User:Milton Beychok/Sandbox

MIT

Today, and independent of whatever carbon constraints may be chosen, the priority objective with respect to coal should be the successful large-scale demonstration of the technical, economic, and environmental performance of the technologies that make up all of the major components of a large-scale integrated CCS system — capture, transportation and storage. Such demonstrations are a prerequisite for broad deployment at gigatonne scale in response to the adoption of a future carbon mitigation policy, as well as for easing the trade-off between restraining emissions from fossil resource use and meeting the world’s future energy needs

What is needed is to demonstrate an integrated system of capture, transportation, and storage of CO2, at scale. This is a practical goal but requires concerted action to carry out. The integrated demonstration must include a properly instrumented storage site that operates under a regulatory framework which includes site selection, injection and surveillance, and conditions for eventual transfer of liability to the government after a period of good practice is demonstrated. An explicit and rigorous regulatory process that has public and political support is prerequisite for implementation of carbon sequestration on a large scale. This regulatory process must resolve issues associated with the definition of property rights, liability, site licensing and monitoring, ownership, compensation arrangements and other institutional and legal considerations. Regulatory protocols need to be defined for sequestration projects including site selection, injection operation, and eventual transfer of custody to public authorities after a period of successful operation. These issues should be addressed with far more urgency than is evidenced today.

CO2 capture and sequestration (CCS) is the critical enabling technology that would reduce CO2 emissions significantly while also allowing coal to meet the world’s pressing energy need.

The scale of CCS required to make a major difference in global greenhouse gas concentrations is massive. For example, sequestering 5 Gt of carbon dioxide requires injection of about 65 million barrels per day (about 10 x 10⁶ cubic neters per day) of supercritical CO2 from about 800 1000MW of coal plants.

Amine absorption and regeneration. Cool, dry and compress CO2 to 150 atmosphers (15 MPa). Compression to super critical fluid. Reduces plant thermal efficiency by 5% (amine) plus 4% (compression). Thus from 34% down to 25%.

CCS = Carbon Capture and Sequestration. Carbon sequestration is the long term isolation of carbon dioxide from the atmosphere through physical, chemical, biological, or engineered processes. The largest potential reservoirs for storing sequestered carbon are the deep oceans and geological reservoirs in the earth’s upper crust.

•Increased use of nonhydropower renewables for electricity generation in the OECD economies. For nonhydropower renewables to provide 20 percent of the electricity consumed in the OECD economies in 2030, the use of renewables would have to increase by an average of 7.4 percent annually from 2010 to 2030, as compared with the 2.5-percent average increase in the IEO2008 reference case. The increase would yield 1 billion metric tons of abatement annually by 2030.

Alternatives for reducing CO2 (Chapter 7, DOE)

• Increases in nuclear electricity generation. According to the World Nuclear Association, the achievement of 740 gigawatts of installed nuclear electricity capacity by 2030—36 percent more than projected

in the IEO2008 reference case—is possible. If additional nuclear power displaced only coal, such an increase would achieve a reduction of about 1 billion metric tons annually by 2030.

•Increased use of hydropower and nonhydropower renewables for electricity generation in the non-OECD economies. Assuming that there are more opportunities for hydropower expansion in the non-OECD economies than in the OECD economies, if the combined use of hydropower and nonhydropower renewables in non-OECD countries grew by 3.5 percent per year from 2020 to 2030, as compared with 1.3 percent in the IEO2008 reference case, 1 billion metric tons of carbon dioxide emissions would be avoided annually by 2030.

•Increased use of renewable fuels for transportation. If new technologies were employed to minimize carbon dioxide emissions from input fuels and indirect emissions of other greenhouse gases, so that an additional 20 quadrillion Btu of biofuels was consumed in the transportation sector, assuming a life-cycle savings of 80 percent in carbon dioxide emissions compared to conventional petroleum, 1 billion metric tons of carbon dioxide emissions could be avoided by 2030.

•Carbon capture and storage. It is unlikely that significant amounts of carbon capture and storage will be implemented before 2020. When the technology does become available commercially, its application to about 250 gigawatts of coal-fired generation capacity with a 90-percent removal rate would result in the mitigation of 1 billion metric tons of carbon dioxide emissions annually. The IEO2008 reference case does not include carbon capture and storage. Although there are some small projects in pilot phases around the world, the assumption is that without binding constraints on carbon dioxide emissions throughout the projection period there would be no economic incentive to engage in carbon capture and storage.

•Anthropogenic sequestration. The latest assessment by the Intergovernmental Panel on Climate Change estimates that about 3.7 billion tons carbon dioxide equivalent per year is sequestered by anthropogenic activity, including projects such as reforestation and other land-use programs. A 27-percent increase in such activity by 2030 would represent an emissions reduction of 1 billion metric tons.