Aviva is leading the way with "oxy ready" technology at its Coolimba Power Project, which will allow up to 90% of the future carbon emissions produced by the plant to be captured and stored.
The Coolimba Power Project will operate for at least 30 years from 2011/12, and during its operating life, it is very likely that the project will be subject to commercial constraints on the emission of carbon dioxide. Indeed, it seems likely that some form of carbon emissions trading will be introduced in Australia from about 2011 or 2012, which will impact the Coolimba Power Station, and all other major coal fired power stations in the country.
To minimise the impact of emissions charges on the power station, and as a demonstration of the seriousness with which Aviva takes its environmental obligations, the Coolimba Project will be built from the outset as a coal fired boiler that will be capable of rapid conversion to capture the carbon dioxide produced during the combustion of coal.
The boiler will be constructed as "oxy ready", meaning that the boiler will be capable of being converted from air firing to oxygen firing. This process ('oxy firing') burns coal in the presence of oxygen, not air, producing a high concentration of carbon dioxide in the waste gas stream. This carbon dioxide can be readily cooled and compressed, ready for transport as a liquid to a suitable underground storage location (sequestration).
In this way, about 90% of the carbon dioxide produced by burning coal can be captured and stored, reducing the project emissions to about 90 kg per MWh, about 20% of the emissions currently being achieved by natural gas fired combined cycle generating plants. Oxy firing has not yet been applied on this scale anywhere in the world. However, a 30 MW demonstration project is currently being built in Queensland, and will enter service in 2009. The Coolimba project aims to build on the experiences of this project to become the first commercial scale oxy ready project in Australia.
Converting the boiler to oxy firing is only one step in the process of capturing and sequestering C02. Suitable locations will need to be found for the long term storage of C02. Hence, Aviva will work with the CRC for C02 capture and storage, based in WA at Curtin University, to support the necessary research and development work to allow the C02 to be sequestered immediately after the oxy firing conversion is completed at Coolimba.
Aviva does not propose to oxy fire the project from the outset, and there remains a lot of work to do to identify and secure the sequestration sites which will not be complete by the proposed start date for the project, but the company is committed to making Coolimba the first commerical "carbon capture ready" power station in Western Australia.