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1
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- CASE STUDIES
- Gaétan Noël, M.Sc. eng.
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2
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- 3 lines TMP process
- 2 paper machines
- 550 t/d of specialty papers
- Objective: effluent cooling down to 37°C for the secondary effluent
treatment plant
- Maximum payback of 2 years
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3
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- Many crucial projects identified during the data extraction phase:
- Replace fresh water by W.W. for the TMP steam scrubber
- Adjust (reduce) refiners cooling water consumption
- Recalibrate temp. sensor on one PM W.W. system
- Close the steam heater for the refiners ’ dilution water
- Modify controllers' adjustements of fresh water users to reduce
temperature and flowrate variations
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4
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- Annual energy savings of these modifications estimated at 245 k CDN$/yr
with the process simulator (less energy in the effluent)
- Estimated effluent and fresh water consumption reduction of 3100 m3/day
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5
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6
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7
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8
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9
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- 3 lines TMP mill
- Deinking process
- 3 paper machines (newspaper)
- 1200 t/d
- Objectives: effluent cooling below 40°C
- Payback around 1 year required
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10
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- Targeting based on effluent temperature: dTmin of 10°C selected
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11
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- The solution: 3 projects
- in 3 phases
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12
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13
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- Observed results after phase 1:
- effluent temperature reduced by 3.0 deg. C
- savings of 670 k CDN$/year
- cost of 600 k CDN$
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14
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- Energy savings found were equal to 20% of the fossil fuel bill for a
1-year payback period
- Energy saving measurements for phase 1 were right on the target
- The findings of the data extraction phase represent a large portion of
the total savings and can easily pay for the study within a few weeks
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Notes
