Papers by Md Sarwar Jahan
Hemicellulose Removal from Hardwood Chips in the Pre-Hydrolysis Step of the Kraft-Based Dissolving Pulp Production Process
Http Dx Doi Org 10 1080 02773810903419227, Feb 23, 2010
... C for birch. REFERENCES 1. Sixta, H. Handbook of Pulp; WILEY-VCH Verlag GmbH &amp... more ... C for birch. REFERENCES 1. Sixta, H. Handbook of Pulp; WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim, Germany, 2006. 2. Linko, M.; Vikari, L.; Suihko, ML. Hydrolysis of xylan and fermentation of xylose to ethanol. Biotech Advs., 1984, 2, 233252. ...
Cellulose Chemistry and Technology, 2006
Milled wood lignins from four different ages of nalita and aspen wood were isolated and character... more Milled wood lignins from four different ages of nalita and aspen wood were isolated and characterized by UV, FT-IR, 1 H and 13 C NMR spectroscopy. Elemental composition, methoxyl analysis, molecular weight and alkaline nitrobenzene oxidation of the isolated lignin have been also studied. The C 9 formula for 30 month-old nalita was C 9 H 9.11 O 3.97 (OCH 3 ) 1.36, while that of aspen was C 9 H 8.93 O 3.50 (OCH 3 ) 1.52 . The alkaline nitrobenzene oxidation products showed a syringyl to guaiacyl ratio of nalita and aspen lignin of 1.6-1.8 and 3.0, respectively. The weight average molecular weight of nalita lignin was higher than that of aspen lignin. The polydispersity of nalita lignin decreased with tree age. 1 H NMR study of nalita MWL showed that the β-O-4 structural linkage increases with tree age. Nalita and aspen MWLs contained both erythro and threo configuration, although the erythro proton evidences a stronger peak.
Papermaking from Jute: A Win-Win Solution for Bangladesh
Bleaching and beating of soda-additive pulps from unretted whole jute plant (Corchorus capsularies)
Bangladesh Journal of Scientific and Industrial Research, 1999
Evaluation of additive in soda pulping of jute
Tappi Journal, 2001
Changes of paper properties of non-wood pulp on recycling
Tappi Journal, 2003
Effects of pulping processes on the fiber dimension of jute and whole jute plant pulps
Bioresource Technology, Feb 28, 2006
The chemical, morphological and anatomical studies of golpata fronds have been discussed. The lig... more The chemical, morphological and anatomical studies of golpata fronds have been discussed. The lignin, pentosan and a-cellulose in golpata fronds were comparable to some common nonwood and hardwood raw materials. The alkali, water and dichloromethane solubility were higher than wood and common nonwood. The fiber length 1.73 mm was observed, which is little bit shorter than softwood and longer than hardwood but fiber diameter was very short. The pulpability of golpata fronds has also been studied. The pulp yield was very low and Kappa number was high. The strength properties were better than that of some common nonwood pulps. FT-IR spectrum and alkaline nitrobenzene oxidation products showed that golpata fronds lignin mainly consist of syringyl (S) and guaiacyl units (V).
Formic acid/acetic acid pulping of kash (Saccharum spontaneum), jute (chorcorus capsularies) and dhaincha (Sesbania aculeata)
Ippta Quarterly Journal of Indian Pulp and Paper Technical Association, 2007
Pulping of Dhaincha (Sesbania aculeata)
Cellulose Chemistry and Technology, 2007
Soda-amine pulping of cotton stalk
Bangladesh Journal of Scientific and Industrial Research, 2000
Bleaching of different sapwood pulps using enzymes from a thermophillic fungus
Bangladesh Journal of Scientific and Industrial Research, 2000
Fiber dimensions and chemical properties of various nonwood materials and their suitability for paper production
Fiber dimensions, their derived values and chemical properties of cotton stalks (Gosypium hirsutu... more Fiber dimensions, their derived values and chemical properties of cotton stalks (Gosypium hirsutum L), jute stick (Corchorus capsularis) and dhancha (Sesbania aculeate) have been examined to assess their suitability for paper production. Cotton stalks have a good derived values ...
Effect of tree age on the soda-anthraquinone pulping of Nalita wood (Trema orientalis)
Journal of Industrial and Engineering Chemistry, 2004
Investigation on Soda and soda-AQ pulping of Saccharum spontaneum
Bangladesh Journal of Scientific and Industrial Research, 2004
Kraft pulping of cotton stalks has been done using 18, 20 and 22 Vo actle alkali in 18, 28 and 35... more Kraft pulping of cotton stalks has been done using 18, 20 and 22 Vo actle alkali in 18, 28 and 35 7o sulphidity. Pulp yield and kappa numbers were decreased with increasing active alkali. The pulping selectivity was increased with increasing sulphidity, hence higher pulp yield was observed in higher sulphidity. An addition of 0.1 vo AQin low sulphidity kraft liquor increased pulp yield to 43.1 vo with kappa number 25.3 whereas, without AQ, pulp yield was 42.9 vo with kappa number 26.1 in high sulphidity. The breaking lengttr, burst index and tear index were increased with increasing sulphidity. Low sulphidity kraft-Ae process exceeded the papermaking properties of high sulphidity kraft process.
Using precipitated calcium carbonate (PCC) as an alkali source in D1 and D2 brightening of a hardwood kraft pulp
Appita Journal, 2010
ABSTRACT An alkali source is needed to control the final pH of D1 and D2 stages in a conventional... more ABSTRACT An alkali source is needed to control the final pH of D1 and D2 stages in a conventional elemental chlorine free (ECF) chem. pulp bleaching sequence. This study evaluated the use of pptd. calcium carbonate (PCC) as an alternative alkali to caustic soda (NaOH) in the ClO2 brightening of a hardwood kraft pulp. The PCC-based process showed improved brightening performance over the conventional NaOH-based process due to its lower initial pH and flat overall pH profile in the system. The pulp viscosity was also better than that of the control pulp. The PCC-based process can save up to 0.2% ClO2 in achieving the same target brightness as the control. PCC was also evaluated as the alk. source for the alk. extn. stage and the results showed that the final pulp brightness decreased but the COD in the effluent also decreased. However, at a 20% PCC substitution in the alk. extn. stage, with the combination of the PCC-based D1 and D2 stages, a fully bleached pulp with higher final brightness, less brightness reversion and better viscosity than the control can be produced. [on SciFinder(R)]
TURKISH JOURNAL OF AGRICULTURE AND FORESTRY, 2013
In order to lower bleaching costs, various prebleaching methods have been investigated. In the cu... more In order to lower bleaching costs, various prebleaching methods have been investigated. In the current work 3 prebleaching methods, peroxyformic acid, oxygen, and xylanase, were investigated in bamboo and hardwood kraft pulp produced by Kharnaphuli Paper Mills. Among these 3 methods, peroxyformic acid showed the most promising results. Peroxyformic acid prebleaching reduced kappa numbers by 38% and 30% and increased brightness by 12.2% and 8.6% in hardwood and bamboo pulp, respectively. Using 30 kg ClO 2 t -1 of pulp, hardwood pulp attained 77.2% brightness, while peroxyformic-acid-prebleached pulp attained 86% brightness without a reduction in viscosity in D 0 E p D 1 bleaching sequences. To achieve 80% brightness, peroxyformic acid prebleaching saved 33% ClO 2 , while oxygen prebleaching saved 17% ClO 2 . Xylanase prebleaching was not an efficient method for these pulps. Bamboo pulp showed lower bleachability than hardwood pulp. The papermaking properties of the bleached pulps did not show significant variation after prebleaching, with the exception of tear index in peroxyformic-acid-prebleached pulp. When considering bleachability and papermaking properties, peroxyformic acid was the best prebleaching option for reducing ClO 2 consumption.
BioResources, 2013
Acetic acid is one of the major inhibitors of spent sulfite liquor (SSL) fermentation for ethanol... more Acetic acid is one of the major inhibitors of spent sulfite liquor (SSL) fermentation for ethanol production. The objective of this study was to remove acetic acid from hardwood SSL using anion exchange resin in order to achieve effective fermentation with Pichia stipitis CBS6054. Lignosulfonate, as well as sulfate and sulfite ions in the SSL hindered the removal of acetic acid by anion exchange resins. CaO treatment was an effective method for removing these materials from SSL, which facilitated the removal of acetic acid in the subsequent ion exchange resin treatment. A two-stage strong base ion exchange resin (OH form) treatment removed approximately 90% of the acetic acid from CaOtreated SSL, which decreased the acetic acid concentration to less than 1 g/L. The combined treatment of CaO and ion exchange resin treatments in a relatively short time achieved the selective removal of acetic acid from SSL and significantly increased the ethanol production from SSL.
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Papers by Md Sarwar Jahan