Document Type : Research Paper

Authors

1 Young Researchers and Elite Club, Karaj Branch, Islamic Azad University

2 Department of Pulp and Paper Industries, Gorgan University of Agricultural Sciences and Natural Resources

Abstract

In conducting environmentally friendly processes for pulp production, first step is to reduce the effluent pollution load in each stage, and because the bleaching process is the most polluting stage in the production of pulp, improving it is one of the most important matters. The first act to ameliorate bleaching process of chemical pulps is the reduction of colored materials, mostly lignin, which enter to the bleaching section. Thus, the use of oxygen delignification stage after pulping and before bleaching process is the key stage in improving process and cleaner production. In this study, the effect of conducting oxygen-delignifying treatment by two kinds of machines, and under different process condition, on chemical, physical, mechanical and optical properties of bagasse soda pulp was investigated. The bagasse soda pulp with the kappa number of 20, 955 ml/g viscosity, and 37% ISO brightness was prepared from Pars Hafttapeh Company. Oxygen-delignifying treatments were carried out with three different temperatures of 90, 100 and 110°C, and two oxygen pressures of 5 and 7 bars, with and without magnesium sulfate addition, by two kinds of machines. Results indicated that oxygen delignification treatment led to intense decrease in pulp kappa number, while the pulp viscosity did not change. Results of measuring delignified pulp viscosity showed that the magnesium sulfate addition caused to prevention of pulp viscosity downfall. The increase in reaction temperature had a significant effect on the process improvement, but raising the oxygen pressure did not have a meaningful effect on the process. The pulp brightness was increased about 4-6%. And also, due to the need of shorter time in order to reach the reaction temperature in the Iranian made machine, pulp delignifying by this machine was a little lower than Quantum machine.

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-Bajpai, P., 2005. Environmentally Benign Approaches for Pulp Bleaching, In: Developments in environmental management. Elsevier, Netherlands, 277p.
-Basta, J., Holtinger, L., and Hook, J., 1991. Controlling the Profile of Metals in the Pulp before Hydrogen Peroxide Treatment. In Proceedings of 6th ISWPC, April 30-May 4: 237-244.
-Basta, J., Wane, G., Herstad-Svard, S., Lundgren, P., Johansson, N., Edwards, L., and Gu, Y., 1998. Partial closure in modern bleaching sequences. Tappi Journal, 81(4): 136-140.
-Berggren, R., 2003. Cellulose degradation in pulp fibers studied as changes in molar mass distributions. Ph.D. thesis, Department of Fibre and Polymer Technology, Royal Institute of Technology, Stockholm.
-Biermann, C.J., 1996. Handbook of pulping and papermaking. Elsevier, London, 778p.
-Hart, P.W., Mancosky, D., and Armstead, D., 2006. Medium consistency oxygen delignification performed with a controlled cavitation reactor. Tappi Journal, 5(2): 13-19.
-Hostachy, J.C., 2009. Bagasse pulp bleaching with ozone “It’s Time to Implement Green Bleaching Practices”, 9p.
-Iakovlev, M., 2011. SO2-ethanol-water (SEW) fractionation of lignocellulosics. Ph.D. thesis, Department of Forest Products Technology, Aalto University, Helsinki.
-Johnson, B., 2008. Literature Review of Colour Reduction Technologies for Kraft Pulp Mill Effluent. By Beca AMEC Limited, 38p.
-Johnson, A.P., Johnson, B.I., Gleadow, P., Araneda, H., Silva, F.A., Aquilar, R.M., and Hsiang, C.J., 2008. 21st Century Fibrelines. International Bleaching Conference, Quebec City, 2-5 June, 15-28.
-Khristova, P., Kordsachia, O., Patt, R., Khider, T., and Karrar, I., 2002. Alkaline pulping with additives of kenaf from Sudan. Industrial Crops and Products, 15, 229-235.
-Liu, J., Hu, H., and Luo X., 2012. Development of a novel empirical model to estimate the kraft pulp yield of fast-growing eucalyptus. BioResources, 7(1): 1134-1144.
-Lucia, L.A., and Jameel, H., 2006. High Selectivity Oxygen Delignification. Institute of Paper Science and Technology, Georgia Institute of Technology, Atlanta.
-Mohta. D., Kapoor, S.K., and Ray, A.K., 1998. Environmentally Friendly Pulping and Bleaching of Bagasse. University of Roorkee, Saharanpur-247 001, U.P., India.
-Mohta. D., Upadhaya, J.S., Kapoor, S.K., Roy, A.K., and Roy, D.N., 1998. Oxygen Delignification of Soda and Soda-AQ Bagasse Pulps. Tappi 81(6): 184-187.
-Saraeian, A.R., and Khalili, A., 2013. Technology of pulp production by kraft process. Ayij, Tehran, 306p.
-Seth, R.S., 2006. The importance of fibre straightness for pulp strength. Journal of Pulp & Paper Canada, 107(1): 34-42.
-Sihtola, H., Kyrklund, B., Laamanen, L., and Palenius, I., 1963. Comparison and Conversion of Viscosity and DP-Values Determined By Different Methods. Paperi ja Puu, 45, 225-232.
-Singh, R.P., 1991. The bleaching of pulp. TAPPI Press, Atlanta, 694p.
-Sixta, H., 2006. Handbook of pulp. Strauss GmbH, Morlenbach, 1352p.
-Smook, G.A., 1992. Handbook for Pulp & Paper Technologists. Vancouver, 419p.
-Suess, H.U., 2010. Pulp bleaching today. Walter de Gruyter GmbH & Co. KG, Berlin/New York, 310p.
-Sundberg, A., Sundberg, K., Lilland, C., and Holmbom, B., 1996. Determination of hemicelluloses and pectins in wood and pulp fibres by acid methanolysis and gas chromatography, Nordic Pulp and Paper Research Journal, 11(4): 216-219.
-Tao, L., Genco, J.M., Cole, B.J.W., and Fort, R.C., 2011. Selectivity of oxygen delignification for southern softwood kraft pulps with high lignin content. Tappi Journal, 83(1): 29-39.
-TAPPI, 2006-2007. TAPPI Test Methods, TAPPI. Norcross, GA 30092 USA.
-Teleman, A., Harjunpaa, V., Tenkanen, M., Buchert, J., Hausalo, T., Drakenberg, T., and Vuorinen, T., 1995. Characterisation of 4-deoxy-beta-L-threo-hex-4-enopyranosyluronic acid attached to xylan in pine kraft pulp and pulping liquor by 1H and 13C NMR spectroscopy. Carbohydrate Research, 272(1): 55-71.
-Walford, S.N., 2008. Sugarcane bagasse: how easy is it to measure its constituents? Proceedings of the South African Sugar Technologists Association, 81, 266-273.
-Walker, J.C.F., 2006. Primary wood processing: Principles and practice. Springer, Dordrecht, 606p.
-World Bank, 1998. Pollution prevention and abatement Handbook: Pulp and Paper mills. Draft technical background document. Environment Department, Washington, D.C., 395-400.
-Zeinaly, F., Shakhes, J., Dehghani, M., & Shakeri, A., 2009. Hydrogen peroxide bleaching of CMP pulp using magnesium hydroxide. Bioresources, 4(4): 1409-1416.