Tailoring Fiber Properties With Oxygen and Peroxide Beyond Brightness

Transcription

1 Tailoring Fiber Properties With xygen 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

2 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 nly 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

3 Tailoring Fiber Properties Beyond Brightness: Promising Research Patterns 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

4 Tailoring Fiber Properties Beyond Brightness: Importance of Carboxylate Groups Main group responsible for surface and bulk charge of kraft fibers. C Important for pulp swelling. Increase pulp fiber softness and collapsibility. Improve pulp strength properties. Improve beatability. HC Capable of ion-exchange reactions. C C K specific = [-C ][H ] [-CH] C CH

5 The Fate of Fiber Charge: Topochemistry of Acid Groups -ECF SW Kraft Pulp Experimental: Grafted acid groups on holocellulose, controlling topochemistry [-C - ] BLANK BULK SURFACE Lumen Position SEM Barzyk, Page, and Ragauskas (1996)

6 The Fate of Fiber Charge: Topochemistry of Acid Groups -ECF SW Kraft Pulp Scott- Bond (J) BLANK BULK SURFACE Light Scattering Coefficient (cm 2 / g) Conclusion: Surface acid groups yield unique strength properties

7 The Fate of Fiber Charge: Fiber Acid Groups: Key parameter to enhance fiber-fiber bonding, swelling, wet-end chemical retention 5 4 C Breaking Length (km) Light Scattering Coefficient (cm 2 / g) Light Scattering (cm 2 /g) BLANK BULK SURFACE Barzyk, Page, and Ragauskas (1996) Attachment of CMC onto Kraft ECF Fiber (Lindstrom, 2000) - ph 8, 0.05 M CaC 3, csc 2.5%, 120 o C, 2h - 1 4% charge

8 Current Pulp Mill Status

9 The Fate of Fiber Charge: Fiber Charge - Mill Status Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-A Kraft-B Kraft-B Acid content (meq/gr) Kraft-C (SW) Kraft-C (SW) Kraft-C (SW (PS/AQ)) Kraft-C (SW) Kraft-C (SW) Kraft-C (SW) Kraft-C (Eucalyptus) Kraft-C (SW) Sulfite Sulfite Kraft-C (SW post-d2) Acid content (meq/gr) Little, if any, control of Fiber charge meq/gr Fiber resource only current control mechanism

10 The Fate of Fiber Charge: Mill Status D(EP)D Mill Tensile Strength and Bulk/Surface Acid Groups Tensile Inde Surface Acid groups x10 Tensile Index Bulk Acid peroxide Acid Content, µeq/g Gradual loss of acid groups due in part to degradation of lignin 50 Reference Cook Brown Stock 2 Feed 2 Washer Mat Stage D0 Mat (EP) Mat D1 Mat (R1-3)* D1 Transfer (R1-3) D1 Mat (R4)* D1 Transfer (R4)* 0 Finally P increases Brightness Strength-acid groups

11 The Fate of Fiber Charge During Peroxide Bleaching and xygen Delignification What Contributes to Fiber Charge Unbleached Kraft Pulps - Lignin - Polysaccharides > Uronic Acids > Hexenuronic Acids > xidized Reducing Ends ECF Bleached Pulps 1um - Polysaccharides > Uronic Acids > xidized Reducing Ends > xidized Fragments?? - xidized Lignin Fragments??

12 The Fate of Fiber Charge During Peroxide Bleaching and xygen Delignification Polysaccharide Degradation CH 2 H CH 2 H CH 2 H R 2 /H - R R H H R R R H H - - R- Polysaccharide Retention HH 2 C R H R HH 2 C R H R - 2 HH 2 C CH 2 H R CH 2 H R CH 2 H R H - R H R - H CH H -H - HH 2 C R H - HH 2 C R R H + R HC CH H - HH 2 C R R H CH

13 Fate of Fiber Charge Peroxide Bleaching

14 The Fate of Fiber Charge: Peroxide-Stage Carboxylic acid groups content versus Peroxide Bleaching Time 11 Carboxylica acid content (meq/100go.d. pulp) % H22, 2% NaH, 10% con. 3% H22, 2% NaH, 5% con. 3% H22, 2% NaH, 5% con. 0.3% DTPA H22 Bleaching Time (min.) Provide new operating protocols to enhance Fiber Charge Sheet Strength, Water Retention Properties via an advanced P-stage

15 The Fate of Fiber Charge: Peroxide Stage meq/kg pulp % H 2 2, 1% NaH ECF Pulp E EP-70C EP-105C EP-0.5% MgS4 EP-0.1% MnS4 EP-0.1% FeS4

16 The Fate of Fiber Charge: Peroxide Stage ECF Pulp meq/kg pul % H 2 2, 1% NaH, 70 o C E EP (1% H22) EP (1% H22) EP-(1% H22/0.5% MgS4) EP- (1% H22/0.1% FeS4) EP (2% H22)

17 The Fate of Fiber Charge: Peroxide Stage meq/kg pulp ECF Pulp (E+P) 40C (E+P) 50C (E+P) 60C (E+P) 70C (E+P) 80C

18 The Fate of Fiber Charge: Peroxide Stage 1% H 2 2, 2% NaH, 80 o C, 1 h Conditions of H 2 2 Bleaching Carboxylic Acid Content (meq./kg.d. pulp) Tensile Index Tear Index riginal(fully bleached pulp) H 2 2 bleaching without MgS % + 11% H 2 2 bleaching with 0.5% MgS % + 12%

19 Fate of Fiber Charge xygen Delignification

20 The Fate of Fiber Charge: Delignification 220 Acid content Kappa number Acid, µmol/g,residual lignin Time,min Kappa number Kraft Pulps Carboxylic acid, µmol/g fiber % NaH 2.5% NaH 3.5% NaH 640 kpa kpa kpa 2 85 o C 100 o C 115 o C Reaction time, min

21 The Fate of Fiber Charge: Delignification kpa 800 kpa 960 kpa Higher 2 Pressure Better Delignification C C C Kappa number Higher Temperature Better Delignification Kappa number Time, min Time, min kpa 800 kpa 969 kpa o C 100 o C 115 o C Acid, µmol/g,fiber Holocellulose Pulp Higher 2 Pressure Some Benefit Acid,µmol/g,fiber Time, min Holocellulose Pulp Higher Temperature Less Fiber Charge Time, min

22 The Fate of Fiber Charge: Delignification Acid, µmol/g, fiber or holocellulose Bulk pulp Holocellulose Residual lignin Kappa number Acid, µmol/g, residual lignin % Delignification 2. Holocellulose Tensile strength 12 Tensile index,n.m/g Acid groups content in holocellulose,mmol/g

23 The Fate of Fiber Charge: Delignification D pulp Kraft SW pulp Screened a Series of Carboxylic Acid Generating Catalysts: Cellulose Compatible with -Chemistry Maintained or improved -Delignification No negative effect of cellulose D.P. H H H Cellulose xidant Cellulose H H H Cellulose

24 The Fate of Fiber Charge: Delignification Selective xidation of Polysaccharides H H H H Me xidant H H H H xidant Slow H xidant Fast Me - - H Me - H H - - Me Catalyst: Ruthenium pyrochlore oxide (Bi 2 Ru x 7-x ) Reported by Arts et al to be good for monosaccharides only! Journal of Carbohydrate Chemistry 15 (1996)

25 The Fate of Fiber Charge: Delignification xygen Delignified Pulp Properties Catalyst % Kappa # Viscosity/mPa.s % csc, 2.5% NaH, 800 kpa 2,100 o C Carboxylic acid, µmol/g,holopulp Catalyst for Fiber Charge Development! Catalyst, %

26 The Fate of Fiber Charge: Delignification % Catalyst/ Carboxylic acid, µmol/g,holopulp Holocellulose Catalyst, % Tensile index (N.m/g) Carboxylic acid, µmol/g Holopulp

27 The Fate of Fiber Charge: Delignification Impact of Fiber Charge on Physical Properties 85 Tensile strength Stretch 5 80 Tensile index,mn/g Stretch,% Carboxylic acid, µmol/g HoloPulp 2 Holocellulose PFI Refined 600 CSF Improved Charge Improved Tensile Index

28 The Fate of Fiber Charge: Delignification Impact of Fiber Charge on Physical Properties Tensile stiffness Ultrasonic in Plane specific stiffness:longitudial Ultrasonic in Plane specific stiffness:shear 5.0 Stiffness,kN/mm 2 or km 2 /sec Shear,km 2 /sec Carboxylic acid, µmol/g HoloPulp 3.0 Holocellulose PFI Refined 600 CSF Improved Charge Improved Stiffness

29 The Fate of Fiber Charge: Delignification Carboxylic acid Tensile Index Tensile Stiffness µmol/g fiber Carboxylic acid, µmol/g fiber D 0 (E P )D *D 0 (E P )D % k.f.=0.18 k.f.=0.22 k.f.= % 0.00 * *D0 2% Catalyst in -stage *D0(E) *D0(E)D1 *D0(E)D1D2 *D0(E)DP

30 Tailoring Fiber Properties With xygen and Peroxide Beyond Brightness Concluding Remarks

31 Tailoring Fiber Properties With xygen 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 First demonstrated application of catalyst for fiber charge in -stage, other /P catalyst being pursued More innovative research is needed!

32 Tailoring Fiber Properties The Future Pulp Strength Starting Tailored Pulps For Strength Printing Water Absorption Refining Softness

33 Acknowledgments DE Research Consortium/Fellowship