Mechanical five-step process
White Energy’s BCB technology upgrades coal and coal fines through a relatively simple thermal drying process followed by physical and chemical stabilisation via a novel binderless briquetting process. The BCB technology has been developed over 20 years, by a consortia led by the CSIRO.
RAW COAL PREPARATION Coal from the mine is delivered to the BCB plant site and is deposited into a raw coal buffer storage bunker. The coal then undergoes primary, and if required, secondary crushing. In the instance of the coal being upgraded is coal fines, generally crushing is not required prior to processing.
COAL DRYING Hot gas is required to dry the raw coal and/ or coal fines. Hot gas is generated in a furnace fired on a combination of dried coal dust from the briquetting machines and dried coal from the cyclone coal surge bin. Hot gas is then exhausted from the furnace directly into the drying column. The raw coal and/ or coal fines is “flash dried” in the drying column where water in the coal is essentially evaporated off.
SOLIDS SEPARATION The coal which is transported within the drying column using the flow velocity of the heated drying gas, is then separated from the now moisture laden gas using a pneumatic cyclone.
BRIQUETTING OF DRY COAL The briquetting process involves the transportation of dry coal product downstream of the dried coal buffer bin, feeding the material to the briquette presses, briquetting, cooling the briquette product and placing it on a stockpile. This is done as a continuous process, taking only minutes for the material to move from being a raw, high moisture, low energy coal, into low moisture, high energy briquette.
COOLING CONDITIONING Cooled briquettes are placed on the open-air stockpile in preparation for transport. The briquettes continue to stabilise on the stockpile where they will reach their stable or ‘equilibrium’ moisture content. BCB is produced only marginally below this equilibrium moisture, so the total moisture of the stockpiled BCB product is considered very similar to that of the customers as-received properties.
The binderless briquettes are held together by the natural bonding mechanisms of coal and do not require any binders that are normally used to briquette coals.
The upgraded coal is intended to be used interchangeably with other high ranking, low moisture coals and does not require any technical or engineering alterations at the power stations to allow for coal combustion. The inter-changeability of White Energy’s BCB coal at the power station allows White Energy to take advantage of the significant price arbitrage opportunity created by the low cost of feedstock and the historical market price for bituminous coal.
White Energy’s BCB technology has been shown to be operationally superior to competing processes and enables the commercial exploitation of a large number of low quality, high moisture coal deposits. White Energy’s BCB coal upgrading process provides coal fired power stations and other industrial applications with an opportunity to burn a cleaner and more efficient fuel.
Advantages of the BCB Coal Upgrading Process
|Simple mechanical process||The BCB technology uses a simple mechanical process. It does not require expensive binding agents to stabilise the upgraded product which would otherwise impact its combustion characteristics and/ or marketability. The process is designed to work at the mine site to create a product with a controlled and consistent size and chemistry|
|Competitive upgrading costs||White Energy’s BCB upgrading process has demonstrated an ability to convert low cost, low rank coals to bituminous quality thermal coal at a competitive price. More recently the BCB process has been successful in briquetting bituminous and other higher rank coal fines|
|Time to market||White Energy’s BCB process possesses first mover advantage over potential competitors in the field of industrial scale clean coal upgrading and/or briquetting|
|Modular system and deployment strategy||The BCB technology is designed for deployment in modules that can process up to one million tonnes of upgraded coal per annum. This design allows the deployment to be staged on a module-by-module basis which minimises operating and financial risk, optimises capital management as well as allowing for geographic and site diversity|
|Flexible feedstock||White Energy’s BCB upgrading process is effective for both the upgrading of high moisture coals as well as high energy discard coal fines into a stable transportable briquette product|
|Broad geographic application||Coals from around the world have been successfully upgraded using the BCB technology, including coals from Indonesia, China, the USA, South America, India, Africa and Russia|
|Integrate into coal gasification / poly-generation systems||White Energy’s BCB upgrading process produces an ideal feedstock that is suitable for integration into coal gasification / poly-generation systems.|
Benefits of BCB Upgraded Coal
The upgraded coal produced by the BCB process has the following characteristics:
Higher energy content
|Increased energy content as compared to low rank sub-bituminous feedstock by between 30% and 200% (depending on the original moisture content of the coal)|
|Reduced CO2 emissions||In comparison to sub-bituminous feedstock, White Energy BCB upgraded coal has lower CO2 emissions and other pollutants at combustion|
White Energy BCB upgraded coal maintains the positive attributes of low rank sub-bituminous feedstock such as lower ash and SOx content as compared to high rank bituminous thermal coals
|Reduced levels of coal dust||
White Energy BCB upgraded coal has significantly lower dust quantities when compared to unprocessed sub-bituminous coal which increases railway efficiency and reduces environmental impact
|Lower transportation costs||
White Energy BCB upgraded coal has up to 40% less moisture, resulting in a decrease in load volumes and concomitant transportation costs
|Interchange-ability with bituminous coal||
Sub-bituminous feedstock coal upgraded by the White Energy BCB process compares favourably with higher priced bituminous coals, highlighting the economic opportunity for White Energy and the environmental incentive for energy consumers
|Reduction in boiler mill power for milling the fuel to the furnace||
White Energy BCB upgraded coal requires much less milling power and could be an attractive option for mill constricted boilers to increase throughput
Key metrics of coal performance
In addition, there are a number of benefits to power utilities arising from burning BCB Upgraded Coal with its low sulphur and low ash characteristics, as opposed to similar energy value high ash coals. These benefits include:
- Increased power output and improved heat rate;
- Enables higher capacity utilisation;
- Enables increases life expectancy of assets;
- Increased boiler efficiency;
- Improved environmental performance;
- Reduced residual waste for disposal; and
- Solution to meeting stricter environmental and emissions regulations.