CKUA

[johnlw]

A cautionary tale of carbon capture
Underground sequestration of greenhouse gases remains a challenge for Nobel-winning scientist

Gordon Jaremko
The Edmonton Journal

Monday, December 10, 2007


EDMONTON / After earning a share in the 2007 Nobel Peace Prize by dedicating 15 years to underground storage of greenhouse gases, Stefan Bachu still refuses to promise disposal systems will work forever.

"I cannot guarantee it," the Alberta Geological Survey resident expert said in describing the state of the art of injecting carbon-dioxide into kilometre-deep porous rock formations.

"I haven't been there. I didn't check with a flashlight. We believe it should stay there."

Bachu's professional caution highlighted a stumbling block faced by global efforts to reduce waste-gas emissions blamed for global warming.

Who is responsible for making repairs, cleaning up damages and compensating victims if waste-gas storage sites spring leaks?

Alberta has nearly two decades of successes with about 50 disposal wells for "acid gas," a nasty byproduct of tapping natural gas contaminated with hydrogen sulphide and carbon dioxide. The oldest site has operated safely near the Edmonton suburb of Spruce Grove since 1990.

But greenhouse gas underground storage involves vastly higher volumes of waste, much larger geological containers, and coping with technical risks that will last for the rest of human history.

Alberta could store up to 10.3 billion tonnes of carbon-dioxide in porous rock reservoirs that have been tapped by oil and natural gas wells, the geological survey estimates.

Realism about identifying obstacles goes with Bachu's job as an engineer who packs a PhD and represents a research arm of the Alberta Energy and Utilities Board on the United Nations Intergovernmental Panel on Climate Change (IPCC).

He ranks among team leaders of 3,000 scientists from scores of countries who shared this year's Nobel with environmental moviemaker Al Gore for contributions to IPCC reports meant to guide environmental treaties and programs.

Unlike the former vice-president of the United States, the scientists labour quietly as mostly anonymous technical committee members. They settled for letters of thanks from the chairmen of their groups instead of medals and cheques from the Nobel Foundation.

The scientific products include a 500-page manual on Bachu's field of collecting carbon dioxide at industrial sites, such as power stations and refineries, transporting the waste gas in pipelines and "sequestering" or putting the stuff away in spongy rock formations.

Next comes a report on opportunities for building disposal systems on a large enough scale to make a difference to the climate outlook.

A plan will be presented to leaders of the world's eight top industrial countries for their 2008 G8 summit meeting in Japan.

Bachu is contributing to a "carbon sequestration leadership forum" created by the Paris-based International Energy Agency, a research arm of the Organisation for Economic Co-operation and Development.

As a 25-year veteran of Alberta's energy watchdog agency, Bachu is steeped in the economics as well as the science of his specialty.

Technology and geological knowledge is available for underground greenhouse gas storage, he said. The unsolved puzzle is who takes ultimate responsibility for risks of developing big waste disposal systems.

Taking on big liabilities includes thinking about worst-case scenarios. In the case of carbon-dioxide storage, the worst case happened in Africa within recent memory.

In 1986, a bottom layer of naturally carbonated water in a Cameroon volcanic crater lake, Nyos, rose to the surface. Like a colossal bottle of warm soda pop opened after a shaking, the lake released a misty fizz of carbon-dioxide that killed more than 1,700 villagers and thousands of cattle, birds and animals.

The cause of the disaster is still debated.

No amount of technical predictions that avoiding volcanic or earthquake areas and restricting greenhouse gas disposal to porous rock formations capped by hard shale or salt layers can erase scientific knowledge that nature is full of surprises.

"Industry is not willing to take an undefined, undetermined and unlimited liability of putting carbon dioxide in the ground," Bachu said.

Alberta has to develop a legal formula for greenhouse gas storage, Bachu said. He pointed to "templates" currently under international study, such as making industry build and maintain disposal sites in trade for government taking over liability for accidents.

His description of the obstacle against acting on environmental good intentions was confirmed in a new progress report by an Alberta group of 15 companies, including oilsands developers, working on plans for an "integrated carbon-dioxide network" known as ICO2N for short.

"There are several regulatory items that require attention before any CCS (carbon capture and storage) operations can proceed," the document said.

"These include defining CCS regulations on such items as the ownership of underground pore space and the issue of long-term liability for storage," the ICO2N group insists.

"Work has been done internationally on these issues and Canada should be able to draw from this expertise. However, it will take leadership from the province to develop the work plan and establish viable CCS regulation," the industry group said.