What price for carbon sequestration?
Carbon capture and sequestration is expensive but costs are going down for this critical component of carbon dioxide control
Pumping carbon dioxide into porous underground rocks might seem an obvious way of disposing of a gas that many people view as a prime culprit in global warming. But the high cost of capturing the gas and then storing it pose daunting challenges in developing and operating a viable carbon dioxide sequestration facility.
Despite the cost, carbon capture and storage is viewed as a critical tool to reducing atmospheric carbon dioxide, Brent Lakeman, business unit manager for the Alberta Research Council, told the Alaska Forum on the Environment Conference on Feb. 2.
“In our view CO2 capture and storage is certainly a critical technology,” Lakeman said. “… Right now it is a high-cost technology but … there are efforts to bring that cost down and … governments are making their expectations much more clear, both in Canada and in the United States, and elsewhere.”
Several toolsModels for future carbon dioxide concentrations in the atmosphere over the next 100 years suggest that tackling the rise in carbon dioxide levels will require a combination of different tools. And storage of waste carbon dioxide will be included in the toolbox.
“Typically about 25 to 30 percent of global emissions reductions need to occur from CCS (carbon dioxide capture and storage), otherwise the cost of the overall greenhouse gas mitigation toolbox becomes much too expensive and too difficult to deploy within that 100-year timeframe,” Lakeman said. “… The role of CCS is projected to increase over the course of the century.”
People need to have the CCS technologies in place in the next 10 to 15 years, he said.
And in oil producing areas like Alaska and Alberta there can be good synergies between carbon sequestration and the use of carbon dioxide for enhanced oil recovery.
The complete CCS process involves capturing the carbon dioxide from a gas stream; transporting the carbon dioxide by tanker, tanker ship or pipeline; and sequestration or storage of the carbon dioxide in underground rock formations. When eventually stored, the carbon dioxide occupies the pore spaces within a reservoir rock, where the gas may remain for millions of years — it’s not like storage in a cavern, Lakeman said.
And an important component of a CCS system is the measurement, monitoring and verification process that makes sure that the carbon dioxide remains stored in the underground rock reservoir.
“If you can’t show that the CO2 is remaining there, that’s not necessarily going to do much for greenhouse gas emissions,” Lakeman said.
And in addition to the CCS process itself, there are legal, regulatory, environmental and economic issues around both capturing and storing carbon dioxide.
Alberta situationLike Alaska, Alberta’s economy revolves around resource extraction and the use of carbon dioxide generating fossil fuels. But Alberta has the highest level of carbon dioxide emissions of any Canadian province, with 223 million tons of emission in 2004, Lakeman said. The production of oil sands has been showing a particularly high rate of growth and coal accounts for about 60 percent of electricity generation.
Unfortunately the more favorable areas for carbon dioxide storage lie some distance from the oil sands developments.
“So the challenge now is to transport high purity from that (oil sands) area to these areas where you can store significant amounts,” he said.
Meantime, there has been a carbon dioxide enhanced oil recovery project going on in neighboring Saskatchewan for the past seven or eight years, Lakeman said.
“That’s one of the leading EOR projects in the world and they are injecting over 1 megaton of CO2 per year, and they expect to be doing that over a 30-year life and get significant amounts of oil out of that formation,” he said.
In Alberta, it would be possible to achieve 70 percent of the province’s emission reduction objectives using carbon dioxide capture and storage, Lakeman said.
“Ultimately the focus is on developing our oil sands in an environmentally sustainable manner,” he said. “We can’t really do that, at least from a carbon point of view, without CO2 capture and storage.”
The Alberta government recently announced $2 billion in funding for large-scale carbon dioxide capture and storage demonstration projects, Lakeman said.
“That’s one of the most significant investments globally in this technology,” he said.
The hope is to have the projects up and running by 2015. Meantime, the regulatory framework and monitoring expectations are being developed, with liability issues associated with the projects also being addressed.
And as costs come down, Lakeman expects the use of carbon dioxide capture and storage to become increasingly widespread in North America.
“I expect to hear a lot more about this technology in the coming years, certainly in Alberta, and I think in the United States,” he said.