Paptac
Bleaching Committee
Section 7:
Opportunites and Problems Section
October 21, 2002
MILL OPPORTUNITIES
Marathon Pulp Inc. -
Jim Collins (reported by Paul Earl)
1)
Established new safety record in June 2002.
·
1,065 days without a Lost‑Time Injury
·
1,667,868 person‑hours
2) New Annual
Pulp Production Record:
- Fiscal Year
2002 (Sept. 30, 2001 to September 28, 2002)
- 182,970
BADMT
- Best
Previous ‑ 176,723 BADMT ‑ 1999
3) New Digester White Liquor Feed System ‑
Direct fill to batch digesters
- From white liquor storage
bypassing WL day tank.
- Will allow increased white
liquor flow to digesters
- for potential production
increase
4) Installation of Thermocompressor on
steam feed to pulp machines
- This will
allow higher steam pressure to pulp machine to increase heat
transfer
- Expect to
get increase in pulp dryness from current 84‑86 % AD
Abitibi-Consolidated- Kent Ramsay
1)
Annual shutdown extremely successful.
2)
Three daily production records – last two months.
3)
EcoBrite (bleach enhancer) trials. Reduction in ClO2
4)
Looking at Process Control Upgrades for peroxide: O2 addtion
(RF)
5)
#6 Digester made the same as Dig 1-5, 7. Kappa St. Dev.
Improvements
6)
Env. No exceedances this year.
7)
Not much capital
8)
Flash Dryer upgrades required.
St. Anne Nackawic –
Tim Gillis
1)
Mill running well- setting daily and monthly production
records in July.
2)
Cost reduction and Environmental goals continue to be
paramount.
3)
No major capital projects.
4)
Improved controls in Bleach Plant.
5)
Do control working fine.
6)
Implementing dosage control.
7)
Increasing bleach shower flows.
8)
Increased hog fuel burning has reduced energy costs
9)
enzyme trial upcoming.
Celgar Pulp Co. –
Ralph Lunn
1)
New record in September: 1289 t/day average, 97% on grade
2)
Browstock Pressure Diffuser (from Gold River) installation underway.
Complete February 03
3)
Kappa analyzer installation complete mid-November
4)
Weld overlay of additional 16’ in digester.
5)
New Avtron drives and Fisher Delta V Controls on #4 pulp
machines
Pope & Talbot
Harmac Pulp Operations – Murray Walters
1) R8 Plant
control now via Delta V DCS
2)
Cs control installed on stock flow to 1 and 2 Pulp Machines
3)
Partial DCS conversion (to Delta V) in all 3 Pulp Machines
4)
Embarking on batch digester renewal program.
5)
Continuous precoat renewal systems to be installed in LMF’s.
Canfor, Prince George
– Lance Anderson
1) Absolute
brightness project still continuing to build supervisory.
2) New sampler
installed on major shut
3) Generator
control supervisory (FTNIR) working well – Significant reduction on NaClO3
usage.
4)
Very little capital spent.
Tembec Skookumchuck –
Kari Rae and Gavin Baxter
1)
Formaldehyde – 3 trials
2)
Other improvements (radial wash) interfere.
3)
Lowered Cl02 usage—saving Cl02 but not
enough to cover cost of HCHO. Chemistry works.
4)
Spent Acid addition to D2 ST for pH control.
5)
Implemented radial wash, reduction of 6 Kg/ADt
6)
Cogeneration plant now functioning near design
7)
Updating pinch study
Howe Sound Pulp &
Paper Limited Partnership – Gerry Pageau
1)
Energy savings from F11
project - -now allowing running cold blow cooler with mix for warm and cold
water, higher blow line temp – less steam in digester and bleach.
2)
Just installed new DCS ( ABB Advant) in pulp machine and
cleaners area
3)
Fully integrated motor and valve controls from stock prep to
scanner
DMI – Peace River –
Guy Normandeau
1)
Digester downflow low solids project commissioned Oct. 15/02.
2)
Advanced Bleach plant controls will be completed in November
(with new bleach plant kappa/bright analyzer).
3)
Warm water into Recaust.
Kruger Inc. – Alain
Bergeron
1)
Construction of a new paper machine which will produce 750 TPD
of light-weight coated paper -
-Start-up
Fall 2003.
2)
Installation of a Kappa analyser on the blow line – June
shutdown.
3)
Installation of an Alkali analyser.
4)
Put digester on DCS
5)
Uncooled chip recovery system
Cascades FjordCell –
Michel Aucoin
1)
Addition of surfactant (Chemstone) gives 8% boost on our
production, with the same loading at the boiler.
2) Putting chemical air remover to
increase dryness by around 2-4%. It also increases the ceiling, production of
our pulp thickener machine.
3) Resolve our
fouling at the boiler by changing NaOH,
and improve sesqui washing.
Domtar Espanola -
Brian Gartley
1) Previous
year spent on Optimization with focus on energy and cost.
Kappa analyzer being installed.
2)
Management change at mill. Fred Munro is now the Director at
Process and Product Development. His rolin Paptac bleaching may be reduced.
3)
Polysulphide project is on hold due to operational issues at
the kilns. (Not related to PolyS).
Domtar, Inc. - Azim Shariff
1)
Domtar expansion to the
U.S. – 4 G.P. Mills.
2)
Integration has been completed.
3)
Marginal economics to feed sweet spot for operating to
maximize cash flow in a down market.
4)
Mill managers no longer chasing production records.
Cariboo – Ted Tam
1)
Installed Gemini nozzels in the sootblowers – Realized 25-30%
steam savings.
2)
Upraded turbo-generator for higher efficiency and increased
capacity.
3)
In the process of installing a hi-sheer mixer in Eo stage to
improve delignification.
Sterling Pulp
Chemicals – Jim Hopmans
1)
Jim Davidsons (Sterling Technical Service R& P) will be
retiring next year after (many) years of service.
We are wellin
the process of hiring his replacement to ensure that a higher level of service
is maintained.
2)
Sterling’s supervisory (advanced) control system known as
Erco-Smarts is completing its 1st year of
successful commercialization at a
Mead-Westvaco Mill. Mead-Westvaco has ordered
similar systems for all of their mills. Negotiations are underway for
installation at several Smurfit Mills as well as Sappi-North America mills.
3)
Sterling successfully commissioned its first atmospheric
hydrogen peroxide-based chlorine dioxide process (known as AHP) at a mill
location in Finland. Start-up was hampered by dirty feed chemicals but is
currently operation above design capacity and in line with all design
parameters.
ALPAC – Ralph
MacDonald
1)
Set new SW/HW production rates (1 day average)
2)
Modified pulp machine suction press roll.
Paprican – Jean Bouchard
1)
The start-up of our new
chlorine dioxide generator went very well and now allows us to do real
pilot-scale trial and contract.
2)
Our financial situation has improved since the federal
government has decided to involve itself with Paprican, Ferric, and Forintek
and also because a couple of new members have joined.
Air Liquide - Gord Homer
1)
Well into the construction of a 65-ton VSA at
Bowater-Catawlka- SC.
2)
Work on effluent colors and low consistency application of
ozone continues.
3)
Work continues on ozone metallurgy
4)
A second molecular white liquor oxidation system ordered.
MILL PROBLEMS AND SOLUTIONS
Kent Ramsay,
Abitibi-Consolidated
Q. Silicone-based
Defoamer deposits. Overdosing?
A. Repaired
agitator. Improved consistency control.
Ralph Lunn – Celgar
Pulp Co.
Q. Transport
of Dangerous Goods no longer requires “Residue” placarding: in fact, prohibits
it. What are mills doing to track full and empty railcars on the mill site?
A.
Checking spring heights
Check sheets
Howe Sound considered mill type
tagging
Q. What are
mills doing with their turpentine? Any methods to deal with a high sulphur
content?
A.
Tembec, Cariboo, Harmac all burn turpentine. Ft. Frances sells
to “Millenium”: they didn’t mind high sulphur levels sent to them. High sulphur
levels could be a result of poor temperature control (too cold).
Q.
Coating on D1 brightness probe?
A. Poor Eop washing could be contributing.
Oxidized manganese turn black. At Howe Soung, they tried moving the brightness
probe before the ClO2 addition; did not work. They then lowered the
D0 pH to 2.1 (from 2.5) and it helps a lot (acid washing)
Murray Walters, Pope
& Talbot- Harmac Pulp Operations
Q. Any mills having trouble keeping their
R8 generator density compensation working? – i.e. they plug.
A. Yes. Some mills have moved to nuclear
level transmitters. Must ensure signal lines are properly sloped. Jim Hopmnas
will send along latest Sterling standard.
Q. Anyone tried using renewal network
technology to infer [ClO3] and [H2SO4]?
A. Sterling put time into it at ??? but
didnt’ get anywhere. Their (Sterling) system currently uses “algorithms” that
function much the same.
Alex Edwards – Celgar Pulp
Q. Slime Control in pulp at Celgar.
A. Brian Gartley of Espanola, stated he
has some and control with biocide. Celgar believes that the constant S02
addition 6kg/hr. neutralizes all ClO2 in whitewater promotes slime.
Q. Control of liquid SO2 at low
flows (15ml/min) for souring ClO2. Does anyone tank it as H2SO3
and control to process using ORP? Currently using SO2 vaporizer on
Rail Car. Project to go to liquid SO2 and small tank.
A. Conductivity control/pH control
Can use straight injection @20kg/hr
Can use a tank at “x” concentration
Many types of controls, no one is
using ORP feedback control
Q.
SVP lite generator high solids: Does anyone hydraulically
doctor the solids off or use a shower/knock-off below the doctor blade to
control solids.
A.
Sterling has a retrofit hydraulic doctor which replaces
titanium doctor blade. DMI has installed a high pressure shower far below the
existing doctor blade. Talk to Jim Hoppman.
Kari Rae and Gavin
Baxter – Tembec, Skookumchuck
Q.
Neutralization stage, what brightness do you run D1
to?
A.
Increase in ClO2 on D1 and decrease on D2.
Cannot measure ClO2 residual on D1. Measure only on
upflow.
One mill did a comparison with DnD
and DEoD and found the E2 stage was required.
Another mill ran their DnD to
different pH’s an would have preferred an Ep stage
Check previous meeting minutes:
question by Ted Tam
Q.
What are mills using for effluent neutralization and what pH
target do you run?
A. CO2, pH= 9.8; Domtar,
Espanola – NaOH - pH 8.5-9.0; Celgar - NaOH - pH= 7.5; Alpac - NaOH - pH= 6.0;
St. Anne - nothing - pH = 6.5; Harmac – pH 7.0; Domtar – pH 8.5-9.0; Some mills
use CO2
Q.
Looking at glued or straped bale. Who are doing what? What
problems do they see?
A. Canfor Intercon - Glued domestic not
good for international.
Harmac- looking at
ball straped & glued.
Domtar have two mills on glued
bales.
Gerry Pageau - Howe Sound Pulp & Paper
Limited Partnership.
Q. ECF D0 stage control on comp.
brightness not working as well. Exit Bright strategy in question, Eo kappa too
low to measure easily. How are others handling Do
stage control?
A. Sounds like most still use comp bright.
Those on Kappa analyser KF control sound happiest.
Do inlet kappa for KF and Do
exit kappa and /or Eop exit kappa for feedback. Important to stabilize
brownstock washing carryover for this.
Q.
Getting only 90.5 % efficiency on R8 generator. What are
people doing to maximize efficiency?
A. Chorate mass flow meter with temp
correction, PAPRICAN ALEC level control and FTNIR sensor (from Kvaerner
Chemetics?). Level control is crucial as is control of acid and chlorate.
Minimizing rate changes helps a lot as does eliminating standby operation.
Guy Normandeau - DMI Peace River
Q. R8 control: Automate Acid Flow with
Temperature?
A. Canfor Intercon is using FTNIR to
control acid and chlorate addition.
Gordon Matson - Celgar
Q Bleach tower brick lining system- Any
satisfactory systems?
A. Not aware of a better system. Repairs
beginning at 5 years.
Laurier Morissette - BTG Americas
Q.
How to measure chlorite, lab titration is not repeatable.
A.
Paprican: use of IC chromatograph.
Alain Bergeron - Kruger
Q.
Does someone operate an Andritz MC pump at a consistency of 12
to 14%?
A.
Steve Bull/Tembec – operates its MC pump at 14%.
Michel Aucoin - Cascades FjordCell
Q. Our slaker is very limited in retention
time. For short term, we need to increase our green liquor TTA. What is your
TTA target and what is the TTA max. without affecting efficiency and scaling
problems?
A. 125-130 TTA – Alpac (Over 130- scaling
problems); 124 – Howe Sound; 125 – Wayagamack; 126 - Fort Frances
Q. Does anybody know a way (on-line or not)
to measure hydrated lime into white liquor?
A. No answer
recorded.
Brian Gartley -
Domtar Espanola
Q.
Biosulphate as an antichlor
- any issues with pulp quality as a
result.
A.
No impact; DMI Peace River –
photoactive; Halsey – used for peroxide residual. Drops pH and causes pitch
deposition; Check with Thurso and Cornwall; Peroxide may not work – pH
dependent
Q.
Neutralization of small ClO2
spills?
A.
Sterling – black earth and
sawdust, thio, any organic with ClO2 uptake. Pope & Talbot –
Bobcat with brownstock
Azim Shariff -
Domtar, Inc.
Q. Domtar
Woodland-(mixed northern HW market pulp) has determined that the lowest-cost bleaching
is the a D0 pH of 3:5. Any explanation?
A. Poor
washing on the D0 stage consumes
caustic in the E1 stage
Gerry
Pageau HSPP had similar situation until they improved washing on the D0 stage and have gone to a lower D0 stage = 2.5.
Q, Domtar
Windsor is looking for ways to reduce cadmium concentrations in bleach plant
filtrates so they can meet MEF limit of 10 ppm Cd in land application sludge.
A.
Raise D0 pH to minimize desorption in the bleach plant. No
literature, do lab trials (P. Earl). Dow will check bonding efficiency
of Cd to chelating agents. ( Irene Yaraskavitch, Dow) but thinks that it won’t
be as strong as Mn.
Q.
For mill on on/off AQ
usage, have they found any effect on pulp bleachability, viscosity, etc?
A.
Cariboo does on/off but see no difference in bleachability.
Intercon uses AQ continuously, have seen ½ kg/ton increase in ClO2.
Paprican lab studies seen an increase in chemical demand. Hypothesis is that
more “hemis” are retained and hemis are more difficult to bleach.
Ralph MacDonald - ALPAC
Q.
D0 pH targets before/after ClO2
addition. What observations have been noted at high or low pH? What impact on
ClO2 efficiency?
A.
Referred to ECF best practices, Grande Prairie meeting.
Bob Montgomery - Celgar
Q.
Salt Cake filter drum undersized
A.
Sterling are developing a washer shower bar – talk to DMI
(Drum out of round).
Q.
O2 delignification stock line vibrates. Could it be
pulp slip stick.
A.
Yes.