18 Carbon Capture for Coal-Fired Utility Power Generation: B&W's Perspective
Download citation file:
Changing climate and rising carbon dioxide (CO2) concentration in the atmosphere have driven global concern about the role of CO2 in the greenhouse effect and its contribution to global warming. Since it has become widely accepted as the primary anthropogenic contributor, most countries are seeking ways to reduce CO2 emissions in an attempt to limit its effect. This effort has shifted interest from fossil fuels, which have energized the economies of the world for over a century, to non—carbon-emitting or renewable technologies.
For electricity generation, the non-carbon technologies include wind, solar, hydropower, and nuclear, whereas low carbon technologies use various forms of biomass. Unfortunately, all current options are significantly more expensive than current commercial fossil-fueled technologies. Although use of wind and solar for power generation is increasing, they are incapable of supplying base load needs without energy storage capacity which is currently impractical at the scale required. The only technologies capable of sustaining base load capacity and potential growth are coal, natural gas, and nuclear. Nuclear has a long lead time to commercial operation, and concerns about long-term disposal of waste have not been resolved. Natural gas, although lower in carbon emissions than coal, still produces CO2, and its availability and price have proven to be volatile. Although recent discoveries have significantly increased availability of natural gas reserves, the pricing impact of higher cost extraction methods is not yet known.
In many countries, including the United States, coal is an abundant and low-cost source of fuel for generating electricity. Figure 18.1 shows the International Energy Agency's (IEA's) global electricity-generating capacity by fuel in 2007 and that projected for 2030. It should be noted that the current IEA forecast indicates more than a 70% increase in coal-based power generation by 2030. In the United States, coal currently fuels about 50% of power generation and represents an enormous infrastructure investment. Consequently, it will take considerable investment to move away from this base load fuel.