Clean Coal Technologies in Australia
 Australia has been at the forefront of research
and development aimed at improving the efficiency
of power generation (using less coal to generate
a given amount of energy), development
of new ways of using coal, such as gasification, and technologies to limit/prevent emissions to the atmosphere.
Listed below are some examples of the kinds of clean coal technologies (CCTs) currently in operation or under development in Australia, including projects and developments relating to brown coal (Lignite):
Supercritical Conventional Coal Plants
Thermal efficiency is a measure of how much useful energy can be extracted from a given amount of coal. Thermal efficiency in coal-fired power generation has increased from about 5 per cent in 1900 to an average of 38 per cent for modern pulverised fuel (pf) power plants. Every 1 per cent increase in thermal efficiency results in a 2-3 per cent decrease carbon dioxide emissions.
 Advanced modern plants use specially developed alloy steels which enable the use of supercritical and ultra supercritical steam to achieve efficiencies of 45 per cent and above. As the technology advances, efficiencies of 55 per cent and above should be achievable in the near future.
The first power station in Australia to employ supercritical technology to reduce coal consumption and reduce greenhouse gas emissions was CS Energy/InterGen’s Callide Power Station in Queensland (pictured), commissioned in 2001.
This was followed by InterGen’s $1.5 billion Millmerran Coal Thermal Power Plant, also located in Queensland, which was officially opened by Premier Peter Beattie on 31 January 2003. The 840MW power station is the largest "greenfield" private investment in electricity generation in Australia (as opposed to purchasing an existing facility from a government utility).
In July 2003 Tarong Energy's 450MW Tarong North Power Station was also completed, at an estimated cost of $650 million. This new supercritical plant is more efficient than the older 1400MW Tarong power plant because of the much higher steam pressures (25 megapascals instead of 17MPa) and higher temperatures (566 degrees C compared with 538 degrees C ).
CS Energy's Kogan Creek Power Project comprises a single 750MW supercritical unit and a new open-cut mine on the adjcent Kogan Creek coal deposit, located near Chinchilla in sout-east Queensland. This $1.1 billion project was given final approval to proceed to construction in May 2004, and is scheduled to come on-line towards the end of 2007.
Coal Gasification
Advanced power generation systems based on gasification of coal have the potential to be both cheaper and cleaner than conventional technology. When coal is brought into contact with steam and oxygen, thermochemical reactions produce a fuel gas, mainly carbon monoxide and hydrogen, which, when combusted can be used to power gas turbines.
Integrated Coal Gasification Combined Cycle (IGCC) power generating systems give increased efficiencies by using waste heat from the product gas to produce steam to drive a steam turbine, in addition to a gas turbine. Gasification systems can achieve efficiencies of greater than 50 per cent, produce less solid waste, lower emissions of pollutants like sulphur dioxide and nitrous oxide. and lower carbon dioxide emissions.
 The suitability of Australian coals for gasification has been extensively researched over recent years, with work centred on an advanced gasification facility at CSIRO’s Pinjarra Hills laboratories in Queensland. (Pictured: Entrained-flow reactor at the facility.)
The research program has been a collaborative effort involving the former Cooperative Research Centre for Black Coal Utilisation, CSIRO Division of Energy Technology and the Australian Coal Association Research Program.
The gasifier is one of very few in its class of high pressure and temperature equipment. It is unique in the extent of its capabilities for simulating reaction conditions in commercial entrained-flow gasifiers.
Australian researchers are also investigating the potential for underground gasification of coal which may also involve capture and sequestration of carbon dioxide to virtually eliminate atmospheric greenhouse gas emissions.
For further information see: http://www.cat.csiro.au/3_4.htm
Integrated Gasification Combined Cycle (IGCC)
ZeroGen would be the world's first demonstration plant that integrated a coal gasification power plant with the capture and storage of carbon dioxide (CO2) emissions to generate low emission base-load electricity. The project, which is based on technology from Shell, would convert coal to a synthesis gas removing CO2 and other gases to produce a fuel rich in hydrogen used to generate power in an integrated gasification combined-cycle (IGCC) power plant.
Click on image for more details
The gasification plant will be located at Stanwell Energy Park , just west of Rockhampton in central Queensland . CO2 will be captured at the site and transported by pipeline for safe storage in deep underground saline aquifers in the Denison trough, approximately 220 kilometres west near Emerald.
ZeroGen is currently undertaking a range of studies in order to obtain the necessary regulatory approvals and funding. As part of the feasibility study test drilling of geological sites has also commenced. The test drilling program is a necessary scientific procedure to confirm the geology of the area and its ability to safely and securely store CO2. It has also been designed to minimise impacts on the community with agreements for the test drilling negotiated with landholders and with traditional owners of the area.
For further information see:
http://www.zerogen.com.au/home
http://www.ccsd.biz/factsheets/igcc.cfm
Post Combustion Capture ( PCC )
CSIRO's Energy Transformed Flagship has committed just over $A1 million in 2005-06 to establish a Post-Combustion Capture ( PCC ) program.
This research program, which is being undertaken in cooperation with industry, takes an entirely new approach to way that we view the reduction of greenhouse gas (GHG)  emissions. It is planned to continue for the next five years.
The 2005-06 program is the first stage in a proposed PCC demonstration project which will be complemented by research focussing on developing new component technologies that includes:
- materials and technology integration
- novel membranes
- pilot scale trials at power stations using the CSIRO National PCC Facility - pictured >
- sorbents.
Research outcomes are expected to deliver:
- identification of optimum implementation pathways for PCC and competing technologies for CO2 utilisation in enhanced coal bed methane recovery and storage in coal strata
- materials science and molecular engineering, particularly to develop high efficiency sorbents
- process optimisation and novel integration options
- technologies for gas conditioning and separation for post combustion retro-fit, with optimum host plant energy integration.
Currently, Australian infrastructure investment in pulverised fuel (PF) fired power stations is over $A40 billion. These facilities have a forecast operational life of 50 years and by 2020, 38 Gigawatts of old PF capacity will remain in use. Step reductions in CO2 emissions, by economical capture from PF stations, is essential in order to avoid massive stranded (unusable) assets.
The Energy Transformed Flagship believes PCC can achieve this outcome, given the level of commitment it is making to research and development activities. The overall impact of achieving the goal of cost-effective capture for existing plants is enormous and the benefit will be increased by application to new future installations.
Click on image below for a short video demonstration of PCC >
For further information see:http://www.csiro.au/science/ps12u.html
Oxy–Fuel Combustion
Eleven Australian and Japanese organisations have formed a consortium to develop a reference design for a demonstration oxy-fuel combustion plant, with CO2 capture in geological storage, based on CS Energy's Callide A power station in Queensland .
 This project will be the first of its kind in Australia and it will be a very significant step forward in Australia 's greenhouse response, and a clean coal future. Oxy-fuel combustion is one of the priority technologies identified in the COAL21 “Plan of Action for Australia ” as being of most relevance to Australia because of its potential applicability as a retrofit option for Australia 's existing fleet of coal-fired power stations.
The oxy-fuel combustion process involves feeding a modified power station boiler with pure oxygen rather than air, and recycling a proportion of the flue gases through the combustion chamber. This has the effect of significantly raising the concentration of CO2 in the flue gases, making it easier to capture and store this greenhouse gas.
Pictured: Inside the Callide A furnace during the condition assessment October 2006.
The oxy-fuel project will have two stages:
Stage 1 – Detailed engineering feasibility study on the technical requirements and costs to convert an existing pulverised coal fired boiler (Callide A's 30 megawatt unit) to oxy-firing (approximately $3 million).
Stage 2 – Pending the outcome of Stage 1, establishment of a demonstration plant capable of producing up to 150,000 tonnes per year of CO2 for geological storage over a test period of 3 to 4 years.
Oxy-fuel technology is important to power and coal companies at an international level because of:
• the potential for a medium to long-term lower cost and lower technology risk option for achieving near zero emissions from coal-based electricity generation.
• the potential to retrofit this technology to standard pulverised coal fired boilers.
• the prospect of applying the technology to new coal-fired plant with significant reductions in the capital and operating cost of flue gas cleaning equipment, such as that used to reduce the concentration of oxides of nitrogen (deNOx plant).
For further information see: http://www.csenergy.com.au/research_and_development/oxy_fuel.asp
http://www.ccsd.biz/factsheets/oxyfuel.cfm
Lignite Dewatering & Drying
A number of lignite utilization technologies are currently under development in Australia . One example includes initial gasification of the coal followed by liquefaction to produce ultra clean fuel products with the option to generate power as a by product.
Others include use of binderless briquettes or integrated drying gasification combined cycle (IDGCC) which dries the coal and enhances syngas intensity for power generation resulting in increase efficiency and reduced greenhouse gas emissions.
 The most advanced dewatering, drying and gasification projects currently under development in Australia include those by Monash Energy, HRL Technology (2006 – gasification plant), and Hazelwood Power Station (2006 – drying technique).
Pictured: An artists impression of the proposed Hazelwood development (International Power) in Victoria.
In February 2006, the Australian Minister for the Environment and Heritage, Senator Ian Campbell, announced $2.2 million funding for a project to help the development of a new technology that could significantly reduce greenhouse gas emissions from brown coal.
The Mechanical Thermal Expression (MTE) pilot plant will be constructed at Loy Yang power generating plant in Victoria . The MTE technology is based on the concept of pre drying the coal before its use as a fuel in boilers. This project is a joint venture between the Australian Government, the Victorian Government and industry. The funding for the project has been provided under the Australian Government's Greenhouse Gas Abatement Program.
For further information see:
http://www.monashenergy.com.au/
http://www.hrlt.com.au/
http://www.hazelwoodpower.com.au/
Ultra Clean Coal as a Gas Turbine Fuel
An Ultra Clean Coal (UCC) technology and process to produce an ultra low ash solid fuel for direct firing in gas turbines is currently being piloted in Australia.
The UCC technology and process is being developed by UCC Energy Pty Limited, a wholly owned R&D subsidiary of White Mining Limited, in co-operation with the CSIRO (Commonwealth Scientific and Industrial Research Organisation) and is supported by both the Federal and State Governments.
 The patented technology is well developed and has many environmental advantages including greenhouse gas (GHG) reduction, minimal ash disposal and potentially cheaper electricity production.
Pictured: General view of the UCC pilot plant, Cessnock NSW.
By definition, ultra clean coals are coals with less than 1% ash. The CSIRO/Whites UCC process is producing a new clean solid fuel with ash levels between 0.1% and 0.2%. The UCC process uses alkali/acid digestion to dissolve the minerals out of the coal under moderate temperature and pressure conditions, without the loss of coal properties.
UCC, although based on coal, is not a substitute for conventional coal in conventional power generating systems; its major application is in areas where conventional coal cannot be used. It is an alternative for heavy fuel oil and gas. UCC is cost competitive with these fuels on an equal energy basis.
When UCC is directly fired into a gas turbine, it is estimated that thermal efficiency is increased from around 38% for a conventional coal fired power station to approximately 53% with direct injection of UCC into a gas turbine with combined cycle. In addition a UCC fired gas turbine combined cycle power plant is more amenable to locating close to the electricity users than is the case for conventional coal fired generators, and this opens the possibility of reaching overall energy conversion efficiencies of close to 60%.
With the increase in thermal efficiency there is a very significant reduction in GHG emissions at the power station, for the same amount of electricity generated. Also, life cycle (from mining to electrical power to the customer) GHG reductions of more than 20% are likely to be achieved compared to the conventional coal case. These benefits in emission reduction resulting from UCC are dependent on it being used in advanced combined cycle power-generating systems, not suitable for conventional coal feeds, to obtain the maximum possible thermal efficiency.
The UCC process is suited to most black coals and is therefore of strategic importance to developing countries with indigenous coal supplies, but limited in other energy resources. Additionally the process will also be of interest to other major coal producing countries.
Although the major application of the UCC product is as a fuel, it can also be used as a clean carbon source for metallurgical processes; for instance, in carbon anodes for aluminium production. Mineral by-products from the process may also have industrial application, though little work has been done to date in this area.
For further information see: http://www.uccenergy.com.au/
Other
See: Methane Capture and Use - Australian Examples
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