Master Thesis in Industrial Ecology

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Master Thesis in Industrial Ecology

• - Improvement of treatment methods for a
  coke-oven factory in Wuhai, Inner Mongolia

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Contents

• What is a coke-oven factory?
• Description of Wuhai
• Description of the company
• Different types of biological treatment
• Energy consumption, recycling
• Feasibility study
• Problems

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Coke-Oven Factory

• A more pure form of Coal
• Is needed to extract Iron from Iron Ore
• obtained from the destructive distillation of
  coking coals at temperatures of between 900 and
  1100C
• When heated in the absence of air, coal becomes
  buoyant ? volatile matter break down to yield
  gases, liquid and solid organic compounds of
  lower molecular weight and coke
• The production of coke requires water cooling and
  the use of water in by-products separation
• The resulting wastewater contains high amount of
  ammonia salts and toxic compounds such as
  phenols, PAHs, SCN- and CN-

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Description of Wuhai

• An industrial city with more than 450 000
  inhabitants
• Located in the Western part of EerDuoSi highland,
  Inner Mongolia, surrounded by three different
  deserts
• The HuangHe River goes from south to north
  through Wuhai City, length105 km
• Started to grow in the beginning of the sixties
  when they found coal and calcium carbonate in the
  area
• The main industries in Wuhai are coal, chemistry,
  construction material and metallurgy
• Most polluted city in Inner Mongolia

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Description of The Company

• Huaxi Jiohua Ltd. started to operate in 1992
• Produce 300 000 tones coke per yr
• 40 of the treated wastewater goes directly to
  the Yellow River
• The present treatment methods doesnt reduce the
  amount of phenol good enough
• recycle 45 of energy, supply Wuhai City with
  the rest 55

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Flow Diagram of the Company
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Biological treatment

• Active Sludge Process (most common)
• - a big aerobic tank
• Combinated AS process and biofilter (recommended)
• Sequential Batch Reactor (best method according
  to research)
• - a reactor with an anerobic/aerobic and a
  settling down step

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The companys treatment methods
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Active Sludge Process
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Energy

• The company recycle 45 of the produced energy
• Supply the Wuhai City with the rest
• Need to enhance the recycling
• Electricity 15 kWh/ ton coke
• Wastewater 88kWh/h ? 7200 h/year ? 633600 kWh

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Feasibility Study

• To Improve the present treatment methods
• Do an economical calculus for the improvements
• Suggest an improvement for energy and wastewater
  water recycling
• Compare the present methods with the most common
  methods in Western Countries

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PROBLEMS

• Wrong Data supported from the company
• The management dont want to support with useful
  info about the present methods ? Not knowing the
  present methods make it difficult to be able to
  improving them
• New info if the company not improving their
  methods before dec 2007 it going to close down,
  if do ? Close down dec 2009

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THANK YOU For Listening!

• Gabriella Alexandersson
• Post Graduate Student, Industrial Ecology
• Royal Institute of Technology