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Schools in Science

Alan Chaffee

BSc(Hons), Ph D(Melb)

Room: 221N, Building 23N, Clayton
Phone: +61 3 9905 4626
Fax: +61 3 9905 4597

Current Projects

Current projects are focussed on the chemistry of lignite-water interactions. As mined, Victorian lignite contains approximately 60% water – i.e. more water than carbonaceous matter. In current practice, this water is removed evaporatively leading to large inefficiencies in power generation. Together with the Department of Chemical Engineering, we are working on the development of a new drying process known as Mechanical Thermal Expression (MTE). This process removes the water as a liquid, such that the heat of evaporation is saved. The following projects have the support of the CRC for Clean Power from Lignite.

Lignite Dewatering

This project aims to establish relationships between MTE process conditions and the physico-chemical properties of lignite. Properties being studied include surface area, pore size distribution, chemical composition, H-bonding (by DRIFT-IR) and thermal stability (TGA). This information will assist in optimising the efficiency of the MTE process.

Characterisation of Organic and Inorganic Components in Product Water from Lignite Dewatering

It is important to develop an understanding of the composition and concentration of both organic and inorganic components that are removed from lignite by the MTE process and remain in the product water. This information will used to assist in the development of strategies to minimise any potential environmental impacts. This project makes extensive use of analytical techniques such as GC-MS and ICP-AES.

Maceral Separation

Macerals are the discrete remains of wood, leaves, resins, etc that can be visually identified under the microscope (or are sometimes large enough to be hand-picked from the lignite seam). Macerals in lignite are analogous to the mineral phases of inorganic rocks. Centrifugation, using a carrier liquid of fixed density, is being investigated as a means of conveniently separating individual macerals from the coal matrix. The organic structure of a particular maceral type is clearly much less complex than lignite as a whole. Hence, the isolation of macerals will assist in the elucidation of lignite structure and of lignite-water interactions.

Maceral-Water Interactions: Theoretical and Experimental Investigations

The experimental part of this project is using state-of-the-art gravimetric and volumetric adsorption methods to measure heat of adsorption of water as a function of loading. The theoretical part of this project involves the development of macromolecular models which reflect maceral structure. Molecular dynamics methods will be used to simulate water adsorption experiments, which can then be compared with experimental data to assess model validity. Infrared (DRIFT) and solid state NMR techniques will be used as complimentary techniques to assist in the elucidation of maceral structure.

Research Interests

Other research interests cover the general field of Energy and Fuels. Specific areas include:
  • heterogeneous catalysis - especially in relation to the production of alternative fuels, the interconversion between fuels and fuel processing
  • organic geochemistry - the molecular transformations involved in the conversion of biopolymers into geopolymers
  • materials development and characterisation - particularly in the context of the development of tailored adsorbents and catalysts

Projects in these areas above are under development.