UCC Energy’s John Langley and Keith Clark presented a paper on increasing the efficiency of the conversion of coal to power, thereby reducing the greenhouse gas emission for the same power production through new high-efficiency generation systems.

 

UCC is coal that has had virtually all of the mineral contamination removed from it using a chemical leaching process based on caustic leaching similar to the Bayer process used to refine bauxite into alumina.

 

The use of ultra clean coal in a gas turbine combined-power plant has the potential to reduce greenhouse gas emissions by more than 20% compared to conventional coal based systems.

 

If the program proves successful it will not only have beneficial environmental effects but will also significantly lift the demand for UCC.

 

If UCC is used in gas turbine generation plants to a level where it represented only 2% of the gas to electricity market, it would require the production of 19 million tonnes of UCC every year.

 

Other markets for UCC such as recarburizers for the steel industry and high purity reductants for the smelting of high purity silicon, are smaller but high value and could be accessed with product from a demonstration scale UCC plant. This would allow the possible offset of some of the costs of operating the demonstration plant.

 

An Australian Japanese collaborative research program aimed at utilising Japan’s expertise in coal utilisation and gas turbine development together with Australia’s expertise in the production of UCC was started in 1998 and completed this year.

 

UCC Energy undertook to supply tonnage quantities of UCC from its pilot plant while the Japanese role was the evaluation of the UCC as a direct-combustion gas turbine fuel.

 

Currently the next step in the evaluation of UCC is combustion tests similar to ones already performed but at elevated pressure and firing against turbine blades, in order to assess the corrosion and erosion properties of the UCC.

 

Following success at this stage, UCC should proceed to a small commercial/demonstration scale gas turbine. These last stages will require large tonnages of UCC possibly requiring an initial upgrade of the current pilot plant, but eventually requiring that the UCC production be scaled up to demonstration/commercial scale.

 

This last stage of the development of UCC fuelled gas turbine power generators is extremely costly, and discussions are already underway concerning this development.