Model for Beneficiated Coal

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Model for Beneficiated Coal

• dr kalyan sen
• Prof. Emeritus, Bengal Engineering Science
  University,Shibpur
• Director, Central Coalfields Ltd.
• Former Director, Central Fuel Research Institute
  and Central Mining Research Instutute, Dhanbad.
• 9th International Summit Expo POWER INDIA 2007
• 25-27 October 2007 Mumbai, India.

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Coal Scenario

• Likely to treble in the next decade
• Largest consumer Power Utilities
• Most of the TPP burn coal without any upgrading
• Coal cleaning is one of the important action
  areas for achieving reduction in CO2 emission per
  kWh of electricity produced.

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Barriers for Coal Beneficiation

• Difficult washability characteristics of Indian
  Coals due to Geological reasons.
• Back dated mining and preparation technologies
• Uncertainty associated with the economic impact
  on the down stream processes.

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Silver Linings

• Indian coals contain low Sulphur
• Combustibility is good due to Geological reasons
• Coal washed up to 55 elementary ash (equivalent
  to 34 overall ash) has good combustion
  properties

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Action Desired

• To transform from a qualitative understanding of
  the effect of coal quality parameters to a
  quantitative domain
• An economic model considering several factors
  involved throughout the mine-energy chain
  like-
• cost of coal, logistics, beneficiation
  technologies, efficiency improvements
  environment benefits

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Models for Beneficiated Coal

• Coal Data Base
• Simulation of Coal Beneficiation Process
• Cost Model

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Coal Data Base

• Full scale size-wise washability data
• Fraction-wise chemical, heat value and ash
  composition data
• Prediction of the quality parameters of the
  cleans
• Studies on Combustibility of washed coal and
  slagging and fouling problems by Drop Tube
  Furnace tests

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Options of Beneficiation Process

• Destoning followed by whole coal beneficiation
• Combination of Dry and Wet schemes
• Blending partly washed coal with unwashed lower
  size fractions
• Use of the concept of limiting elementary ash
  to identify the optimum ash content for power
  generation
• Multi-product washing schemes

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Simulation of Coal Beneficiation Process

• Computer simulation of washability data (from
  module1) and efficiency of washers to identify
  optimum operation conditions to produce maximum
  yield at desired quality
• Based on the washability potential the best
  economic option should be chosen

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Cost Model

• Cost and Quantity of raw coal
• Transportation costs ( mine to washery and
  washery to power plant)
• Scope and cost of Reject utilization
• Savings in GHG generation at different levels of
  cleaning
• Savings due to reduction in maintenance, ash
  handling, etc.
• Savings due to improvement in energy efficiency

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Conclusions

• New coal washeries of total capacity 100mt/yr
  should be created within a decade. Modules of
  2.5, 5 and 10my/yr are techno-economically
  justified
• Regulatory framework should be enforced to fix up
  the price of washed coal considering cost of
  production and direct indirect benefits
• Model for Beneficiated Coal should be utilized to
  help in decision making.

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THANKS