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
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
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
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
The Fate of Fiber Charge: Topochemistry of Acid Groups -ECF SW Kraft Pulp Experimental: Grafted acid groups on holocellulose, controlling topochemistry [-C - ] 1 0.6 BLANK BULK SURFACE 0.2 1 2 3 4 5 Lumen Position SEM Barzyk, Page, and Ragauskas (1996)
The Fate of Fiber Charge: Topochemistry of Acid Groups -ECF SW Kraft Pulp Scott- Bond (J) 0.25 0.2 0.15 0.1 BLANK BULK SURFACE 0.05 0 170 220 270 320 370 Light Scattering Coefficient (cm 2 / g) 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 5 4 C Breaking Length (km) 3 2 1 0 170 220 270 320 370 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
Current Pulp Mill Status
The Fate of Fiber Charge: Fiber Charge - Mill Status 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0 0.035 0.03 0.025 0.02 0.015 0.01 0.005 0 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 0.016 0.07 meq/gr Fiber resource only current control mechanism
The Fate of Fiber Charge: Mill Status D(EP)D Mill Tensile Strength and Bulk/Surface Acid Groups Tensile Inde 100 95 90 85 80 75 70 65 60 55 Surface Acid groups x10 Tensile Index Bulk Acid peroxide 120 100 80 60 40 20 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
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??
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
Fate of Fiber Charge Peroxide Bleaching
The Fate of Fiber Charge: Peroxide-Stage Carboxylic acid groups content versus Peroxide Bleaching Time 11 Carboxylica acid content (meq/100go.d. pulp) 10.8 10.6 10.4 10.2 10 9.8 9.6 9.4 9.2 9 3% H22, 2% NaH, 10% con. 3% H22, 2% NaH, 5% con. 3% H22, 2% NaH, 5% con. 0.3% DTPA 0 20 40 60 80 100 120 140 160 180 200 H22 Bleaching Time (min.) 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 meq/kg pulp 44 43 42 41 40 39 38 37 36 35 34 33 1% H 2 2, 1% NaH ECF Pulp E EP-70C EP-105C EP-0.5% MgS4 EP-0.1% MnS4 EP-0.1% FeS4
The Fate of Fiber Charge: Peroxide Stage ECF Pulp meq/kg pul 44 43 42 41 40 39 38 37 36 35 34 33 1% 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)
The Fate of Fiber Charge: Peroxide Stage 40 39.5 39 38.5 meq/kg pulp 38 37.5 37 36.5 36 35.5 35 ECF Pulp (E+P) 40C (E+P) 50C (E+P) 60C (E+P) 70C (E+P) 80C
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) 37.00 H 2 2 bleaching without MgS 4 45.40 + 10% + 11% H 2 2 bleaching with 0.5% MgS 4 46.00 + 10% + 12%
Fate of Fiber Charge xygen Delignification
The Fate of Fiber Charge: Delignification 220 Acid content Kappa number 30 28 Acid, µmol/g,residual lignin 200 180 160 140 120 100 120 0 20 40 60 80 Time,min 110 26 24 22 20 18 16 14 Kappa number Kraft Pulps Carboxylic acid, µmol/g fiber 100 90 80 70 60 50 1.5% NaH 2.5% NaH 3.5% NaH 640 kpa 2 800 kpa 2 960 kpa 2 85 o C 100 o C 115 o C 0 10 20 30 40 50 60 Reaction time, min
The Fate of Fiber Charge: Delignification 30 640 kpa 800 kpa 960 kpa Higher 2 Pressure Better Delignification 30 85 0 C 100 0 C 115 0 C Kappa number 25 20 Higher Temperature Better Delignification Kappa number 25 20 15 15 10 0 10 20 30 40 50 60 Time, min 10 0 10 20 30 40 50 60 Time, min 110 640 kpa 800 kpa 969 kpa 110 85 o C 100 o C 115 o C 105 105 Acid, µmol/g,fiber 100 95 Holocellulose Pulp Higher 2 Pressure Some Benefit Acid,µmol/g,fiber 100 95 90 85 0 10 20 30 40 50 60 Time, min Holocellulose Pulp Higher Temperature Less Fiber Charge 90 85 0 10 20 30 40 50 60 Time, min
The Fate of Fiber Charge: Delignification Acid, µmol/g, fiber or holocellulose 130 120 110 100 90 80 70 60 50 40 Bulk pulp Holocellulose Residual lignin 30 14 16 18 20 22 24 26 28 30 Kappa number 400 380 360 340 320 300 280 260 240 220 200 180 160 Acid, µmol/g, residual lignin 1. 30 50% Delignification 2. Holocellulose Tensile strength 12 Tensile index,n.m/g 10 8 6 4 2 0 34.82 38.64 55.40 Acid groups content in holocellulose,mmol/g
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
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) 317-29.
The Fate of Fiber Charge: Delignification xygen Delignified Pulp Properties Catalyst % Kappa # Viscosity/mPa.s 0 15.5 19.2 80 0.10 15.5-0.18 15.4 18.8 0.39 15.4 18.7 10% csc, 2.5% NaH, 800 kpa 2,100 o C Carboxylic acid, µmol/g,holopulp 70 60 50 40 30 -Catalyst for Fiber Charge Development! 20 0.0 0.1 0.2 0.3 0.4 Catalyst, %
The Fate of Fiber Charge: Delignification 80 1. 0.18% Catalyst/ Carboxylic acid, µmol/g,holopulp 70 60 50 40 30 2. Holocellulose 20 0.0 0.1 0.2 0.3 0.4 0.5 Catalyst, % 22 21 21.42 Tensile index (N.m/g) 20 19 18 17 16 18.35 44.82 61.79 Carboxylic acid, µmol/g Holopulp
The Fate of Fiber Charge: Delignification Impact of Fiber Charge on Physical Properties 85 Tensile strength Stretch 5 80 Tensile index,mn/g 75 70 65 4 3 Stretch,% 60 44.8 67.02 80.04000000000001 Carboxylic acid, µmol/g HoloPulp 2 Holocellulose PFI Refined 600 CSF Improved Charge Improved Tensile Index
The Fate of Fiber Charge: Delignification Impact of Fiber Charge on Physical Properties 12 11 Tensile stiffness Ultrasonic in Plane specific stiffness:longitudial Ultrasonic in Plane specific stiffness:shear 5.0 Stiffness,kN/mm 2 or km 2 /sec 2 10 9 8 7 6 4.5 4.0 3.5 Shear,km 2 /sec 2 44.8 67.02 80.04 Carboxylic acid, µmol/g HoloPulp 3.0 Holocellulose PFI Refined 600 CSF Improved Charge Improved Stiffness
The Fate of Fiber Charge: Delignification Carboxylic acid Tensile Index Tensile Stiffness µmol/g fiber Carboxylic acid, µmol/g fiber 140.00 120.00 100.00 80.00 60.00 40.00 20.00 D 0 (E P )D 1 35.1 *D 0 (E P )D 1 42.2 + 14% k.f.=0.18 k.f.=0.22 k.f.=0.26 12% 0.00 * *D0 2% Catalyst in -stage *D0(E) *D0(E)D1 *D0(E)D1D2 *D0(E)DP
Tailoring Fiber Properties With xygen and Peroxide Beyond Brightness Concluding Remarks
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!
Tailoring Fiber Properties The Future Pulp Strength Starting Tailored Pulps For Strength Printing Water Absorption Refining Softness
Acknowledgments DE IPST@GT Research Consortium/Fellowship