Even with the Clean Power Plan fully implemented, coal-fired generation is predicted to make up 22 percent of the U.S. power generation mix and natural gas will be 33 percent in 2030. Because fossil fuel-fired power plants are by far the largest emitters of carbon dioxide (CO2), which is causing dangerous climate change, some control of that CO2 is needed. Carbon capture and sequestration (CCS) is an available and critical means of pollution control for this industry and others. IA recent study found that if CCS is not included in the list of emission reduction options for the electricity sector globally, the ability to achieve target CO2 levels ever, is reduced by 0.5°C (scientists recommend keeping global warming below 2°C).
Capturing CO2 from power plants or other industrial facilities is straightforward enough: similar to other pollution control technologies, CO2 is separated from the other gases produced during electricity generation or industrial processes. And similar to other pollution control technologies, it must be kept from being emitted into the atmosphere.
Companies that capture carbon can sell it to enhanced oil recovery (EOR). The income can be used to defray the costs of carbon capture thereby creating an additional incentive for power plants and factories to keep CO2 out of the air. In EOR, the CO2 is injected into depleted oil formations, where it mixes with the remaining oil, adds pressure back to the reservoir and enables producers to extract the oil while permanently trapping almost all of the injected CO2 into the reservoir.
So now we’ve gotten rid of the CO2 emissions, provided a payment to companies to capture CO2 and build the pipelines to get the CO2 from the facility to the oil reservoir, but what about the newly produced oil and the emissions that will occur when it is burned? Are we just trading CO2 emissions from power plants and factories for CO2 from burning oil? The answer is definitively: No.
The International Energy Agency (IEA) in 2015 released a report, Storing CO2 through Enhanced Oil Recovery, which included a careful lifecycle analysis and concluded that there is a net CO2 emission reduction of 0.19 metric tons for every barrel of oil produced using CO2 captured at power plants or other industrial facilities (anthropogenic CO2). Most simply, that figures also includes an accounting of the CO2 from using the oil.
To understand what’s behind that number we first need to start with the 0.3 metric tons of CO2 that is injected (and geologically stored) in order to produce a barrel of oil. CO2 EOR results in CO2 stored underground which is kept from contributing to our changing climate. But are we producing more oil in a way that increases net CO2 emissions when the additional oil is combusted e.g., as gasoline? IEA did find that the addition of oil supply through EOR lowers the price of oil driving a small amount of increased consumption – about 20 percent or 2 barrels for every 10 barrels that would otherwise be produced. This means that for every 10 barrels of oil produced with anthropogenic CO2, 8 will displace barrels that would have been produced anyway by more polluting means. IEA concluded that notwithstanding this increase in oil consumption, anthropogenic CO2-EOR would result in significant net CO2 emissions reductions.
The potential scale of the CO2 reductions to be achieved using EOR CCS is massive, even with a net benefit of 0.19 metric tons for every barrel of oil produced using anthropogenic CO2. EOR is now happening mostly using mined natural CO2, so the substitution of anthropogenic CO2 offers a real opportunity. As well, there is potential storage for 140 billion tons of CO2 in oil reservoirs around the world – using anthropogenic CO2 for EOR could therefore reduce emissions up to 88 billion tons. This is more than 40 times the current U.S. power sector emissions.
For a closer look at IEA’s study see CATF’s Fact Sheet: The Emission Reduction Benefits of Carbon Capture Utilization and Storage Using CO2 Enhanced Oil Recovery.