Black coal equivalent

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Black coal equivalent (BCE) is an export coal product derived from the Coldry Process, a patented coal upgrading technology operated by Environmental Clean Technologies Limited, in Victoria, Australia. The Coldry Process is applied to Victorian brown coal (lignite) with a typical moisture content of 60 per cent by weight and transforms the coal into a new densified coal product of equal or better calorific value (5,800 kcal/kg) to typical export quality Australian black coal, with less ash and sulfur content. Black coal equivalent derived from Victorian brown coal is ostensibly a 'cleaner' burning coal fuel than most black coals.

Overview[edit]

Densified coal as an ostensibly ‘new’ black coal equivalent product derived from Victorian brown coal was first discovered by Dr R.B. Johns and colleagues at the Organic Chemistry laboratory at Melbourne University following observations made at the Maddingley Mine near Bacchus Marsh, Victoria. Dr Johns and colleagues identified that a process of low-mechanical shear applied to brown coal mixed with a small amount of moisture would trigger a natural exothermic reaction process within the coal, leading to the expulsion of its moisture content.[1] The process fundamentally alters micro chemical bonds within the coal, naturally reducing moisture content to around 11 per cent; boosting calorific value to around 5800 kcal/kg; and creating a new ‘densified coal’ product that is hydrophobic, no longer prone to spontaneous combustion, and readily transportable. For the operators of black coal generators, densified coal is described as a black coal equivalent that offers the advantages of less ash and sulfur content often associated with many black coals.

Characteristics[edit]

The performance characteristics of black coal equivalent densified coal derived from Victorian brown coal is benchmarked[2] against the comparative burning properties of black coal mined and exported from mining regions in Tarong, Queensland and Newcastle, New South Wales, Australia. Black coal sourced from Tarong and Newcastle constitute the bulk of black coal currently exported by Australia. Black coal equivalent has become an attractive option to coal importers from countries such as Vietnam as the product burns like black coal in black coal boilers, yet is a 'cleaner' burning product that reduces plant maintenance and upkeep cost.

Chemical composition[edit]

Name C Carbon % H Hydrogen  % N Nitrogen % O Oxygen % S Sulfur %
QLD Black Coal (Export)

Tarong

52 2.59 0.74 11 0.25
NSW Black Coal (Export)

Newcastle

48.9 3.29 1.19 10.1 0.81
Black coal equivalent

Densified Brown Coal (Coldry )

59 4.24 0.46 21 0.85

Comparison of calorific values[edit]

Name Moisture % Volatiles % Fixed Carbon % Ash % Sulfur % Net Weight Specific Energy
Queensland Black Coal (Export)

Tarong

15.5% adb 22.5% wb 44.1% wb 17.9% wb 0.42% wb 4800 kcal/kg adb

20.1 MJ/kg adb

NSW Black Coal (Export)

Newcastle

3.3% adb 26.5% wb 46.0% wb 24.2% wb 0.42% wb 5681 kcal/kg adb

23.79 MJ/kg adb

Black coal equivalent

Densified Brown Coal (Coldry)

12.0% adb 48.9% wb 49.1% wb 2.4% wb 0.3% wb 5874 kcal/kg adb

24.6 Mj/kg adb

Percent by weight

adb = as dry basis. ar = as received. db = dry basis. wb = wet basis.

See also[edit]

References[edit]

  1. ^ Johns, R.B., Chaffee, A.L., and Verheyen, T.V. International Conference Coal Science, Düsseldorf 1981
  2. ^ CSIRO: Review data Australian coals 2009

External links[edit]