Carbon Capture: a bridging technology too far?

4 pictures

Carbon Capture and Storage slashes CO2 emissions into the atmosphere, but requires an increase in power yield. Image from 2005 IPCC CCS report

View gallery - 4 images

August 7, 2008 Hydrogen Energy International, an initiative of BP and Rio Tinto, has announced plans to construct a hydrogen fuel production facility and power plant in California, with carbon capture and sequestration capabilities. The proposal marks the latest chapter in the saga of carbon capture and storage, a climate change mitigation technology characterized by sporadic and unreliable government support and plagued with accusations that it will worsen the environmental disaster it seeks to address. Yet, despite the negative stigma, CCS has been labeled by the IPCC and the Stern Report as an essential measure in reducing the impact of fossil fuels.

The carbon capture and storage solution involves separating carbon dioxide from fossil fuel at a power plant, either before or after combustion, and injecting it into oil or gas fields, or at least 1000 meters below the surface of the ocean. It sounds almost like cheating, as if we can clean the planet by sweeping the pollution under a geological rug – but a 2005 study by the Intergovernmental Panel on Climate Change asserts that existing CCS technology, if applied to a power plant, could reduce CO2 emissions into the atmosphere by 80-90%. If regulated correctly, geological formations could then hold 99% of the stored CO2 emissions for over 1,000 years.

CCS systems could be built, or retrofitted, fairly easily because the component technologies are very familiar. CO2 capture is already used for natural gas separation in refineries; the US is currently home to 5,800km of CO2 pipeline; and injection of CO2 into geological deposits is a common method of extracting the maximum amount of oil from depleted reserves. The challenge of CCS is turning existing technologies and processes into a worldwide infrastructure in a short enough amount of time to alleviate our pollution levels as we transition to clean energy. The IPCC envisions CCS as a bridging solution, not a silver bullet that allows us to keep using fossil fuels indefinitely. However, if it is to function as a bridging solution, it needs to be applied almost immediately. Though an extended CCS phase will please the power brokers by preserving their infrastructure, it will ultimately pull resources away from developing the new energy sources that CCS is designed to transition into. It is on these grounds that Greenpeace spokesperson Daniel Kessler disagrees with the scheme: "We are against coal carbon sequestration. The reality is that the technologies are going to require billions of dollars of investment. If we go that way, it's going to come at the expense of renewable energy."

The proposed Californian power plant will manufacture hydrogen from petroleum coke and coal, generating up to 400 gross megawatts of base-load low-carbon electricity. The carbon that is produced, some two million tons, will be captured and stored in underground geological formations, and used for enhanced oil recovery in the Elk Hills oil field. The next step for the power plant will be a comprehensive regulatory review process by the California Energy Commission – if approved, it will greenlight the construction of the USA’s first industrial-scale low-carbon power plant with CCS.

The fact that Hydrogen Energy International’s project will be the first such power plant is more a cause of worry than jubilation – it’s a reminder of the trail of canceled CCS projects that showed equal promise. In January of this year, the Department of Energy withdrew funding from FutureGen, a proposed 275-megawatt coal power plant that would use CCS to almost eliminate its CO2 emissions. While the FutureGen Alliance still plans to move forward with the project, the most disappointing aspect of the story is the allegation raised by Illinois senator Dick Durbin that the reason for the DOE’s withdrawal was due to Illinois, not Texas, being chosen as the plant’s location, (the DOE cites ballooning costs as their reason for exiting the agreement). If Durbin is correct, it would seem to indicate that even CCS, an initiative that preserves the fossil fuel status quo, is resigned to the same fate as most other green technologies: forced to navigate an endless obstacle course of ruthless lobbies, erratic government support and pork barrel politics.

“Six Thousand Feet Under”, a 2008 paper on the feasibility of CCS, mentions similar political problems have occurred in the UK, where the government did not support the development of CCS at the Peterhead gas plant, and rejected “a diversity of industry CCS propositions in 2007 which, if built, could decarbonise the supply of 20% of all UK electricity starting from 2012.” The IPCC report claims that CCS can only be a viable option for reducing emissions if governments offer financial incentives for companies to pursue it. If governments adopt a toe-in-the-water approach to such a time sensitive problem, they risk missing the window of opportunity entirely.

However, political uncertainty will hopefully be remedied by a number of extremely promising CCS initiatives that will yield invaluable research within the next few years. The Scottish Centre for Carbon Storage has a map which charts commercially significant CCS sites around the world. Notable examples include the Sleipner plant, located in the North Sea, which has stored one million tonnes of CO2 per year since 1996; the Algerian In Salah plant which stores 1.2 million tonnes of CO2 per year; and the Snohvit gas-field based plant which stores 700,000 tonnes per year. The most promising items on the map are proposals and demonstrations, including the CO2CRC Otway project located in Australia. The demonstration project aims to inject and store 100,000 tonnes of CO2 in a depleted natural gas reservoir, while being monitored by a large team of international scientists.

As momentum for CCS in the government and the private sector builds, it’s important to remember that the IPCC envisions it working only in conjunction with other alternate energy sources. The IPCC report states that “in most scenarios for stabilization of atmospheric greenhouse gas concentrations between 450 and 750 ppmv CO2… CCS contributes 15–55% to the cumulative mitigation effort worldwide until 2100, averaged over a range of baseline scenarios.”

The technology is restricted in its ability to fully combat climate by environmental, technological and economic factors. First, it is uncertain what effects CO2 injection will have on the environment. Ocean storage of CO2 can cause the death of organisms and increased acidity, while leakage from geological storage could present health problems to nearby life. Capturing and transporting CO2 also requires more energy to be produced, increasing the energy needs of a coal plant by 25% and the system costs by up to 91%. CCS systems with storage as mineral carbonates would need 60–180% more energy. Energy, (and CO2), is also expended transporting the CO2 to its destination, and laying new pipelines. The IPCC estimates that incorporating CCS into a pulverized coal plant would put the cost of energy at between 0.06-0.10 US$ per kWh based on 2002 figures, as opposed to the 0.04-0.05 US$ per kWh without capture.

Unfortunately, by the time corporations and governments embrace CCS as a way to appease environmental concerns with minimal change, it's likely that they will already be running too late on the IPCC's schedule. The UK and US have plans to produce functional, industrial-scale CCS plants by 2015-2020, but more skeptical estimates place CCS adoption more at the 2030 mark. It's possible that CCS, brought in as temporary solution to usher in a new age of clean, renewable energy, will go down as a Frankenstein monster that increased the ability of governments and corporations to produce dirty power well beyond their ecological means.

Kyle Sherer

View gallery - 4 images
Show 2 comments

Recommended for you

Latest in Environment

Editors Choice

See the stories that matter in your inbox every morning