Solutions to RTAs SO 2 Pollution Problem Greg Knox SkeenaWild - - PowerPoint PPT Presentation

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Solutions to RTAs SO 2 Pollution Problem Greg Knox SkeenaWild - - PowerPoint PPT Presentation

Jun 22, 2023 222 likes •363 views

Solutions to RTAs SO 2 Pollution Problem Greg Knox SkeenaWild Conservation Trust What are the options for reducing SO 2 ? Where is SO2 emitted at the smelter? 7% 75% 18% Strategies to Reduce SO2 Emissions Use low sulphur petroleum

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SLIDE 1

Solutions to RTA’s SO2 Pollution Problem

Greg Knox SkeenaWild Conservation Trust

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SLIDE 2

What are the

  • ptions for

reducing SO2 ?

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SLIDE 3
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SLIDE 4

Where is SO2 emitted at the smelter?

75% 7% 18%

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Strategies to Reduce SO2 Emissions

  • Use low sulphur petroleum coke
  • Use pre-calcined coke
  • Use prebaked anodes
  • Reduce aluminum production
  • Install SO2 scrubbing technology
  • A combination of the above
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SLIDE 6

Viable Options

  • Wet scrubbing using sodium (soda ash)
  • Wet scrubbing using seawater
  • Wet scrubbing using limestone
  • Wet scrubbing using lime
  • Dry scrubbing using lime (circulating dry

scrubber)

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SLIDE 7
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Environmental Impacts of Seawater Scrubbing

  • Uses large volumes of seawater (8000 m3 / hour)
  • SO2 reacts with with seawater and turns into sulfate
  • Sulfate naturally occurs in high concentrations in seawater

(increase in sulfate approx 5%)

  • Returned seawater controlled to a

pH of 6 – pH of 6.5

  • Temperature increase typically 1 – 2 0C

No significant impacts to the ocean

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Environmental Impacts of Dry Scrubbing

  • Lime reacts with SO2 to form gypsum (drywall)
  • Gypsum has no harmful environmental impacts, but requires

disposal in a landfill No significant Impacts to to th the land

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Scrubbing Costs

  • $100 million to install scrubber to keep SO2 at pre KMP levels
  • $200 million to install scrubbers to reduce SO2 by over 90%
  • Plus annual operating costs
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Industrial Use of SO2 Scrubbers

  • Used in 20 aluminum smelters around the world (i.e. Norway,

Quatar)

  • Studies of these facilities, no significant harm to the

environment

  • Used in other types of smelters and coal fired power plants

(extensively in china)

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SLIDE 12
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Benefits of Scrubbing

Community

  • Impacts of SO2 pollution not born by citizens
  • Little or no acid rain
  • More jobs installing & operating scrubbers

RTA

  • Recognized as world leader in protecting peoples health & the

environment

  • Offset costs of scrubbing with being able to use lower cost

petroleum coke

  • Build a healthier relationship with local citizens, leaders, and

its own union