Emissions Testing at PG Pulpmills

1
Emissions Testing at PG Pulpmills

• Presentation to Research Working Group
• Canfor Administration Centre
• September 28, 2004

2
Introduction

• Quarterly Stack Test Program
• Purpose
• Run rates during stack testing
• Mass emissions vs Permit Limit
• Consistency of total mill emissions over time
• Test frequency other jurisdictions
• Soot Blowing
• Opacity Measurements
• PM Emissions Reduction
• Summary of Emissions Overstatement

3
Quarterly Stack Test Program

• Recoveries, Power Boilers, Smelt Stacks, Lime
  Kilns 18 stacks in total
• Testing performed by a third party McCall
  Environmental
• Purpose
• Ensure Permit compliance at operating rates
  representative of full mill production (not
  designed for airshed management)

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Quarterly Stack Test Program contd

• Use of data for a daily emissions assessment can
  lead to error lets compare to effluent source
  testing to illustrate
• Fluid effluent samples taken at more frequent
  intervals (daily), irregardless of process
  conditions, and uses time interval composite
  sampling.
• Can be used to assess contribution to receiving
  environment in addition to compliance measurement
• Effluent is mixed, treatment system has 6 to 8
  day retention time.
• Cost of Testing is very different (for example,
  110,000 / yr _at_ Northwood mill for daily analysis
  vs. 80,000 / yr for 1 set of results each
  quarter)
• Only one source of effluent to the receiving
  environment very easy to assess and study

5
Quarterly Stack Test Program contd

• Operating rate requirements
• Air emission testing takes place quarterly and is
  more affected by process conditions at time of
  testing.
• No mixed emissions, the test result is
  representative of the time of testing. The two
  one hour tests only tell what is happening for a
  two hour period
• Testing is much more expensive in time and money
• Each source takes about 10 man hours.
• Cost is about 1300 per stack.
• 18 different sources all different

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Run Rates _at_ Sampling Northwood 2 Power
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Run Rates _at_ Sampling Northwood 4 Power
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Run Rates _at_ Sampling - Intercon

• Chart?

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Run Rates _at_ Sampling - PG
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Run Rates _at_ Sampling - PGSPP
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Run Rates _at_ Sampling PGSPP contd
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Mass Emissions vs. Permit Limit

• Most Permit Limits expressed in maximum rates of
  flow and maximum concentrations
• E.g. for PGSPP Recovery Boilers . . .
• Max flow is 6,060m3/min
• Max PM concentration is 230mg/m3
• Real emissions at both limits would be 84kg/hr

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Mass Emissions vs. Permit Limit - Northwood
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Mass Emissions vs. Permit Limit Intercon PGSPP
15
Soot Blowing

• Soot blowing process
• Steam is blown at the boiler tubes inside
  boiler chamber upsteram of pollution control
  equipment in order to dislodge soot and saltcake.
  It is not chimmney or stack cleaning.
• Required to clear soot from boiler tubes
  (interferes with steam generating capacity, can
  plug boiler and can become a hazard if not blown
  off)
• Frequency and duration at Northwood and PG Pulp
• Soot blow each Power Boiler for 2hrs per day at
  Northwood, PGSPP,
• Soot blow all Recovery boilers on a continuous
  cycle in alternating sections of the boilers
• 1998 Intercon PB Precipitator
• Soot blowing redirected through new precip
  (still 2hrs per day every day)
• Mill-wide emissions 50 of previous
• No apparent impact on ambient PM levels

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Opacity Measurement

• How it works
• How we utilize this instrument as an operating
  guide
• Reliability Issues
• Drift over time
• Spikes due to larger particles, fog,
• Examples (high readings when mill down or boiler
  is off hog)
• No flow data cant correlate with emissions

17
PGI PM Emissions Reduction to Q3 2004
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Trends in Annual Average PM at Plaza 400

• Burner Shut downs
• NCP - 05/92
• Dollar Saver - 11/93
• Lakeland Mills - 11/93
• The Pas - 03/95
• Westhill Lbr - 06/95
• PG Wood - 11/96
• Carrier Planer - 11/96
• Stella Jones - 12/96
• NOM - 03/99
• Carrier Sawmill - 10/99
• Rustad - 12/2000
• Other
• Intercon Recovery Boiler Rebuild - 1993
• Northwood Pulp precipitator chamber on recovery -
  1994
• NCP Precipitator -11/96
• Intercon precipitator on power boiler - 1998
• Intercon cogeneration - 2000

52 reduction PGSPP/Intercon '98 to '03
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Summary of Emissions Overstatement

• Testing at higher than average run rates
• 22 hr/day boiler operations
• Power Boiler hours on natural gas not accounted
  for
• Annual maintenance shutdowns

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In Closing . . .

• Emissions are significantly overstated providing
  for conservative impact modeling
• Step change improvements at PGSPP and Intercon
• Other than step changes, combined mill emissions
  are stable over time
• Pulpmill emissions are, by far, the best
  characterized of all sources in the airshed

21
Some Interesting Info.

• Cost current sampling program is it 180,000
  for 3 mills
• Northwood PM trend
• Installed Dry Ash collection system on 4 Power
  Boiler
• Plugged 20 of 4 PB secondary multiclones to
  optimize multiclone flue gas flow rate vs.
  particulate removal rates. Planning to plug 20
  of the primary multiclones to further improve
  this.
• Planning to plug 20 of 2 PB multiclones for
  similar reasons