Densified coal
Encyclopedia
Densified coal is the product of the Coldry Process coal
upgrading technology that removes moisture from low-rank coals such as sub-bituminous and lignite
/brown coal. The densification process raises the calorific value of low rank coal to equal or exceed that of many export grade black coals. Densified coal resulting from the Coldry Process is regarded as a black coal equivalent
or replacement for black coal.
near Bacchus Marsh, Victoria
, Australia
. The mine operator identified that hardened bitumen-like road surfaces formed naturally and spontaneously after heavy trucks churned up brown coal fines with moisture from rainfall when the trucks entered and left the mine. In the days that followed a rain event the road surfaces at the mine would harden like tarmac and no longer absorb water. Dr Johns and colleagues identified a process of low-mechanical shear had occurred where brown coal mixed with a small amount of moisture and subject to low-level mechanical shear had triggered a natural exothermic reaction process within the coal leading to the expulsion of its moisture content. The process fundamentally alters the micro chemical bonds within the coal, naturally reducing moisture content to around 11 per cent; boosting calorific value over 5600 kcal/kg; and creating a new ‘densified coal’ product that is hydrophobic, no longer prone to spontaneous combustion, and readily transportable.
, and Newcastle New South Wales
Australia.
adb = as dry basis. ar = as received. db = dry basis. wb = wet basis.
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
upgrading technology that removes moisture from low-rank coals such as sub-bituminous and lignite
Lignite
Lignite, often referred to as brown coal, or Rosebud coal by Northern Pacific Railroad,is a soft brown fuel with characteristics that put it somewhere between coal and peat...
/brown coal. The densification process raises the calorific value of low rank coal to equal or exceed that of many export grade black coals. Densified coal resulting from the Coldry Process is regarded as a black coal equivalent
Black coal equivalent
Black coal equivalent is a term applied to describe the properties of an export coal product derived from the Coldry Process, a patented coal upgrading technology operated by Environmental Clean Technologies Limited, in Victoria, Australia...
or replacement for black coal.
Overview
Densified coal as an ostensibly ‘new’ product emanating from brown coal was first identified by Dr R.B. Johns and colleagues at the Organic Chemistry laboratory at Melbourne University following observations made at the Maddingley MineMaddingley Mine
Maddingley Mine near Bacchus Marsh Railway Station, Victoria, Australia contains a concentration of a particular brown coal formation called Leonardite. A relatively high altitude formation, Maddingley brown coal is distinguished as having 60 per cent moisture content and a rich fulvic acid and...
near Bacchus Marsh, Victoria
Victoria (Australia)
Victoria is the second most populous state in Australia. Geographically the smallest mainland state, Victoria is bordered by New South Wales, South Australia, and Tasmania on Boundary Islet to the north, west and south respectively....
, Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
. The mine operator identified that hardened bitumen-like road surfaces formed naturally and spontaneously after heavy trucks churned up brown coal fines with moisture from rainfall when the trucks entered and left the mine. In the days that followed a rain event the road surfaces at the mine would harden like tarmac and no longer absorb water. Dr Johns and colleagues identified a process of low-mechanical shear had occurred where brown coal mixed with a small amount of moisture and subject to low-level mechanical shear had triggered a natural exothermic reaction process within the coal leading to the expulsion of its moisture content. The process fundamentally alters the micro chemical bonds within the coal, naturally reducing moisture content to around 11 per cent; boosting calorific value over 5600 kcal/kg; and creating a new ‘densified coal’ product that is hydrophobic, no longer prone to spontaneous combustion, and readily transportable.
Characteristics of densified coal
The chemical and calorific values of densified coal derived from typical Victorian brown coal with a natural average moisture content of 60 per cent by weight compares well with typical high grade black coal exported from Tarong QueenslandQueensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, and Newcastle New South Wales
New South Wales
New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...
Australia.
Chemical composition
| Name | C Carbon % | H Hydrogen % | N Nitrogen % | O Oxygen % | S Sulfur % |
|---|---|---|---|---|---|
| Victorian Brown Coal (Lignite) | 26.6 | 1.93 | 0.21 | 9.4 | 0.39 |
| Densified Brown Coal (Coldry ) | 59 | 4.24 | 0.46 | 21 | 0.85 |
| QLD Black Coal (Export) | 52 | 2.59 | 0.74 | 11 | 0.25 |
| NSW Black Coal (Export) | 48.9 | 3.29 | 1.19 | 10.1 | 0.81 |
Comparison of calorific values
| Name | Moisture % | Volatiles % | Fixed Carbon % | Ash % | Sulfur % | Net Weight Specific Energy |
|---|---|---|---|---|---|---|
| Morwell Brown Coal (Lignite) | 59.3% wb | 20.0% wb | 19.86% wb | 0.9% wb | 0.3% db | 2006 kcal/kg ar 8.4 Mj/kg ar |
| Tarong Black Coal (Export coal) | 15.5% adb | 22.5% wb | 44.1% wb | 17.9% wb | 0.42% wb | 4800 kcal/kg adb 20.1 Mj/kg adb |
| 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
- Bituminous coalBituminous coalBituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than Anthracite...
- Bergius processBergius processThe Bergius Process is a method of production of liquid hydrocarbons for use as synthetic fuel by hydrogenation of high-volatile bituminous coal at high temperature and pressure...
- Coal assayCoal assayCoal Analysis techniques are specific analytical methods designed to measure the particular physical and chemical properties of coals. These methods are used primarily to determine the suitability of coal for coking, power generation or for iron ore smelting in the manufacture of steel.-Chemical...
- Coldry ProcessColdry ProcessColdry Process is a coal upgrading technology developed in Victoria, Australia by Environmental Clean Technologies Limited to specifically beneficiate low-rank brown coal and sub-bituminous coal by removing natural high moisture content and certain pollutants; harden and densify the coal; raise...
- Energy value of coalEnergy value of coalThe energy value of coal, or the fuel content, raj is the amount of potential energy in coal that can be converted into actual heating ability. The value can be calculated and compared with different grades of coal or even other materials...
- Orders of magnitude (specific energy density)Orders of magnitude (specific energy density)This is a table of specific energy densities by magnitude. Unless otherwise noted, these values assume standard ambient temperature and pressure....
- Fischer-Tropsch processFischer-Tropsch processThe Fischer–Tropsch process is a set of chemical reactions that convert a mixture of carbon monoxide and hydrogen into liquid hydrocarbons. The process, a key component of gas to liquids technology, produces a petroleum substitute, typically from coal, natural gas, or biomass for use as synthetic...
- Karrick processKarrick processThe Karrick process is a low-temperature carbonization and pyrolysis process of carbonaceous materials. Although primarily meant for coal carbonization, it also could be used for processing of oil shale, lignite or any carbonaceous materials. These are heated at to in the absence of air to...
- LeonarditeLeonarditeLeonardite is a soft waxy, black or brown, shiny, vitreous mineraloid that is easily soluble in alkaline solutions. It is an oxidation product of lignite, associated with near-surface mining...
- Maddingley MineMaddingley MineMaddingley Mine near Bacchus Marsh Railway Station, Victoria, Australia contains a concentration of a particular brown coal formation called Leonardite. A relatively high altitude formation, Maddingley brown coal is distinguished as having 60 per cent moisture content and a rich fulvic acid and...
- List of CO2 emitted per million Joule of energy from various fuels