The Great Ocean Road, about 200 km southwest of Melbourne, draws millions of tourists to view the spectacular cliffs and limestone stacks known as the Twelve Apostles, carved by relentless Bass Strait waves and winds. But this region is as rich in fossil fuels as it is in scenic beauty, and several commercial gas fields have been opened in the Otway Basin along the continent’s southern margin.
There is also the CRC for Greenhouse Gas Technologies’ (CO2CRC) flagship carbon capture and storage (CCS) trial: the CO2CRC Otway Project – the world’s largest demonstration of its kind.
Since the project started in 2008, the Australian government, US Department of Energy and CRC partners have funded the injection of more than 65,000 tonnes of CO2 into the Otway Basin’s depleted gas fields, without leakage or measurable effect on soil, groundwater or atmosphere.
The project was further boosted by $25 million in Australian government funding in February this year. “The wide-scale deployment of CCS is critical to reduce carbon emissions as quickly and cost-effectively as possible,” says CO2CRC chief executive Tania Constable. “This funding will enable CO2CRC to embark on a new program of research to improve CCS technologies.”
Australia is well-endowed with natural resources. Its known uranium reserves are the world’s largest, and it is rich in natural gas. Traditionally, the most important resource has been coal: Australia has the fourth largest coal reserves globally and is the world’s second biggest coal exporter behind Indonesia. Coal exports – which have grown 5% annually over the past decade – will earn $36 billion in 2014–2015.
Figures like these have led Prime Minister Tony Abbott to declare coal “an essential part of our economic future”. Professor Chris Greig, Director of the University of Queensland’s Energy Initiative, a cohort of research expertise across all energy platforms, anticipates the country will continue to be reliant on fossil fuels, including coal, until at least mid-century. But just how far beyond that depends on how the world – particularly China, one of Australia’s biggest coal customers – addresses future climate change.
In 2014, the US-China emissions deal set China a goal to source 20% of its energy from zero-emissions sources and peak its CO2 emissions by 2030. In August 2014, amid worsening public sentiment over air pollution, the Beijing Municipal Environmental Protection Bureau announced that it would be phasing out coal-fired power in the capital’s six main districts by 2020.
China has been pouring money into the development of renewable energy technologies, spending an estimated US$64 billion on large-scale clean energy projects in 2014 alone. This was five times more than the next biggest spender, according to market analyst Bloomberg New Energy Finance. China is also investing heavily in CCS technologies, with at least 12 projects currently underway.
There are several pathways toward reducing emissions from the electricity sector – from the adoption of nuclear energy and greater uptake of renewable sources and natural gas, to more efficient power plants and modified diesel engines that can burn liquefied coal. CCS, however, is one of the most promising methods for reducing emissions from coal-fired power stations. Capture technologies isolate and pump CO2 underground to be stored in the pores of rocks (see graphic page 29).
Rajendra Pachauri, who until early 2015 was Chair of the Intergovernmental Panel on Climate Change, told the UN 2014 Climate Summit in New York, in September 2014: “With CCS it is entirely possible for fossil fuels to continue to be used on a large scale”.
Dianne Wiley, CO2CRC’s program manager for CCS, says CO2 capture technologies are already available to install. Their deployment is limited by high costs, but there have been strong successes. Wiley points to the commercial scale Boundary Dam Integrated Carbon Capture and Sequestration Demonstration Project in Saskatchewan, Canada – the world’s first large-scale power plant to capture and store its carbon emissions – as a good example of what’s possible with CCS technology. It became operational in October 2014 and, its operators say, is already “exceeding performance expectations”. The CAN$1.3 billion cost of the system should drop by around 30% in subsequent commercial plants, says Brad Page, CEO of the Global CCS Institute.
Greig says that investment decisions in favour of CCS in Australia won’t happen until more work is done to find high-capacity storage basins around the continent that can safely and reliably store CO2 emissions for several decades.
Constable says the recent injection of capital from the Federal Government to the Otway Project will help the CRC take the necessary steps to meet this challenge. She says it will “lower the costs of developing and monitoring CO2 storage sites, enhance regulatory capability and build community confidence in geological storage of CO2 as a safe, permanent option for cutting emissions from fossil fuels”.
Retrofitting CCS technology to existing plants isn’t an option: Greig likens that to “building a brand new garage onto the side of a house that’s falling down – you just don’t do it”. CCS would therefore require investment in new coal-fired power stations.
“A well-conceived energy policy for the electricity generation sector would see ageing, low-efficient plants replaced with high-efficiency ultra-supercritical [coal] plants,” says Greig, adding that these plants have lower emissions simply by virtue of their efficiency and could achieve emissions reductions of 25% compared to existing plants.
How CCS works
The first step of carbon capture and storage (CCS) is capture. It involves separating CO2 from other gases in the exhaust stream from a fossil fuel power plant or some other industrial facility. This can be done with solvents that absorb CO2 or with ceramic and polymer membranes that act as filters. Once isolated, CO2 is compressed into a state in which the difference between liquid and gas can no longer be distinguished. It is then transported via pipeline to a prospective storage site. Here, the CO2 is injected into an underground reservoir, such as a geologic formation or depleted oil field. The CO2 has to enter the rocks without fracturing them, and can then be stored underground for thousands of years.
– Myles Gough