Dr Karen Steel

Senior Lecturer

School of Chemical Engineering
Faculty of Engineering, Architecture and Information Technology
karen.steel@uq.edu.au
+61 7 336 53977

Overview

Dr Steel’s research supports both the power and metallurgical sectors and is underpinned by a fundamental understanding of both coal microstructure and solution equilibria

1992 - 1995. B.E. (Hons), Bachelor of Engineering (Chemical). The University of Melbourne.

1996 - 1999. Ph.D. (Engineering), Department of Chemical Engineering, The University of Melbourne.

2000. Loughborough University, Research Fellow for Prof John Patrick in the Carbon Research Group.

2000 – 2003. The University of Nottingham, Research Fellow for Prof John Patrick and Prof Colin Snape in the Nottingham Fuel and Energy Centre.

2003 - 2008. The University of Nottingham, Lecturer in the School of Chemical and Environmental Engineering.

2009. The University of Queensland, Lecturer in the Division of Chemical Engineering, School of Engineeering.

Research:

Dr Steel’s research supports both the power and metallurgical sectors and is underpinned by a fundamental understanding of both coal microstructure and solution equilibria.

Current themes:

Metallurgical coal carbonisation (coking)

I am pioneering the use of high temperature oscillatory shear rheometry to characterise the microstructure of coal as it transforms into coke. So far the results have enabled me to understand the underlying mechanisms behind a process problem known as high oven wall pressure, which has remained elusive for decades. The research has been ongoing since 2003 and has been largely supported by BHP Billiton. We are now in a position to use the knowledge gained to develop new tools/devices to both predict coking behaviour and also control it through the use of additives. This research has huge potential to maintain/extend the export value of Australia’s coking coals.

Development of a process for the treatment of Spent pot-lining (SPL)

SPL is a waste from the aluminium industry (Al smelters). It is the spent carbon cathode lining and contains leachable fluoride and cyanide. Currently there is no commercially viable process for its treatment and yet environmental agencies want to prohibit the industry from stockpiling/landfilling it. I have been working on a process that looks at extracting the fluoride and converting it to aluminium fluoride which is needed by the industry and therefore helps the economics. The project is in collaboration with Fluorsid SpA who are part of the process development.

Sequestration of power station CO2 as stable mineral carbonates

Fossil Fuels will remain the world’s primary energy resource for many years to come, therefore technologies for the sequestration of CO2 are of unparalleled importance. Mineral carbonates are known to be stable for millions of years and so conversion of CO2 to carbonate could present a worthwhile solution. Whether the counter ion for carbonate comes from salts or oxides there is a major technological barrier to conversion which is preventing the development of a commercially viable process. This barrier is associated with the difference in pH between carbonate ion formation and mineral carbonate precipitation. Current efforts are examining a novel concept for overcoming this barrier. Given that Mg-silicates can also contain Ni the process could be aligned with the current hydrometallurgical process for Ni recovery. This research has been funded by Sirius Exploration plc.

Development of a process for the production of ultra-clean coal

I have developed a process which reduces the mineral matter content of coal down to 0.1 wt% which makes it possible to burn the coal directly in a gas turbine and therefore makes coal comparable to natural gas. The reagents used to extract the minerals are recycled and the process also selectively separates pure silica as a co-product. The UCC could also supplement petcoke used for the production of carbon anodes in the aluminium smelting industry. Current efforts are focused on reducing the energy requirements of the process, which is the main barrier to commercialisation.

Chemical stimulation of coal seams

Methane is a ‘cleaner’ fuel than coal because it can be burned in high efficiency combined cycles. Coal deposits in eastern Australia have been found to hold enormous amounts of adsorbed methane (known as coal seam gas or coalbed methane). This has given rise to an extremely fast growing industry whereby the methane can be potentially exported as LNG. Gas productivity depends on the permeability of the coal seam. There are currently methods for increasing permeability based on the work done for oil recovery. However, coal has very different properties to sandstone rock. It is a giant macromolecular network capable of swelling and contracting and contains various amounts of mineral matter. These properties could be exploited for developing improved methods for increasing permeability. This field of research in coal science is yet to be fully realised.

Teaching and Learning:

I teach CHEE2002 Process systems analysis which utilises my interest in process development. It looks at unit operations & processes in process engineering & their analysis in terms of degrees of freedom & solvability. Computer-aided flowsheeting tools for process analysis & application to economic & environmental impacts. Techniques for decomposition of large, complex systems to smaller problems.

Projects:

  • 2011-2013, ‘New techniques for predicting and controlling coking behaviour,’ BHP Billiton direct industry funding, $320,000

  • 2010-2013, ‘Use of rheometry to understand structure development during coking – Implications for controlling and predicting coke strength indices,’ PhD scholarship, BHP Billiton direct industry funding,’ $171,000

  • 2010, ‘Sequestration of CO2 as solid carbonate/bicarbonate during solution mining of halites,’ Sirius Exploration plc direct industry funding, $195,526.

  • 2010-2013, ‘Development of a novel process for recovering fluoride from spent pot-lining as AlF2(OH) using industrial waste solutions,’ ARC Linkage LP100100165 with Fluorsid SpA co-sponsor, $110,007.

  • 2010, ‘Coal microstructure characterisation for advanced coal technologies,’ Major Equipment and Infrastructure (MEI) Grant with Joan Esterle, Suzanne Golding, Victor Rudolph, Paul Massarotto, Tim Nicholson, $393,641.

  • 2009, ‘Novel Chemical Stimulation possibilities for improving coal seam gas productivity: Literature Review,’ Consultancy work for Santos Ltd, $15,007.

Research Interests

  • High-temperature rheometry of coal during pyrolysis/carbonisation
    High-temperature oscillatory shear rheometry is being used to provide a unique fundamental understanding of the microstructural changes taking place during coal pyrolysis/carbonisation. So far it has helped to understand the mechanisms responsible for the build-up of pressure in coke ovens, a problem that has remained elusive to coke manufacturers since coke was first made in slot-type ovens. As such, the technique is expected to reveal many improved methods for making coke as well as improved models for predicting pressure. It may also reveal the fundamental mechanisms behind coke quality. The approaches taken may also have application in the fields of coal gasification or petcoke production, or in other industries, particularly where the curing of a foam occurs.
  • Treatment of Spent pot-lining (SPL)
    A chemical leaching process for the treatment of spent pot-lining (a hazardous waste currently going to landfill) has been developed. The process uses Al3+ and recovers fluoride as AlF2OH which can be converted to AlF3 for sale back to smelters. Graphite is also recovered. Low temperatures and pressures, as well as the use of waste solutions as the source of Al3+, help to make the process sustainable. Current efforts are focused on the AlF2OH crystallisation step, where particle size and purity must be optimised.
  • Production of Ultra-clean Coal (UCC)
    A chemical leaching process for the production of UCC has been developed, whereby the mineral level in coal is reduced to below 0.1 wt%, chemical reagents are recycled, and a pure silica co-product is generated. The main application of UCC is direct firing in gas turbines, which would enable coal to be burned in high efficiency cycles such as the natural gas combined cycle (NGCC). The UCC could also supplement petcoke used for the production of carbon anodes in the aluminium smelting industry. Current efforts are focused on reducing the energy requirements of the process, which is the main barrier to commercialisation.
  • Conversion of CO2 into stable mineral carbonates
    Fossil Fuels will remain the world�s primary energy resource for many years to come, therefore technologies for the sequestration of CO2 are of unparalleled importance. Mineral carbonates are known to be stable for millions of years and so conversion of CO2 to carbonate could present a worthwhile solution. Whether the counter ion for carbonate comes from salts or oxides there is a major technological barrier to conversion which is preventing the development of a commercially viable process. This barrier is associated with the difference in pH between carbonate ion formation and mineral carbonate precipitation. Current efforts are examining a novel concept for overcoming this barrier.
  • Novel stimulation methods for enhanced methane recovery from coal seams
    Methane is a �cleaner� fuel than coal because it can be burned in high efficiency combined cycles. Coal deposits in eastern Australia have been found to hold enormous amounts of adsorbed methane (known as coal seam gas or coalbed methane). This has given rise to an extremely fast growing industry whereby the methane can be potentially exported as LNG. Gas productivity depends on the permeability of the coal seam. There are currently methods for increasing permeability based on the work done for oil recovery. However, coal has very different properties to sandstone rock. It is a giant macromolecular network capable of swelling and contracting and contains various amounts of mineral matter. These properties could be exploited for developing improved methods for increasing permeability. This field of research in coal science is yet to be fully realised.

Qualifications

  • Bachelor of Engineering, University of Melbourne
  • Doctor of Philosophy in Chemical Engineering, University of Melbourne

Publications

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Supervision

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Publications

Journal Article

Conference Publication

Grants (Administered at UQ)

PhD and MPhil Supervision

Current Supervision

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Principal Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

    Other advisors:

  • Doctor Philosophy — Associate Advisor

  • Doctor Philosophy — Associate Advisor

Completed Supervision

Possible Research Projects

Note for students: The possible research projects listed on this page may not be comprehensive or up to date. Always feel free to contact the staff for more information, and also with your own research ideas.