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Grasses have emerged as potential alternative raw materials which can replace wood for pulp and paper products. Various species of grasses have been explored previously for pulp and paper production. This study is aimed to investigate pulp and papermaking characteristics of a grass species namely Cymbopogon winterianus Jowitt which is commonly known as citronella grass. This grass was subjected to proximate chemical characterisation; fibre morphology analysis; soda, soda-AQ (soda-anthraquinone), and kraft pulping; elemental chlorine free bleaching using D0EPD1 (D = ClO2 in acidic medium; EP = alkaline extraction with addition of H2O2; 0 and 1 = initial and final stage) sequence; and evaluation of physical strength properties of paper hand sheets. The pulp and paper hand sheets were also examined through SEM (scanning electron microscope) and FTIR (Fourier-transform infrared) spectroscopy to observe the structural and functional group variations. The proximate chemical analysis of citronella grass was found superior in terms of α-cellulose (38.10%), pentosans (22.30%) and alkali solubility (28.20%) while inferior in terms of ash (8.20%), lignin (25.10%) and alcohol benzene solubility (6.31%) with respect to some other grass species used for pulp and papermaking. Fibre length (0.69–0.74 mm) and fibre width (13.8–15.1 μm) were also comparable to other grass species. Brown pulp characteristics such as screened yield (44.67%), brightness (~24 %ISO) and kappa number (~20) revealed superiority of soda-AQ pulping among all the pulping processes while the kraft pulp exhibited the highest brightness (83.05 %ISO) and intrinsic viscosity (17.6 cP) after D0EPD1 bleaching. Tear index, tensile index and burst index of paper hand sheets obtained from bleaching of soda-AQ and kraft pulps were almost similar but higher to that of bleached soda pulp. The citronella grass was found suitable for producing writing and printing grade paper based on processes and optimised parameters described in this study. [ABSTRACT FROM AUTHOR]

More than 70 % bleached chemical pulp is produced in India through elemental chlorine-free bleaching in which chlorine-based compounds like chlorine dioxide is a dominant chemical which generates chlorinated organic toxins harmful to the environment. Present studies demonstrate short sequence of bleaching combined with acid treatment, followed by pressurized oxygen delignification. It was found that efficiency of oxygen improved by adding hydrogen peroxide as an additive in oxygen delignification with subsequent treatment with ozone or chlorine dioxide as bleaching agents. It was observed that by using additive in ODL process, pulp can achieve 70±1 (%ISO) brightness. Reduction attains in kappa number 65–70 % as compared to 45–50 % in control oxygen delignification stage. Through AOpZ and AOpD bleaching sequences, full brightness achieved 84–85 (%ISO) without considerable loss in mechanical strength properties compared to DEpD sequence. A potential reduction in COD, color, and AOX was 28, 53.3, and 88 % respectively were observed in AOpZ short bleaching sequence compared to DEpD bleaching. [ABSTRACT FROM AUTHOR]

Purpose: This investigation is aimed to explore the pulp and papermaking potential of solid residue left after isolation of essential oil from Cymbopogon winterianus Jowitt using hydro distillation, as well as to evaluate the physical strength properties of pulp and paper produced from it.Methods: Soda, soda–AQ (soda–anthraquinone) and kraft pulping of oil isolated C. winterianus were optimized and the corresponding optimum unbleached pulp in each process was subjected to environment friendly ECF (elemental chlorine free) bleaching using D1EpD2 (D = chlorine dioxide in acidic medium; Ep = alkaline extraction with addition of hydrogen peroxide; 1 and 2 = first and second time) sequence. Fibre morphological investigation and fibre classification of bleached pulp from every optimized pulping process were also carried out. Hand sheets of bleached pulps were prepared to evaluate the physical strength properties. All the methods were followed as per standard procedures.Results: The proximate chemical composition of oil isolated C. winterianus revealed 62.70% holocellulose, 37.62% alpha-cellulose, 21.10% pentosans and 24.10% lignin. Kraft pulping at 12% NaOH dose and 20% sulphidity produced unbleached pulp with kappa 18.72, yield 43.68%, brightness 21.36% and viscosity 32.6 cp; while bleached pulp with brightness 83.67% and viscosity 16.7 cp. However, hand sheets prepared from soda–AQ pulping exhibited tensile index 31.5 N m/g, tear index 5.02 m Nm2/g and burst index 2.20 kPam2/g which were superior to kraft pulping. Soda pulp demonstrated inferiority in quality to kraft and soda–AQ pulps. No significant differences were observed in fibre morphology of pulps from different processes while fibre classification revealed maximum useful bleached fibres 55.9% from kraft pulping.Conclusions: This research proved that C. winterianus solid residue left after isolation of essential oil could be a substantial source for pulp and papermaking using conventional pulping processes and ECF bleaching sequence at process conditions described in this work. [ABSTRACT FROM AUTHOR]

Pulp and paper industry use different chemicals to separate cellulose fibre from lignocellulosic biomass for papermaking. The use of sodium sulphide and chlorine during pulping and bleaching processes, have now been classified as the main sources of air and water pollution in the pulp and paper industry. To surmount these problems biological processing, offers potential opportunities for changing the industry towards more environment friendly industry. In the biological pulping process, removal of lignin can be achieved through treatment of lignocellulosic materials with white rot fungi due to their ability to degrade complex and recalcitrant organic molecules and this makes them attractive micro-organism for biodelignification. In the present study biological pre-treatment of Eucalyptus chips was carried out with Schizophyllum commune. The influence of growth parameters like incubation periods, moisture levels, media, media concentration, pH and temperature were also optimized. During the study it was found that Schizophyllum commune shows 14.72% lignin loss within 28 days at optimum conditions i.e. pH (6.0), temperature (25°C), moisture (60%) and molasses concentration (4%). Thus the study will provide an insight to find out economically feasible conditions to commercialize biopulping on large scale. [ABSTRACT FROM AUTHOR]

Pulp and paper industry is traditionally known to be a large contributor to environmental pollution due its large consumption of energy and chemicals. To reduce the chemical consumption, rate of delignification was increased by Schizophyllum commune in destructured sample of Dendrocalamus stictus, which was destructured by Impressafiner (compression- cum dewatering process). The extent of delignification was determined and comparison was made between the non-destructured and destructured samples. The influence of physical parameters like incubation time, moisture level, media, media concentration, pH and temperature were also examined during the study. It was found that rate of delignification was significantly 6.43% more in destructured sample than non-destructured sample. Kraft pulping of treated destructured sample shows 2.59 point reduction in kappa number than untreated non-destructured sample. Thus this paper provides an insight of the delignification extent in Dendrocalamus strictus after mechanical operation at varying physical parameters. [ABSTRACT FROM AUTHOR]