Oxygen Delignification of Wheat Straw Organosolv Pulp

Authors: HÜSEYİN KIRICI, MUSTAFA USTA, MEHMET AKGÜL

Abstract: In this study, in order to determine optimum conditions for peroxide reinforced oxygen delignification of wheat straw organosolv pulps, five experiments were carried out changing the alkali ratio, peroxide charge and reaction time. After the statistical evaluations of the data obtained, optimum delignification conditions were found to be as follows: NaOH ratio 6%, H_2O_2 ratio 2.5%, reaction temperature 80 ^oC, reaction time 60 min., oxygen pressure 10 kg/cm^2 , concentration 16%. Thus; yield, viscosity and tear index of wheat straw organosolv pulps delignificated with oxygen added peroxide decreased by 18%, 20% and 18% respectively. In addition, residual lignin content of delignified pulp decreased by 60% and brightness, breaking length and burst index of the pulp were found to be respectively 65%, 10% and 52% higher than those of non-delignificated wheat straw organosolv pulps. Consequently, it is concluded that oxygen delignified organosolv pulp has similar strength properties except brightness compared with wheat straw alkaline (soda, soda-oxygen and kraft) pulps.

Keywords: Oxygen Delignification, Wheat Straw, Bleaching, Organosolv Pulping

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