is still important to consider them to ensure the successful and sustainable implementation of CCS technology on a large scale. For example, several studies have shown that eutrophication is expected to double and acidification would increase due to increases in NO x emissions for a coal plant with CCS provided by monoethanolamine (MEA) scrubbing. Potential for human health risks is also expected to increase due to increased heavy metals in water from increased coal mining and MEA hazardous waste, although there is currently not enough information to relate this potential to actual realized health impacts. In addition to environmental and human health impacts, supply chain impacts and other social, economic, or strategic impacts will be important to consider. For example, if 90 percent of all the CO 2 generated by coal plant in the United States was captured and stored, using an MEA process, the annual consumption of MEA by U.S. power plants alone would be approximately 3.6 million tons, or 9 times the current U.S. consumption. Although 100 percent adoption of CCS by U.S. coal plants is not a realistic scenario, the exercise illustrates that the potential magnitude of the MEA demand created by more realistic adoption rates.Proper life-cycle assessments or analyses (LCAs) that are inclusive to all aspects of sustainability are a necessary tool for quantifying risk and feasibility of large-scale implementation of CCS. Life-cycle assessments have proven their usefulness in other systems, for example the sustainability of biofuels. For example, corn ethanol was championed as an alternative to importing foreign oil and a green way to increase rural employment. However, the competition of corn ethanol with food crops, its water use, and carbon debt were not well understood. If a full LCA or similar sustainability ass...