Menlo Park, Calif., April 12, 2011 — A side-by-side comparison of the most promising technologies for advanced carbon capture of coal-fired emissions reveals that the processes are still costly, despite improvements, according to a new report from information and analysis provider IHS.
The IHS report, titled "Advanced Carbon Capture, SRI Consulting Process Economics Program," examined the technology and economics of 10 processes for the post-combustion capture of carbon emissions from electric power generation using pulverized coal.
"The scrubbing technologies currently moving through demonstration are very expensive and it's hard to see how to significantly bring down their cost," said Michael Arné, senior analyst at IHS and author of the report. "There are some promising new approaches on the drawing board, but they are at least 10 years away."
Robert LaCount, senior director, climate change and clean energy at IHS CERA, agrees that the processes are costly, particularly in the demonstration stages, but cites a recent IHS CERA report, titled "Carbon Capture and Storage: At a Critical Juncture," which says that, in addition to cost, there are more factors that put carbon capture and storage technologies at a disadvantage today.
"Carbon capture and sequestration is a crucial technology for meeting aggressive, long-term climate policy objectives," LaCount said. "However, through a coalescence of factors, CCS is at a disadvantage today — lower natural gas prices, technical and regulatory questions for CO2 storage, and an uncertain climate-change policy environment, are at the core of CCS's challenges."
"With that being said," LaCount added, "coal is currently the most significant fuel source for power generation." According to IHS, coal-fired generation accounted for 40 percent of the 20,000 terawatt-hours (TWh) of electricity generated worldwide but accounted for three-quarters of all the CO2 emitted by the global power sector.
Said LaCount, "It is clear that coal is currently a crucial fuel source, and at the same time, it bears a huge responsibility for GHG emissions. If the often mentioned 80 percent GHG reduction target is to be met by mid-century, CO2 from coal-fired generation will have to be captured and stored, and the technologies addressed in the Advanced Carbon Capture report will help industry better evaluate which technical options are most promising in order to meet emission targets."
"The prospect for reduction of CO2 cost using scrubbing processes is limited due to the significant power requirements and high capital costs for the separation and compression units," added Arné.
Advanced oxy-combustion has the potential for the lowest costs of any of the technologies examined, the study noted. The use of corrosion-resistant boiler tubes to eliminate the need for desulfurization in the flue-gas recycle loop has the potential to cut CO2 costs significantly. This approach has the added appeal of mitigating sulfur emissions in a "two for the price of one" remediation scheme.
"Advanced oxy-combustion, if used in conjunction with an ion-transport membrane instead of cryogenic air separation, could drive down costs even further, but such technology is still years away," said Arné. "The solution to making carbon capture economically viable is a technological challenge, which is something that the engineering community can solve — that's the good news. Technical improvements will be made to drive costs down, but to get to that point we'll need to see significant investments in ongoing research over time."