Why Envirocoal
 
 

...differentiated by its unique environmental properties because of its ultra low sulphur, ash and nitrogen contents

 

Ash Content 1%-2% (adb)
  • Lowest ash content among coals produced for global export trade, providing consumers with significant cost savings.
  • Blending Envirocoal with higher ash coal reduces the on-costs associated with ash disposal. This is significant in countries such as Japan, with limited ash disposal areas.
  • Low ash levels in Envirocoal also reduces deposition rates in boilers improving thermal efficiency and reducing maintenance costs.
 Coal Brands Within Global Export Trade
Nitrogen Content 0.9% (daf)
  • Envirocoal is amongst the 10 lowest coals by nitrogen content.
  • Low nitrogen content enables consumers to reduce the costs associated with removing nitrous oxides from the flue gases.
  • This results in more net power for sale and lower electricity production costs.
 Coal Brands Within Global Export Trade
Sulphur Content 0.1% (adb)
  • Regulation of emissions of sulphur oxides has required some consumers to install flue gas desulphurization equipment or to reduce the sulphur content in the blend of coals.
  • Envirocoal's ultra low sulphur content enables consumers to meet regulated standards and delay capital expenditure, reducing the cost of plant operation.
  • Desulphurization units can cost up to 20% of the total capital expenditure of a new power station.
 Coal Brands Within Global Export Trade

 

 

Special Focus: The Benefits of Envirocoal

 

 
 

Envirocoal is the best environmental solid fuel available. Gaseous emissions and particulate airborne emissions are lower than any other solid fuel. The amount of captured ash wastes are very small on an absolute basis and very low compared to other coals. The chemical composition of airborne and captured ash wastes renders them benign and suitable for recycling.

  
  • Environmental Benefits

  • Sulphur Oxides
    The occurrence of sulphur in Envirocoal is lower than nearly all coals in the world. Because of this, sulphur dioxide or SO2 emissions will be in the range 50 – 100 ppm or 0.20 – 0.26 lbSO2/mmBTU, lower than other coals, sometimes even with flue gas desulphurisation.

    Nitrogen Oxides
    The use of Envirocoal in most furnaces has resulted in lower nitrogen oxide or NOx emissions compared to other coals. In many cases, NOx emissions were reduced by as much as 40% when using Envirocoal as the sole feed. The exact amount of reduction will vary from unit to unit and also depends on the operating conditions.

    Dust Emissions
    In most dust collectors the particulate emissions of Envirocoal are approximately the same or less than other coals however some electrostatic precipitator tests have shown a marked reduction in emissions due to a combination of the very low inherent ash and the favourable fly ash resistivity.

    • SO2 emissions decrease
    • NOx emissions decrease
    • Opacity decreases
    • Wastes decrease

  • Economic Benefits

  • Once a power plant has been built, the cost of electricity or steam is aggregated into three cost areas. Envirocoal brings economic benefits to each of these.

    Fuel Cost
    Market conditions determine the fuel cost. With its expanding sales Envirocoal has shown itself to be competitive with higher rank coals on a per unit of energy basis

    Maintenance Cost
    Maintenance costs of pulverisers, coal pipes, boiler tubes and other equipment along the coal path are reduced because of the lessened impact of the ash.

    Operating Cost
    Envirocoal can be used to meet environmental regulations without the need for flue gas desulphurisation (FGD). This brings significant reductions in capital and operating costs by eliminating the need for a limestone scrubbing plant and its operating costs.

    Also in many cases it is possible to eliminate the cost of selective catalytic reduction (SCR) systems for NOx removal as Envirocoal’s emissions are low enough to meet the most stringent standards.

    • Impact on equipment decreases
    • No FGD required, or not required to operate
    • No SCR, or less NH3 and catalyst
    • More net power for sale
    • Unit availability increases
    • Less wastes for disposal

  • Technical Benefits

  • Storage
    Envirocoal is a low sulphur, low ash sub-bituminous coal that is easily stored with no detrimental effect to the environment. The leaching of the coal by rainwater during storage will occur however the characteristics of trace metals, chemical species and radionuclides in the coal are amongst the lowest in the world.

    Combustion
    Envirocoal is a reactive coal and in most cases it is not necessary to grind the coal as fine as other coals to burn well. This can result in less energy being required to grind the coal. The high surface area, combined with higher volatile matter, results in excellent ignition, stable combustion and near complete char burnout. Combustion efficiency is often greater than 99.7%.

    Ash
    In envirocoal, the amount of silica and alumina can be less than 60% with pyrites being low or non existent and ash particles being relatively small in size. This will result in much less wear and erosion when using Envirocoal.

    Ash Deposition
    Ash deposition is always a potential problem in coal-fired furnaces. The deposition rate from Envirocoal is much lower and sometimes non-existent. The experience from using the coal is that slagging is generally very low. The use of wall blowers and soot blowers, which reduce thermal efficiency, can be reduced significantly. Fouling is non-existent.





    Percentage of 0.1% Sulphur Coal Used

    Percentage of 0.1% Sulphur Coal Used


    1% Ash Coal 10% Ash Coal

    1% Ash Coal 10% Ash Coal