1. Evaluation of Cooking Processes for Trema orientalis (Nalita) Pulping
M Sarwar Jahan
Pulp and Paper Research Division, BCSIR Laboratories, Dhaka, Dr. Qudrat-I-Khuda Road, Dhaka-1205, Bangladesh
IUFRO ALL Division 5 Conference : Pulp and Paper B

2. Lay-out of the presentation
Introduction
Pulping of T. orientalis in different processes
Pre-bleaching of T. orientalis pulp in different processes
ECF and TCF bleaching
Conclusions

3. Present scenario of Pulp and Paper Mill in Bangladesh
Introduction
Present scenario of Pulp and Paper Mill in Bangladesh
Raw materials
Kharnaphuli Pulp and Paper Mills(KPM)
Kharnaphuli Rayon Mill
Sylhet Pulp and Paper Mills (SPPM)
North-Bengal Pulp and Paper Mills
Khulna Newsprient Mills
Gmelina arborea
Bamboo
Albizzia Moluccana Reeds
Bagasse
Gewa (Excoecaria agallocha) }
26 paper mills based on recycled and imported pulp

4. Allocated Forestland for KPM: 51,000 ha
Allocated Forestland for SPPM: 24,000 ha
Forestland in Bangladesh: 10.2 %
Population density: 1079/ Km2
It is almost impossible to increase forestland for industry. So we have to increase fiber yield using existing allocated forestland.

5. The most potential fast growing species in the environment of Bangladesh
Exotic species- Raintree (Samanea saman), Acacia spp., Eucalyptus spp.
Native species- Gmelina arborea,
A species named Trema orientalis has been found which has faster growth than any other species in Bangladesh

6. Trema orientalis garden

7. Cross section three years old Nalita stem

8. Chemical and morphological properties of trema orientalis
α-cellulose %
pentosan %
Lignin
Fiber length mm
48-50
22-23
20-24
0.83
Trema orientalis can substitute of short length fibrous raw material in pulp mill, which is needed for printing quality paper

9. Goal Increased fiber yield for pulping Increased pulp yield
Better bleaching

10. Pulping Cooking process Soda Soda-anthraquinone (AQ) Kraft
Alkaline-sulfite-AQ-MeOH (ASAM)
Formic acid
Acetic acid

11. Cooking conditions of different pulping processes
Soda
Soda-AQ
Kraft
ASAM
Acetic acid
Formic acid
AA, % as Na2O
AQ, %
Sulphidity, %
Methanol. % (v/v)
Na2SO3: NaOH
Acetic acid, %
Formic acid, %
Material : Liquor ratio
Temperature, oC
Time at max temp., min 17 -
1:4.5
170
120
0.1 30 20
80:20
180
90*
1:10
107 90
*0.2% HCl

12. Results of Trema orientalis pulping in different processes
Soda
Soda-AQ
Kraft
ASAM
Acetic acid
Formic acid
Screened yield, %
Reject, %
Total yield, %
Kappa number
Viscosity, mPa.s
44.8
0.2
45.0
20.8
15.5
45.9
46.1
18.4
16.6
45.3
45.5
10.8
13.4
51.7
1.1
52.8
30.4
56.0
39.1
21.8
55.9
34.1
15.7

13. Comparison of pulping processes relative to soda process

14. Evaluation of papermaking properties
In papermaking, it is common practice to refine/beat pulp for improving strength properties by mechanical treatment of fiber, which facilitates fiber bonding.

15. Beatability of different pulps of T. orientalis

16. SR number Vs tensile of trema orientalis pulp

17. SR number vs burst of trema orientalis pulp

18. SR number vs tear of trema orientalis pulp

19. SR number vs double fold no. of Trema orientalis pulps

20. Prebleaching
Oxygen
Xylanase
Peroxyacid

21. Effect of prebleaching in soda pulp
O-oxygen, PFA-Peroxyformic acid, X-Xylanase

22. Effect of prebleaching in soda-AQ pulp

23. Effect of prebleaching in kraft pulp

24. Effect of prebleaching in ASAM pulp

25. Bleaching
DED
QPP

26. DED and QPP bleaching of oxygen delignified different Trema orientalis pulps
oSR T TI BI
DFN D O B V
Soda DED
QPP
Soda-AQ DED QPP
Kraft DED QPP
ASAM DED QPP 42 41 43
37.7
38.5
42.2
39.1
31.7
34.4
48.5
42.5
6.6
5.8
8.4
8.5
7.9
8.8
10.6
10.5
3.1
3.2
3.7
3.0
4.9
4.3
114
128
111
252
175
698
674
0.512
0.519
0.564
0.549
0.547
0.570
0.534
0.578
87.6
87.9
87.4
86.6
88.1
86.7
88.8
83.7
79.8
74.6
76.0
73.2
80.9
77.3
86.1
79.1
10.1
12.4
11.9
10.3
13.1
13.4
T- Tensile index, N.m/g, TI-Tear index, mN.m2/g, BI- Burst index, kPa.m2/g DFN-Double fold number, D- Density, g/cc V-Viscosity, mPa.s, B- Brightness, %, O-Opacity, %

27. DED bleaching of xylanase treated different Trema orientalis pulps
oSR T TI BI
DFN D O B V
Soda
Soda-AQ
Kraft
ASAM 32 36 42 37
37.7
40.2
39.7
47.4
6.3
8.6
7.9
10.7
3.3
3.5
2.8
4.8 82
130
105
1250
0.502
0.549
0.602
0.587
86.8
87.3
86.9
86.7
80.1
76.6
82.9
88.6
10.8
11.9
11.1
15.8
T- Tensile index, N.m/g, TI-Tear index, mN.m2/g, BI- Burst index, kPa.m2/g DFN-Double fold number, D- Density, g/cc V-Viscosity, mPa.s, B- Brightness, %, O-Opacity, %

28. Comparison of DED bleaching between oxygen and xylanase delignified pulp

29. QPP bleaching of peroxyformic acid treated Trema orientalis pulps
oSR T TI BI
DFN D O B V
Soda
Soda-AQ
Kraft
ASAM
Formic acid
Acetic acid 36 35 37 45 51
35.4
38.2
38.5
41.9
19.4
27.4
5.1
4.7
9.9
10.9
6.4
4.3
1.6
2.0
2.1
4.0
1.9
1.0 11 12 39
465 8 6
0.550
0.585
0.575
0.551
0.470
0.352
88.3
88.6
82.8
81.7
89.2
87.3
73.7
71.7
78.8
83.0
75.2
10.8
12.3
18.0
11.6
4.9
T- Tensile index, N.m/g, TI-Tear index, mN.m2/g, BI- Burst index, kPa.m2/g DFN-Double fold number, D- Density, g/cc V-Viscosity, mPa.s, B- Brightness, %, O-Opacity, %

30. CONCLUSIONS
Trema orientalis is a high biomass producing, shorter length fiber tree for papermaking.
It is a brighter in appearance thus easier to bleach.
The ASAM process produced pulp of higher yield, lower kappa number, higher viscosity and initial brightness.
Prebleaching reduced kappa number by % depending on prebleaching treatment. Oxygen prebleaching reduced the highest kappa number. ASAM process showed the best and soda process showed the least results in oxygen treated DED and QPP bleaching.
Enzyme prebleached pulp gave better brightness in subsequent DED bleaching. ASAM process showed the best results in enzyme treated DED bleached pulp among the four processes.
Peroxyformic acid treated pulp responded very well in QPP bleaching. In this process, maximum brightness 83 % was attained in formic acid pulp, but strength properties were inferior.
Soda-AQ pulp responded poor bleachability.

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