Low Emissions Coal Technologies
Coal extraction is one of New South Wales most significant industries. Not only does coal contribute valuable dollars and jobs to the NSW economy, it also provides 90% of the electricity in NSW. Although coal provides most of the energy needed to power NSW industry, business, recreation and general quality of life, this valuable resource is also a carbon-intensive energy option and accounts for a high proportion of NSW total greenhouse gas emissions. The use of coal as a reliable and economically sustainable energy source in NSW, and indeed throughout the world, is not expected to change appreciably over the near to intermediate term. In a future carbon-constrained world, solutions will be required to reduce the greenhouse gas emissions associated with generating electricity from coal.
What are low emissions coal technologies?
Low emissions coal technologies (also sometimes referred to as ‘clean coal technologies’) is the term used to describe technologies designed to enhance the environmental performance of coal used to produce electricity. These technologies aim to significantly reduce greenhouse gas emissions, particularly carbon dioxide (CO2), and their associated environmental impacts, as well as reduce waste from the process in coal extraction, preparation and utilisation.
What is Carbon Capture and Storage (CCS)?
While increasing the combustion efficiency of coal will go someway to reducing greenhouse gas emissions, any significant reductions in carbon dioxide (CO2) emissions from coal fired power stations can only be achieved by capturing CO2 emissions before or after the coal is burnt, and then safely storing it in a secure and permanent manner. This is a process known as carbon capture and storage (CCS).
Carbon dioxide Capture and Storage (also known as CCS) uses those low emission coal technologies to efficiently burn coal and reduce the output of CO2 emissions, but then also separates out the CO2 and captures it before it is vented into the atmosphere. To capture the CO2 , it must be first be separated from other gases that result from combustion or processing. Some gas streams resulting from industrial processes, such as natural-gas purification and ammonia production are very pure to begin with, whilst others may not be. Three major options are available for the capture of carbon dioxide;
- A post-combustion system separates the CO2 from the other flue gases using an organic solvent.
- A pre-combustion system starts by processing the primary fuel with steam and air or oxygen. The resulting carbon monoxide then reacts with steam in a second reactor. This produces hydrogen for making energy or heat as well as CO2,which is separated out and captured.
- Oxy-fuel combustion uses oxygen instead of air to burn the fuel. It results in a flue gas containing mainly water vapour and CO2. The water vapour is removed by cooling and compressing the gas stream. This technology, which is still in its demonstration phase, can capture nearly all the CO2 produced, although the need for additional gas treatment systems to produce the oxygen and to remove pollutants such as sulphur and nitrogen oxides lowers the CO2 avoided to about 90%.
The CO2 is then compressed into a supercritical state (so it performs like a liquid) and is easier to transport by way of pipeline, road or sea transport to an injection well, and then injected into well understood secure underground, long-term gas storage reservoirs such as depleted oil and gas fields, unmineable coal seams and deep saline formations, that are monitored long after the closure of the site. Alternative storage methods and options are also being considered such as mineral carbonation and bio algal sequestration.
The major application of CCS is to reduce CO2 emissions from fossil fuel power plants, principally coal and natural gas. However, CCS can also be applied to CO2 intensive industries such as cement, iron and steel, petrochemicals, and oil and gas processing. The International Energy Agency estimates that by 2050, CCS from power generation, industry and fuel transformation could contribute up to 19% of the effort to reduce global CO2 emissions (or 9.4 Gigatonnes of CO2 per year by 2050). Therefore, this group of technologies is expected to play a significant role in dealing with the complex and challenging problem of providing reliable and economically and environmentally sustainable electricity production in a future carbon-constrained world.
Why do we need these technologies?
Coal contributes about 27% of global primary energy demand, second only to oil (34%) and is used to produce 42% of the world’s electricity. Coal is also the key requirement for two other building blocks of modern society – the production of steel and cement.
Burning coal to produce electricity is recognised as a major contributor to greenhouse gas emissions. Ninety per cent of electricity used in NSW is generated from coal-fired power stations. NSW’s coal fired power stations accounted for about 63 million tonnes of CO2 emissions in 2008. This form of power generation emits 38 per cent of NSW total greenhouse gas emissions. This figure is likely to rise as the demand for electricity grows.
Whilst there have been small scale trials of various CCS technologies and four commercial scale CCS gas production facilities in operation, there is no fully integrated industrial-scale CCS coal-fired power station built to date (i.e. one which demonstrates at a commercial scale the various stages from combustion, separation, transportation and storing of CO2). The world needs to know now if CCS is to reach its potential.
What is the NSW State Government doing?
NSW is driving major change in the energy sector, stimulating the deployment of new technologies and lower carbon fuels to ensure our future power supply is cleaner, affordable and reliable. The NSW Government's Greenhouse Plan and State Plan set a world first greenhouse gas target of a 60% cut in greenhouse gas emissions by 2050. Employing low emission coal technologies in NSW will be a key factor in achieving this target.
The NSW Government is active in reducing greenhouse gas emissions through a number of initiatives which include:
- Clean Coal Council
- Clean Coal Fund
- Clean Coal Fund Research Projects
- NSW CCS Demonstration Project
- NSW Storage Capacity Project
- 2010 NSW Low Emissions Coal Technologies Summit
- 2008 NSW Clean Coal Summit
Amongst these initiatives was the establishment of the NSW Clean Coal Council and the $100 million Clean Coal Fund. Through the Clean Coal Fund, the NSW Government is supporting a total of ten projects through a comprehensive $13 million Research and Development program to drive technological developments in low emissions coal technologies that cover the full breadth of coal application in NSW from:
- Fugitive methane emissions from coal mines
- Coal combustion and electricity generation efficiency
- Post-combustion capture of carbon dioxide (CO2)
- Storage of captured carbon dioxide (CO2)
- Public consultation and community awareness
Working in collaboration with others
Through the Clean Coal Fund, the NSW Government is providing financial support and partnering with such project proponents as:
- Centennial Coal
- Commonwealth Scientific and Industrial Research Organisation (CSIRO)
- Priority Research Centre for Energy, University of Newcastle
- Research Institute for Social Inclusion and Well-being, University of Newcastle
- UCC Energy Pty Ltd
More information on these projects can be found under NSW Clean Coal Fund Research Projects.
The NSW Government is a member of the Carbon Storage Task Force which was established by the Australian Government under the National Low Emissions Coal Initiative in October 2008, to develop the National Carbon Mapping and Infrastructure Plan. The National Carbon Mapping and Infrastructure plan is Australia’s roadmap in prioritising the development of suitable storage sites and the necessary pipeline infrastructure. Several basins in NSW were listed as a priority 1 for pre-competitive exploration. This is supported by the work program set out in the NSW Storage Capacity Project.
A copy of the report can be obtained from here (www.ret.gov.au).
The NSW Government is a formal member of the Global Carbon Capture and Storage Institute (Global CCS Institute) which is a bold new initiative aimed at accelerating the worldwide commercial deployment of CCS at scale. Announced by the Australian government in September 2008, the Global CCS Institute was formally launched in April 2009. Recognising the important contribution CCS can make in ameliorating climate change, the Australian government has committed $100 million in annual funding for the Global CCS Institute. The Institute will play a pivotal role in facilitating the development and deployment of safe, economic and environmentally sustainable commercial scale CCS projects. The Institute currently has 226 members. The cross-cutting membership comprises national governments, industries, research organisations and other interested stakeholders.
More information: www.globalccsinstitute.com.
I&I NSW is also a participant in the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), one of the world’s leading collaborative research organisations focused on carbon dioxide capture and storage technologies. This CRC has more than 100 scientists working to develop safe and economic geosequestration technologies. The CO2CRC is also conducting the Otway Project which is Australia’s first demonstration of deep geological storage or geosequestration of carbon dioxide (CO2), the most common greenhouse gas (www.co2crc.com.au). The project provides technical information on geosequestration processes (www.co2crc.com.au), technologies and monitoring and verification (www.co2crc.com.au) regimes that will help inform public policy and industry decision-makers while also providing assurance to the community. The CO2CRC is a joint venture of industry, government, universities and research bodies from Australia and overseas. The CO2CRC has also developed a CCS Atlas for New South Wales Australia, The Atlas provides a variety of maps and diagrams that summarises a range of geological, topographic, industrial, cultural and other features which influence the extent to which CCS may be used in NSW in the future as a greenhouse gas mitigation option.
More Information: www.co2crc.com.au
Further information
Email ccs.info@industry.nsw.gov.au
The Intergovernmental Panel on Climate Chance (IPCC) Special Report on Carbon Dioxide Capture and Storage provides invaluable information for researchers in environmental science, geology, engineering and the oil and gas sector, policymakers in governments and environmental organizations, and scientists and engineers in industry.
The International Energy Agency (IEA) is an intergovernmental organisation that conducts a broad programme of energy research, data compilation, publications and public dissemination on the latest energy policy analysis and recommendations on good practices.
The IEA Greenhouse Gas R&D Programme (IEAGHG) is an international collaborative research programme established in 1991 as an Implementing Agreement under the International Energy Agency (IEA). IEAGHG studies and evaluates technologies that can reduce greenhouse gas emissions derived from the use of fossil fuels. The Programme aims to provide its members with definitive information on the role that technology can take in reducing greenhouse gas emissions.
The Carbon Sequestration Leadership Forum (CSLF) is a Ministerial-level international climate change initiative that is focused on the development of improved cost-effective technologies for the separation and capture of carbon dioxide (CO2) for its transport and long-term safe storage. The mission of the CSLF is to facilitate the development and deployment of such technologies via collaborative efforts that address key technical, economic, and environmental obstacles. The CSLF will also promote awareness and champion legal, regulatory, financial, and institutional environments conducive to such technologies.