S.Ahmad, R.Jain, R.Mediratta, K.D.Prasad, S.S.Arora Ballarpur Industries Ltd, Unit Shree Gopal IPPTA Seminar – Chandigar

1. Enzymatic treatment on chemical pulp in beating/refining process – An attempt towards energy conservation S.Ahmad, R.Jain, R.Mediratta, K.D.Prasad, S.S.Arora Ballarpur Industries Ltd, Unit Shree Gopal IPPTA Seminar – Chandigarh July 13-14th 2006

2. PAPER HIGHLIGHTS Enzymatic treatment on chemical pulp • Enzyme - Carbohydrase base • Lab study with unbleached and bleached pulps • Effect on freeness/drainage and strength properties. • Effect on beating time • Plant trial

3. INTRODUCTION • Pulp and paper industry in India is the sixth largest energy consumer in the industrial sector. • Energy costs account for about 25% of the total manufacturing cost. • Enzymatic technology can save about 30% of the energy consumed in refining during paper making process.

4. INTRODUCTION Enzymes • Theyare very large and complex protein molecules consisting of inter-twined chains of amino acids. • Special proteins found in all living matter • Natural Catalyst, Nontoxic and biodegradable • Each enzyme is specific to respective class of reaction

5. INTRODUCTION Carbohydrase(Cellulase/hemicellulase) • Enhances and restores fiber strength • Reduce refining energy requirements • Increases inter-fiber bonding fibrillation, while increasing drainage rates and avoiding fiber breakage

6. INTRODUCTION Mechanism of refining • Enhances fibrillation and inter- fiber bonding. • Increases the strength of fiber to fiber bonding. • Increases the bonding surface area and leads to denser sheet. • Individual fibers are made shorter due to cutting action.

7. INTRODUCTION Mechanism of enzyme treatment • Helps to soften the fiber walls and increases access to the cellulose • Helps in breaking up the primary wall which is thin (0.05 micron thick) • Helps peeling process of S1 layer. • Fibers becomes easier to refine. • Enzyme helps to digest small fractions while reducing fines.

8. INTRODUCTION Chemical nature and processing condition • Chemical composition : Liquid neutral cellulase/hemicellulase (carbohydrase enzyme) • Dose : 0.05-0.2 kg/MT of OD pulp • pH range : 5.5-7.3 • Retention Time : 1 to 2 hrs • Temperature : 30 to 60°C

9. LAB STUDY

10. EXPERIMENTAL APPROACH Objective A. Effect on freeness/drainage and strength properties B. Effect on beating time Enzyme Two different enzymes(Carbohydrase base)from two different suppliers. • Enzyme-1 • Enzyme-2

11. EXPERIMENTAL APPROACH Pulp characteristics Unbleached pulp* Kappa no. : 18.0 Viscosity : 20.0 cps Bleached pulp* Brightness ISO : +89% Viscosity : 10.0 cps Fiber length : 0.5 to 3.5 Avg. 1.2 mm *Mixed hardwood : 84% Bamboo : 16%

12. EXPERIMENTAL APPROACH Enzyme condition in lab Enzyme Dose : 200gm/MT of OD pulp Consistency : 5.0% Temperature : 50°C Retention time : 60 min pH : 6.6-6.9

13. EXPERIMENTAL APPROACH Pulp after enzyme treatment • Bleached pulp • Viscosity : 9.8 cps • Microscopic study : Swelling Untreated pulp(4x) Enzyme treated pulp(4x)

14. EXPERIMENTAL APPROACH A.Effect on freeness/drainage & strength properties –Unbleached pulp

15. EXPERIMENTAL APPROACH A.Effect on freeness/drainage & strength properties –Bleached pulp

16. EXPERIMENTAL APPROACH B.Effect on beating time – Unbleached pulp

17. EXPERIMENTAL APPROACH B.Effect on beating time – Bleached pulp

18. EXPERIMENTAL APPROACH Effect on freeness/drainage & strength properties -Unbleached Effect on freeness (°SR) Effect on breaking length

19. EXPERIMENTAL APPROACH Effect on freeness/drainage & strength properties -Bleached Effect on freeness (°SR) Effect on breaking length

20. EXPERIMENTAL APPROACH Effect on beating time Unbleached pulp Bleached pulp

21. EXPERIMENTAL APPROACH Observations • Effect on freeness/drainage & strength properties • Enzyme performs better in bleached pulp. • Enzyme-2 performed better than enzyme-1. • Freeness value increased max 5 point in bleached pulp with Enzyme- 2. • Breaking length of bleached pulp hand sheets increased from 6680 to 6950 meter with the application of Enzyme-2.

22. EXPERIMENTAL APPROACH Observations • Effect on beating time • Beating time of unbleached pulp reduced from 35 to 32 & 30 min. with enzyme 1 & 2 respectively. • With the bleached pulp, Beating time reduced from 35 to 30 & 27 min. with enzyme 1 & 2 respectively. Higher reduction in beating time with enzyme-2

23. PLANT TRIAL

24. PLANT TRIAL Objective • To reduce energy consumption in refining • To maintain same strength properties

25. PLANT TRIAL • Selection of enzyme • Enzyme-2 • Enzyme condition Enzyme Dose : 50gm/MT of OD pulp Optimized on 30gm/MT Consistency : 3.5% Temperature : 35°C Retention time : 120 min pH : 6.7-6.8

26. PLANT TRIAL Paper machine no. 4 • Machine specifications Make : Esser Wyss Type : MF with size press & kuster calendar Speed : 350 m/min. Grammage : 54-80 g/m² Deckle : 3.15 m

27. PLANT TRIAL Dosing point : Buffer chest before refining Paper roll Head box Size press

28. PLANT TRIAL Wet end condition

29. PLANT TRIAL Paper properties

30. PLANT TRIAL Effect on Power consumption in refiner process

31. PLANT TRIAL Calculations for power saving Case(I) Untreated pulp (control) Load at refiner : 27 amp Power consumed in refiner : 262.34 kWh Case(II) Treated pulp Load at refiner : 22 amp Power consumed in refiner : 213.76 kWh Power Saving : 48.58 kWh Power saving MT of paper : 13.9 kWh(Draw 3.5 MT/hr.) Power saving in Rs. per MT : Rs. 30.5 (at Rs. 2.2/kWh) Enzyme cost in Rs. per MT : Rs. 16.1 (@ Rs. 537/kg) Saving in Rs. per MT : Rs. 14.4

32. CONCLUSIONS Enzymatic Treatment on Chemical Pulp Lab Study Effect on freeness & strength Effect on beating time Increasing in freeness value up to 5 Point Increasing in Breaking length by 4.0% Decrease in beating time by 22.8% Plant Trial 18.5 % reduction in power Consumption in refiner

33. CONCLUSIONS • Enzyme performs better in bleached pulp as compared to unbleached pulp. • Freeness value(°SR) increased by 5 point. • Breaking length improved up to 4.0%. • Helpful wherever limitation in refining. • 18.5% energy saving during refining resulted in saving of Rs. 14.4 per MT. Conserving the natural resources: Energy conservation

34. THANK YOU