Black coal equivalent

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 brown coal (lignite) with a typical moisture content of 60 per cent by weight and transforms the coal into a densified coal product of equal or better calorific value (5,800 kcal/kg) to typical export quality black coal, with less ash and sulfur content. Black coal equivalent derived from brown coal is ostensibly a 'cleaner' burning coal fuel than most black coals.

Overview

Densified coal as a black coal equivalent product derived from 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 ‘densified coal’ product that is hydrophobic, no longer prone to spontaneous combustion, and readily transportable.

Characteristics

The performance characteristics of black coal equivalent densified coal derived from 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 with no or few reserves of domestic black coal.

Chemical composition
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
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

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