Coal plants are shutting down because of a rise in the availability of cheap natural gas, largely as a result of hydraulic fracturing, which is opening up new deposits of the fuel in places such as the Marcellus Shale Formation in Pennsylvania. That's good news for the global climate because burning natural gas emits roughly half as much CO2 as burning coal. But it's also bad news for the climate because burning natural gas still emits CO2. "There are more than enough discovered hydrocarbons that if we burn them, we fry the planet," Lord Nicholas Stern told this reporter at the Durban climate conference last December while discussing carbon capture and storage. "You can do CCS or you can bust the 2-degree target."
As a result of the shale gas revolution in the U.S., the bulk of new CCS projects worldwide are in China, which hopes to become a leader in the technology. Carbon capture and storage even snuck into the Communist Party's 12th Five-Year Plan. Eleven projects are under development across the country, ranging from advanced coal-fired power plants to a chemical plant that will turn coal into liquid fuel.
The Chinese are even considering investing in a CCS project in Texas, known as the Texas Clean Energy Project. But the key there, as in most ongoing projects, is not a price on CO2 pollution that emitters want to avoid, but a price on CO2 that is used to help get more oil out of the ground—a process known as "enhanced oil recovery," a potentially large market given the world's thirst for petroleum.
Oil to the rescue?
Carbon dioxide is already used to scour hard-to-reach oil below Texas. But it is pumped more than 800 kilometers in a pipeline from a naturally occurring formation of CO2 in Colorado, which can prove expensive. CO2 from a nearby CCS unit might lower the price of CO2, storing some of the greenhouse gas underground as a kind of unintended side benefit.
Such enhanced oil recovery can also be done with steam, of course, which is why breakthroughs on the capture side are still required to make CO2 even cheaper. That work spans everything from Advanced Research Projects Agency–Energy projects to an X PRIZE Foundation effort to raise the money to launch a carbon-capture prize, according to Christopher Frangione, senior director of the energy and environment prize group for the foundation.
Making capture cheaper is particularly needed when the process is applied to natural gas power plants. As it stands, U.S. Environmental Protection Agency greenhouse gas emission limits for new power plants are set at the level of the discharge of a new gas-fired power plant, thus there is no regulatory incentive to put CCS on a gas plant. But at some point that technology will be needed if the world is to avoid increasing greenhouse gas concentrations in the atmosphere, which is why France-based CCS technology provider Alstom is investigating it at its Mongstad facility in Norway. The chilled ammonia process from the Mountaineer demonstration will be used to capture CO2 from burning natural gas. "The technology is there and it can be done," argues Bob Hilton, vice president for government affairs at Alstom.