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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. Lay-out of the presentation. Introduction
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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
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
Present scenario of Pulp and Paper Mill in Bangladesh Introduction } 26 paper mills based on recycled and imported pulp
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.
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
Chemical and morphological properties of trema orientalis Trema orientalis can substitute of short length fibrous raw material in pulp mill, which is needed for printing quality paper
Goal • Increased fiber yield for pulping • Increased pulp yield • Better bleaching
Cooking process Pulping • Soda • Soda-anthraquinone (AQ) • Kraft • Alkaline-sulfite-AQ-MeOH (ASAM) • Formic acid • Acetic acid
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.
Prebleaching • Oxygen • Xylanase • Peroxyacid
Effect of prebleaching in soda pulp O-oxygen, PFA-Peroxyformic acid, X-Xylanase
Bleaching • DED • QPP
DED and QPP bleaching of oxygen delignified different Trema orientalis pulps 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, %
DED bleaching of xylanase treated different Trema orientalis pulps 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, %
Comparison of DED bleaching between oxygen and xylanase delignified pulp
QPP bleaching of peroxyformic acid treated Trema orientalis pulps 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, %
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 10-50 % 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.