Review of New Methodologies and Techniques in Organic Petrology
Dr. Lila W. Gurba
University of New South Wales
Sydney, NSW 2052
A working group on “New Methodologies and Techniques in Organic Petrology” was established within Commission I at the 52nd ICCP meeting in Rio de Janeiro, August 2000. The Working Group was set up to review new methods and techniques that may be of assistance in advancing the science of coal petrology, to familiarise ICCP members with the principles and operation of these techniques, and to indicate to members the application of advanced techniques in coal petrology studies.
The main objective of the Working Group is to provide an update on novel and new methods and techniques that can be applied to Coal and Organic Petrology, including the elemental and organic chemistry of coal macerals, the nature of coal minerals, maturation studies, coal-combustion problems and environmental issues.
- As the first action of the Working Group, presentations were given at the 2000 meeting in Rio de Janeiro on confocal laser scanning fluorescence microscopy by Lavern Stasiuk and fluorescence alteration of multiple macerals (FAMM) by Walter Pickel.
- For the 2001 meeting in Copenhagen a series of presentations were given on topics related to many aspects of organic matter/mineral matter interactions in coal by Petra David (image analysis), Miryam Glikson (TEM) and Colin Ward (XRD).
- The first version of the White Paper, with a description of several novel methods and techniques was presented at the 53rd ICCP meeting in Copenhagen, Denmark, August 2001. The White Paper is dedicated to the memory of Marlies Teichmüller and Alex Cameron, and includes extended abstracts of the presentations given by invited speakers in the Rio and Copenhagen meetings. The White Paper contains the following contribution:
·Pickel, W., Wilkins, R., Buckingham, C., Faiz, M., Kurusingal, J., Russel., N. and Sherwood, N.: Laser Microscopy – FAMM.
·Stasiuk, L.: Confocal laser scanning fluorescence microscopy – summary.
·David, P., Veld, H., Reimer, K. and Raab, C.: Investigation on the organic/mineral matter association and distribution in coal using Colour Image Analysis.
·Glikson, M: Transmission Electron Microscopy (tem), as a tool in characterising organic matter further to organic petrology.
·Ward, C. R.: Quantitative mineralogical analysis of coal using advanced x-ray diffraction techniques.
·Mastalerz, M.: Application of reflectance micro-Fourier Transform infrared (FTIR) analysis to the study of coal macerals.
·Radlinski, A. P.: Applications of Small Angle Neutron Scattering and Small Angle X-ray Scattering to Organic Petrology.
- The White Paper gives the opportunity to publicize the research and gives information about recent international progress in individual research fields A copy of the White Paper is available from the ICCP web-site. The White Paper is open to further contributions. The next update of the White Paper will be prepared following the 61st meeting in Gramado, Brazil.
- In 2003, at the meeting of the 55th ICCP meeting in Utrecht, Netherland, a presentation was given on A new optical and/or image based technique for characterisation of coal/biomass blends before and after milling. The presentation was prepared by Helen Beath and Graham O’Brien from CSIRO, Australia, and presented by the Convenor of the Working Group.
- In 2005 the Convener made a presentation about a new technique for Coal and Mineral Matter Characterisation - QEMSCANTM, developed by CSIRO and Intellection (Australia), in collaboration with the CRC (Cooperative Research Centre) for Coal in Sustainable Development.
QEMSCAN is a methodology whereby coal characteristics such as mineralogy, particle size distribution and mineral association can be measured automatically using a Scanning Electron Microscope (SEM) with a combination of BSE and EDS x-rays to identify, quantify and characterise materials.
The advantages of this new technique as well as details concerning the sample preparation, calibration and measurement parameters were discussed. These include: number and size range of particles to be measured, magnification of the run, spatial and chemical resolution desired, and geometric arrangement of the frames to be scanned. This technique also allows to select which type of measurement mode is required, which includes: point scan, area scan, line scan or frame scan. Multiple modes of measurement can be scheduled within the same run.
This system automatically delineates particles from the mounting media, and then scans each particle found according to the measurement protocols requested. The most common mode used in coal applications is Particle Mineralogical Analysis (or PMA) mode, where the beam scans across each particle and builds up a map of the minerals present.
In the coal industry QEMSCANTM has application in the following areas:
·Coal exploration for seam correlation and coal characterisation for identification of utilisation options;
·Coal preparation for determining efficiency of washery plants and selective mineral removal;
·Characterisation of coal utilisation by-products with respect to waste management, leaching behaviour and utilisation;
·The behaviour of coal and mineral during combustion in advanced power generation technologies such as supercritical and ultra-supercritical pf combustion, FBC and IGCC;
·Coke production and the behaviour of coke in the blast furnace;
·The behaviour of coal and mineral matter during gasification;
·Characterisation of particulate emissions arising from coal production and utilisation.
- In 2006, at the 59th meeting in Victoria, on behalf of the Convenor, Dr Zhongsheng Li presented a talk on the new advances on Electron Microprobe Analysis and Micro-FTIR of macerals and their applications in coal utilization.
Variations in the elemental composition of macerals in coals over a wide range of coal ranks, using light-element electron microprobe techniques, to establish the coalification tracks of key macerals in a single coal-bearing interval from sub-bituminous through bituminous coal to anthracite have been studied and presented. Attenuated total reflectance micro-Fourier transform infrared (ATR-FTIR) spectrometry has been used to characterise coal macerals, in particular telocollinite, changes in the aromatic and aliphatic functional groups, over a wide rank range in coals. Inorganic elements were found in electron microprobe studies of coal macerals, especially vitrinite macerals, without any visible minerals or mineral inclusions in the macerals concerned.
Detailed mapping of the concentration of these elements in macerals of several low-rank coals reveals that a majority of inorganic elements occur as non-mineral entities rather than discrete mineral particles, and are intimately distributed throughout the macerals; the distribution of these elements is very similar to that of organic S, particularly in the collotelinite and fusinite of the same coal samples.
Further, the applications of these studies in coal utilization such as: Coal Utilisation, Ultra-clean Coal Combustion, as well as CBM production and CO2 sequestration in coal seams, were presented. Finally, these studies permitted to draw the following conclusions:
Microprobe analysis can indicate:
•Coalification tracks of macerals with rank advance
•Rank in coals with suppressed reflectance
•Inorganic elements that may react unfavourably in combustion or gasification or may survive demineralisation processes
•Detailed nature of cleat and other mineralisation that may affect gas drainage or CO2 sequestration
•Micro-FTIR of macerals may further identify: Functional groups in different macerals, including aliphatic/aromatic characteristics of vitrinites with normal and suppressed reflectance
•Calcium may be a problem in slagging, but may have favorable catalytic effects in gasification Processes .
The Convenor wishes to encourage everybody who is working on new methodologies and/or developing novel techniques related to organic petrology, to share knowledge and submit an extended abstract, short communication or paper as a contribution to the White Paper II. Interested members should contact the Convenor.
The White Paper is dedicated to the memory of Marlies Teichmuller and Alex Cameron, and includes extended abstracts of the presentations given by invited speakers in Rio and Copenhagen meetings.