New Coal Technology Could Help Climate - US Expert
Author: Alister Doyle, Environment Correspondent
Sargas, a privately-owned Norwegian group which cooperates with Germany's Siemens AG, said its technology can clean more than 90 percent of carbon dioxide emissions from a gas-fired or coal-fired plant, at lower costs than its rivals.
"The combination of technology which is basically mature and able to capture carbon dioxide at a small differential cost makes it very attractive," said Gregory McRae, a professor of chemical engineering at the Massachusetts Institute of Technology (MIT).
McRae, who is studying "clean coal" systems, accompanied Sargas leaders on Wednesday when they outlined the technology to Norway's ministers of Energy and Industry after Siemens certified that the process was feasible.
"As engineers, and interested in the environment, we're looking for technologies which are now cost effective and which allow capture of carbon dioxide," said McRae, who is paid as a consultant to Sargas.
Many nations are trying to limit emissions of carbon dioxide, the main gas blamed by most scientists for global warming that could spur more droughts, more powerful storms and raise sea levels by almost a metre by 2100.
And many countries, from the United States to China, depend on coal which is a heavily polluting fossil fuel. "China is building one 500-megawatt power plant a week without any capture technology," McRae said.
He said Sargas technology could be interesting to developing nations such as China or India, which might have to limit emissions of carbon dioxide in coming years, and to industrial nations such as the United States that are big coal burners.
The UN's Kyoto Protocol now obliges most rich nations to cut emissions of carbon dioxide by 5.2 percent below 1990 levels by 2008-12. Washington pulled out of Kyoto in 2001, saying it was too expensive and wrongly excluded developing nations.
Sargas reckons that the cost of generating electricity from will be 25 percent higher with its carbon capture system -- known as modified pressurised fluidised bed combustion -- than if generated with no capture. Coal is cheaper than gas, however.
"The idea is that by burning coal under pressure you can reduce the size of the power plantand you can make it easier to capture the carbon dioxide," McRae said of the system.
"The cost is substantially lower than of competing capture technologies, which we believe are less mature," Sargas chairman Henrik Fleischer told Reuters.
He said Sargas technology cost less than rival integrated gasification combined cycle power plants.
Sargas said a coal-fired plant using its technology could produce electricity for US$0.049 per kilowatt/hour, assuming a coal price of US$65 a tonne. Gas-generated electricity would cost twice that amount, partly due to higher gas costs.
Carbon dioxide could either be buried beneath the ground or pumped into oil reservoirs to help keep up pressure and force more oil to the surface.
Siemens said in a statement that it had tested the Sargas target of cutting carbon dioxide by 90 percent and nitrous oxide emissions to five parts per million from a gas-fired plant. Siemens said similar figures would apply to a coal-fired plant.