Study On Hydrogen Peroxide And Ammonia Pulping Of Bamboo And Delignification Kinetics

In this paper, study on the technical parameters of pulping by hydrogen peroxide and ammonia with single factor, and finally get the optimal technical parameters of pulping process: hydrogen peroxide charge 9%, ammonia hydrate charge 13%, sodium hydroxide charge 8%, liquor ratio 1:4, maximum temperature is 115℃, time at maximum temperature is 60 min.Adopt this technical parameter for bambusa chungii cooking, and grind the pulp with refiner of 0.5mm,0.3mm,0.15mm interstice, then beat the pulp to 45 SR degree and use the standstard sheet machine to form paper sheet(hand sheet), the physical properties of this hand sheet are :breaking length is 4.85 km, ring crush compression resistance index is 12.95 N·m/g and the tight degree is 0.52g/cm~3, those physical properties have been up to the A class requiremen of national standard of fluting medium (CB13023-91).Delignification mechanism and kinetics of hydrogen peroxide and ammonia pulping of bambusa chungii were studied by pulping experiments carried out under stable and well-defined conditions. Results of study showed that two distinct delignification stages occurred during this pulping process,there are not initial delignification stages ,the bulk delignification stage from beginning of cooking to 115℃for 120 min, It is found that about 78.00% of the lignin is dissolved in the bulk delignification stage.The residual delignification stage at 115℃for 120 min to the cooking end. It is found that about 2.17% of the lignin is dissolved in 90 min. The study of kinetics of hydrogen peroxide and ammonia pulping of Bambusa Chungii showed that two distinct delignification stages, namely, and residual delignification stage, delignification of the two stage were found to be of pseudo first order and activation energy of delignification reaction was 41.12kJ/mol and 50.32kJ/mol respectively.The delignification reactions order of the bulk delignification stage about concentration of sodium hydroxide, hydrogen peroxide and ammonia is 1.28, 0.85, 1.55 respectively, and the delignification reactions order of the residual delignification stage about concentration of sodium hydroxide, hydrogen peroxide and ammonia is 0.98, 0.70, 1.14 respectively.The bulk and the residual delignification stage rate equation of delignification respectively is:...