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Akhlesh Mathur - Global Market Segment Lead, Pulp
Edouard Valton - Senior Application Specialist, Pulp
Novel Cellulose-Based Detackifier for Efficient Pulp Mill Pitch Control
2
Agenda
Pitch in Wood
Traditional Pitch Control Program
Novel Cellulose-Based Detackifier
- Principle
- Mode of Action
- References
3
What is Pitch? Pitch is the collective term used to describe
the hydrophobic wood resin materials found in the pulp
Resin is a naturally occurring organic component of all trees
- functions as an energy storage source (fats) in tree and a defense mechanism against disease and insects
- typically occurs in ‘free flowing' resin canals (most softwoods and some tropical hardwoods) and as a storage inclusion in parenchyma cells (predominant resin source in most hardwoods)
- makes up (typically) 1 to 6% of the wood volume (DCM extract), with higher concentrations in the bark and the heartwood (especially in older trees)
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Pitch in Wood
Large part of the pitch is neutral (esters + sterols)
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Physical Forms of Pitch
Deposit
Agglomerate
Colloidal
Adsorbed ontofiber surface
Encapsulated
Na
Na-
-
-
-
Soluble / Soaps
Desirable Form
Minimize and
Control
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Pitch/Resin Entering the System
When pitch/resin enters the pulp making system, it takes one (or a combination) of the following routes: Carried with fibers causing dirt speck
- This undesirable path causes pitch problems in the downstream user systems.
Enters with water (black liquor)- This is the preferable route as it is easier to eliminate from the system
utilizing specialty chemicals.
Deposits on process equipment- This is undesirable since deposits within the system can cause
uncontrolled slough off causing dirt. This dirt can reduce process flow leading to process inefficiency and the need to clean the system requiring downtime.
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Chemical Program Options
Form Where to treat and wash or stabilize
Depositability DeTac™ contaminant control agents, surfactants
Free particle stability Anionic and non-ionic dispersants
Content Dispersants, fixatives and polymers
Surface affinity Surfactants and cleaners
Pitch Control Treatment
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Traditional Pitch Control
Pitch control in pulp mills is achieved by:
- Deresination - digester additive, wash aids, drainage aid
- Control of pitch deposit - avoid fouling
Traditional pitch control programs
- Talc (Mg3Si4O10(OH)2)
- Surfactant (ethoxylated material)
- Dispersant (anionic)
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Infinity™ PK7825E Pulp Processing Aid Novel Cellulose-Based Detackifier
Patented technology
Non-ionic – wide range of pH usage
Hydrophobic side groups enhance pitch coating and detackification
Effective talc replacement
Shear resistant
FDA and BfR approved
More effective than traditional detackifier
Pumpable
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Infinity PK7825E Pulp Processing Aid
No observed interference with pulp mill or bleach plant chemistries - Mill experience
Potential feed points- Temperature, pH and bleach chemistry tolerant
Infinity PK7825E Pulp Processing Aid Novel cellulose-based detackifier
Principle
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Infinity PK7825E Pulp Processing Aid:Principle
Product formerly developed for mechanical grades for P stage bleaching
Pitch content is not affected during peroxide stage
Pitch content during peroxide bleaching
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Electrolyte addition, mmol/L Electrolyte addition, mmol/L
Unbleached TMP Peroxide Bleached TMP
Infinity PK7825E Pulp Processing Aid:Principle Loss of hemicellulose during peroxide bleaching
destabilizes pitch (agglomeration)
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Infinity PK7825E Pulp Processing Aid:Principle Enhanced hemicellulose with greater pitch control
power
Infinity PK7825E pulp processing aid is used to compensate the lack of natural stabilizers
Benefits:- More stable pitch- Decreased agglomeration- Decreased deposition potential
Infinity PK7825E Pulp Processing Aid Novel cellulose-based detackifier
Mode of Action
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Infinity PK7825E Pulp Processing Aid : Mode of Action Hydrophobic interaction with pitch surfaces
Protective layer is used for detackification
HydrophobicHydrophilic
Protective Layer
+
HydrophobicPitch particle
Infinity PK7825E Pulp Processing Aid
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Encapsulation, Passivation, Detackification
Benefits:• Multiple attachment points• Internal film crosslinks• Tough hydrophilic film• Improved pitch controlHydrophobic
SegmentHydrophilic Segment
Pitch
Pitch Stabilizer
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Benefits
Detackification with Infinity PK7825E pulp processing aid is shear resistant
Impinging Jet Deposition During Stagnet Flow(Contract work by Aquantix, a unit of Alberta Research Council)
0
100
200
300
400
500
600
700
800
900
Untreated pitch Fixative Detac DC3970 DeTac 7225
Equal actives treatment
par
ticl
es /
mm
2d
epo
site
d o
n g
lass
su
rfac
e
5 min
90 min
Zero particles deposited up to 90 minutes
Impinging Jet Deposition During Stagnet Flow(Contract work by Aquantix, a unit of Alberta Research Council)
0
100
200
300
400
500
600
700
800
900
Untreated pitch Fixative Detac DC3970 DeTac 7225
Equal actives treatment
par
ticl
es /
mm
2d
epo
site
d o
n g
lass
su
rfac
e
5 min
90 min
Zero particles deposited up to 90 minutes
Infinity PK7825EPulp Processing Aid
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Benefits Eliminates talc feeding system
- Workforce cost
- Unit maintenance cost
- Increased safety (big bag handling, inhalation, slips, falls)
Decrease ClO2 consumption / OBA use Lower ash content in final pulp Wide range of pH (acid to alkaline) Behaves like fibers Fully approved formulation for food contact Non-hazardous chemical Easy to pump Detackification unchanged in high shear Temperature resistant
Infinity PK7825E Pulp Processing Aid Novel cellulose-based detackifier
References
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Mill A: Europe - HW Kraft Infinity PK7825E pulp
processing aid dosed to outlet of pre D2 filter- Prevents agglomeration
in D2 tower (reactor)
- Treated colloidal pitch is better washed away in D2 filter (VF6)
- Extractives retaining in pulp are treated and not agglomerating in HCST
Infinity PK4401 pulp processing aid is a fixative for colloidal balance control in white water system
D2
Hot water
Infinity PK4401 Pulp Processing Aid
30g/t
Intermediatechest
Filtered
waterVF5
VF6
HCST
Infinity PK7825E Pulp Processing Aid
250 g/t
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Infinity PK7825E pulp processing aid dosed to four points- VF3 outlet dose prevents
agglomeration in D2 tower (reactor)
- VF5 outlet dose keeps the pulp cleaners open
- Dose to showers on thickeners are to avoid periodical deposit formations and thereby to keep dirt count at low level (tgt <1.5 mm 2/kg) all the time
D2
Hot waterWarm water
VF3
VF5
Infinity PK7825E Pulp Processing Aid
Mill B: Europe - Integrated HW Kraft
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D2
Blow Tank
Brown stock
Storage Tower
Bleached Pulp
Storage Tower
D1
EOP
To paper machine
Infinity PK7825EPulp Processing Aid
300 g/t
Mill C: Europe - Kraft HWTalc Replacement
24
Mill D: US - Northeastern Sulfite Mill Species
- Hardwood
- Pine
Dosage- Trial Infinity PK7825 pulp processing aid at 1.1 kg/ton replacing 9 kg/ton of talc
- Product fed to E-Stage bleach washer discharge
Benefits - ClO2 usage reduced to reach target brightness with talc removed
- Talc usage eliminated
- OBA usage in paper mill reduced
25
Mill E: US - TMP Refiner
Species- Pine, hydrosulfite bleached
Production - 800 ADT/d integrated
Dosage- Infinity PK7825 pulp processing aid at 300g/ton replacing lignosulfonate
- Product fed before refiner
Benefits - Clean plate on refiner
- Minimal customer complaint regarding pitch
- Cost improvement
Thank you for your attention