Tailoring Fiber Properties With Oxygen and Peroxide Beyond - - PowerPoint PPT Presentation

Tailoring Fiber Properties With Oxygen and Peroxide Beyond Brightness

Dongcheng Zhang, Dongho Kim, Lenong Allison, Zheng Dang, Arthur J. Ragauskas Institute of Paper Science and Technology School of Chemistry and Biochemistry Georgia Institute of Technology

Tailoring Fiber Properties – Beyond Brightness: Basic Realities of New Millennium

The Ruthless have the Edge Morgan Witzel, Financial Times

• “Eventually there comes a time when a company’s core market can

grow no further……..Share price begins to slip as investors seek better opportunities elsewhere

• Only three means of getting out of the saturation trap
• Aggressive method: Compete intensively with rivals, taking

market share away from competitors

• Acquisition method: Buy or merge companies
• Innovative method: Discover a new way to break of the

market and develop a new market

“If you want to succeed, you should strike out on new paths rather than travel the worn paths of accepted success.” – John D. Rockefeller Process Research Publications: +150,000 Product-Platform Research Publications: ~9,000

Tailoring Fiber Properties – Beyond Brightness: Promising Research Patterns

• Main group responsible for surface and bulk charge of

kraft fibers.

• Important for pulp swelling.
• Increase pulp fiber softness and collapsibility.
• Improve pulp strength properties.
• Improve beatability.
• Capable of ion-exchange reactions.

Tailoring Fiber Properties – Beyond Brightness: Importance of Carboxylate Groups

COO OOC COO COO COOH HOOC

[-COOH] Kspecific = [-COO ][H ]

The Fate of Fiber Charge:

Topochemistry of Acid Groups -ECF SW Kraft Pulp

0.2 0.6 1 1 2 3 4 5 Position

BLANK BULK SURFACE Lumen

[-COO-] Experimental: Grafted acid groups on holocellulose, controlling topochemistry

SEM

Barzyk, Page, and Ragauskas (1996)

The Fate of Fiber Charge:

Topochemistry of Acid Groups -ECF SW Kraft Pulp

0.05 0.1 0.15 0.2 0.25 170 220 270 320 370 Light Scattering Coefficient (cm

2

/ g) BLANK BULK SURFACE

Scott- Bond (J)

Conclusion: Surface acid groups yield unique strength properties

The Fate of Fiber Charge:

Fiber Acid Groups: Key parameter to enhance fiber-fiber

bonding, swelling, wet-end chemical retention

1 2 3 4 5 170 220 270 320 370 Light Scattering Coefficient (cm2/ g) BLANK BULK SURFACE

Breaking Length (km) Light Scattering (cm2/g)

Barzyk, Page, and Ragauskas (1996)

C O– O

Attachment of CMC onto Kraft ECF Fiber (Lindstrom, 2000)

• pH 8, 0.05 M CaCO3, csc 2.5%, 120oC, 2h
• 1 – 4% charge

Current Pulp Mill Status

The Fate of Fiber Charge: Fiber Charge - Mill Status

0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08 K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( S W ( P S / A Q ) ) K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( S W ) K r a f t

• C

( E u c a l y p t u s ) K r a f t

• C

( S W ) S u l f i t e S u l f i t e K r a f t

• C

( S W p

• s

t

• D

2 ) Acid content (meq/gr)

0.005 0.01 0.015 0.02 0.025 0.03 0.035 Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-B Kraft-B Acid content (meq/gr)

Little, if any, control of Fiber charge 0.016 – 0.07 meq/gr Fiber resource only current control mechanism

50 55 60 65 70 75 80 85 90 95 100 R e f e r e n c e C

• k

B r

• w

n S t

• c

k O 2 F e e d O 2 W a s h e r M a t D M a t ( E O P ) M a t D 1 M a t ( R 1

• 3

) * D 1 T r a n s f e r ( R 1

• 3

) D 1 M a t ( R 4 ) * D 1 T r a n s f e r ( R 4 ) * Stage Tensile Inde 20 40 60 80 100 120 Acid Content, µ eq/g Tensile Index Bulk A cid

The Fate of Fiber Charge: Mill Status

• OD(EOP)D Mill Tensile Strength and

Bulk/Surface Acid Groups

peroxide

Gradual loss of acid groups due in part to degradation of lignin Finally P increases Brightness Strength-acid groups

Surface Acid groups x10

The Fate of Fiber Charge During Peroxide Bleaching and Oxygen Delignification

What Contributes to Fiber Charge Unbleached Kraft Pulps

• Lignin
• Polysaccharides

> Uronic Acids > Hexenuronic Acids > Oxidized Reducing Ends

ECF Bleached Pulps

• Polysaccharides

> Uronic Acids > Oxidized Reducing Ends > Oxidized Fragments??

• Oxidized Lignin Fragments ??

1um

The Fate of Fiber Charge During Peroxide Bleaching and Oxygen Delignification

O CH2OH OR OH OR OH O CH2OH OR OH OR O O CH2OH RO OR O- OH O CH2OH OR O OH O CH2OH OR O O

• RO-

O CH2OH OR HO COOH

O2/HO-

Polysaccharide Degradation

O HO O HOH2C OR OR O O- HOH2C OR OR OH O2 O OH O HOH2C OR OR O O- O HOH2C OR OR O O HOH2C OR OR HO-

• HOO-

HOOC COOH HOO- H+ O HOH2C OR OR COOH HO HO-

O

Polysaccharide Retention

Fate of Fiber Charge Peroxide Bleaching

Carboxylic acid groups content versus Peroxide Bleaching Time 9 9.2 9.4 9.6 9.8 10 10.2 10.4 10.6 10.8 11 20 40 60 80 100 120 140 160 180 200 H2O2 Bleaching Time (min.) Carboxylica acid content (meq/100go.d. pulp)

3% H2O2, 2% NaOH, 10% con. 3% H2O2, 2% NaOH, 5% con. 3% H2O2, 2% NaOH, 5% con. 0.3% DTPA

Provide new operating protocols to enhance Fiber Charge

Sheet Strength, Water Retention Properties via an advanced P-stage

The Fate of Fiber Charge: Peroxide-Stage

The Fate of Fiber Charge: Peroxide Stage

33 34 35 36 37 38 39 40 41 42 43 44 meq/kg pulp

ECF Pulp E EOP-70C EOP-105C EOP-0.5% MgSO4 EOP-0.1% MnSO4 EOP-0.1% FeSO4

1% H2O2, 1% NaOH

The Fate of Fiber Charge: Peroxide Stage

33 34 35 36 37 38 39 40 41 42 43 44 meq/kg pul

ECF Pulp E EOP (1% H2O2) EP (1% H2O2) EP-(1% H2O2/0.5% M gSO4) EP- (1% H2O2/0.1% FeSO4) EP (2% H2O2)

1% H2O2, 1% NaOH, 70oC

The Fate of Fiber Charge: Peroxide Stage

35 35.5 36 36.5 37 37.5 38 38.5 39 39.5 40

meq/kg pulp

ECF Pulp (E+P) 40C (E+P) 50C (E+P) 60C (E+P) 70C (E+P) 80C

The Fate of Fiber Charge: Peroxide Stage

+ 12% + 10% 46.00 H2O2 bleaching with 0.5% MgSO4 + 11% + 10% 45.40 H2O2 bleaching without MgSO4 37.00 Original(fully bleached pulp) Tear Index Tensile Index Carboxylic Acid Content (meq./kg O.D. pulp) Conditions of H2O2 Bleaching 1% H2O2, 2% NaOH, 80 oC, 1 h

Fate of Fiber Charge Oxygen Delignification

The Fate of Fiber Charge: O Delignification

10 20 30 40 50 60 50 60 70 80 90 100 110 120

Carboxylic acid, µmol/g fiber Reaction time, min

1.5% NaOH 2.5% NaOH 3.5% NaOH 640 kPa O2 800 kPa O2 960 kPa O2 85

• C

100

• C

115

• C

Kraft Pulps

20 40 60 80 100 120 140 160 180 200 220

Acid content Kappa number Time,min Acid, µmol/g,residual lignin

14 16 18 20 22 24 26 28 30

Kappa number

The Fate of Fiber Charge: O Delignification

10 20 30 40 50 60 85 90 95 100 105 110

Acid, µmol/g,fiber Time, min

640 kPa 800 kPa 969 kPa 10 20 30 40 50 60 10 15 20 25 30

Kappa number Time, min

640 kPa 800 kPa 960 kPa

10 20 30 40 50 60 10 15 20 25 30

Kappa number Time, min

85

100

115

Higher O2 Pressure Better Delignification Higher Temperature Better Delignification Holocellulose Pulp Higher O2 Pressure Some Benefit Holocellulose Pulp Higher Temperature Less Fiber Charge

10 20 30 40 50 60 85 90 95 100 105 110

Acid,µmol/g,fiber Time, min 85

• C

100

• C

115

• C

The Fate of Fiber Charge: O Delignification

14 16 18 20 22 24 26 28 30 30 40 50 60 70 80 90 100 110 120 130

Bulk pulp Holocellulose Residual lignin

Kappa number Acid, µmol/g, fiber or holocellulose

160 180 200 220 240 260 280 300 320 340 360 380 400

Acid, µmol/g, residual lignin

Tensile strength

2 4 6 8 10 12 34.82 38.64 55.40 Acid groups content in holocellulose,mmol/g Tensile index,N.m/g

• 1. 30 – 50% Delignification
• 2. Holocellulose

The Fate of Fiber Charge: O Delignification

Kraft SW pulp

OD pulp

Screened a Series of Carboxylic Acid Generating Catalysts:

• Compatible with O-Chemistry
• Maintained or improved O-Delignification
• No negative effect of cellulose D.P.

O O O OH HO OH Cellulose Cellulose Oxidant O O O OH HO OH Cellulose Cellulose O

The Fate of Fiber Charge: O Delignification

Selective Oxidation of Polysaccharides Catalyst: Ruthenium pyrochlore oxide (Bi2RuxO7-x) Reported by Arts et al to be good for monosaccharides only! Journal of Carbohydrate Chemistry 15 (1996) 317-29.

O HO HO OH OH MeO O HO H OH H OMe O O O HO

• O

OH O- OMe O O O

• O

O O OH OMe O- H O O-

Oxidant Fast Oxidant Slow Oxidant

The Fate of Fiber Charge: O Delignification

18.7 15.4 0.39 18.8 15.4 0.18

• 15.5

0.10 19.2 15.5 Viscosity/mPa.s Kappa # Catalyst %

Oxygen Delignified Pulp Properties

10% csc, 2.5% NaOH, 800 kPa O2,100 oC

0.0 0.1 0.2 0.3 0.4 20 30 40 50 60 70 80

Carboxylic acid, µmol/g,HoloPulp Catalyst, %

O-Catalyst for Fiber Charge Development!

The Fate of Fiber Charge: O Delignification

18.35 21.42 16 17 18 19 20 21 22 Tensile index (N.m/g) 44.82 61.79 Carboxylic acid, µmol/g Holopulp 0.0 0.1 0.2 0.3 0.4 0.5 20 30 40 50 60 70 80

Carboxylic acid, µmol/g,HoloPulp Catalyst, %

• 1. 0 – .18% Catalyst/O
• 2. Holocellulose

The Fate of Fiber Charge: O Delignification

44.8 67.02 80.04000000000001 60 65 70 75 80 85

Tensile strength Stretch

Carboxylic acid, µmol/g HoloPulp Tensile index,mN/g

2 3 4 5

Stretch,%

Impact of Fiber Charge on Physical Properties

Holocellulose PFI Refined 600 CSF Improved Charge – Improved Tensile Index

The Fate of Fiber Charge: O Delignification

44.8 67.02 80.04 6 7 8 9 10 11 12

Tensile stiffness Ultrasonic in Plane specific stiffness:longitudial Ultrasonic in Plane specific stiffness:shear

Carboxylic acid, µmol/g HoloPulp Stiffness,kN/mm

2 or km 2/sec 2

3.0 3.5 4.0 4.5 5.0

Shear,km

2/sec 2

Impact of Fiber Charge on Physical Properties

Holocellulose PFI Refined 600 CSF Improved Charge – Improved Stiffness

The Fate of Fiber Charge: O Delignification

0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 O * O * D O * D ( E O ) O * D ( E O ) D 1 O * D ( E O ) D 1 D 2 O * D ( E O ) D P Carboxylic acid, µmol/g fiber k.f.=0.18 k.f.=0.22 k.f.=0.26

2% Catalyst in O-stage

12% + 14% 42.2 O*D0(EOP)D1 35.1 OD0(EOP)D1 µmol/g fiber Tensile Stiffness Tensile Index Carboxylic acid

Tailoring Fiber Properties With Oxygen and Peroxide Beyond Brightness Concluding Remarks

Tailoring Fiber Properties With Oxygen and Peroxide Beyond Brightness

• A modern pulp mill has little, if any, control over fiber

charge or oxycellulose content

• Surface charge is preferred but increases in bulk are also

beneficial with respect to strength properties

• Improvements in fiber charge are possible via current

bleaching protocols both in P and O

• First demonstrated application of catalyst for fiber charge

in O-stage, other O/P catalyst being pursued

• More innovative research is needed!

Tailoring Fiber Properties The Future

Starting Pulp Strength

Tailored Pulps For Strength Printing Water Absorption Refining Softness

Acknowledgments

DOE IPST@GT Research Consortium/Fellowship