This review analyses the advances of pretreatment with sulfide-containing liquors to modify kraft pulping. In the past several decades, modified kraft pulping has advanced rapidly, based on the principle that high sulfide content at the first stage of cooking would improve both pulp quality and the selectivity of delignification. Pretreatment of wood chips with sulfide-containing liquors (i.e.b...

Through the study of forest-pulp enterprise production logistics pulping flow sub-system and production elixir flow sub-system, Petri nets model and the object-oriented model as the theoretical basis, and puts forward the enterprise production logistics subsystem compound model, and discusses the pulping process based on the composite model of logistics balance mathematical principle.

The paper industry has taken various steps to address environmental concerns and raw material limitations. Among them, paper recycling has been shown to be a viable option. In this study, the alkaline sulfite pulping of old corrugated containers (OCC) to produce bleachable pulp was investigated. A combination of one of the three active alkali levels (14, 16, and 18%; Na2O, and oven-dry weight o...

In this paper, the pulping process of wheat straw using ionic liquid 1-ethyl-3-methylimidazolium bromide ([Emim]Br) as the digestion liquor is presented. The influence of pulping conditions on the pulp yield are analysed by single-factor and orthogonal experiments, and optimum pulping conditions are obtained. The average pulp yield reaches 44 %, and the average recovery rate of ionic liquid is ...

At present, microbial and enzymatic preparations for the control of triglyceride-containing pitch deposits during the manufacture of mechanical and sulfite paper is commercially available. However, biotechnological products for pitch control in other pulping processes, such as alkaline pulping, are under development. These products include new fungi for the removal of steroids involved in pitch...

the kinetics of old corrugated container (occ) soda-oxygen delignification was investigated. three delignification temperatures (145,165 and 175ºc) were applied. the pulping duration was adjusted at 150 minutes and the measurements were conducted at 10 minutes intervals. the pulping consistency, oxygen pressure and active alkali were constant at 10%, 6 bar and 18% naoh respectively in all pulpi...

the properties of alkaline sulfite anthraquinone (as/aq) pulp from old corrugated container (occ)was studied. in each trial 100 grams (based on dry weigth) of occ and 18% active alkali was used.three levels of anthraquinone (0.0.1 and 0.2% based on dry weigth of the occ) and two pulpingtimes (120 and 150 minutes at maximum pulping temperature) were applied. pulping temperature,na2so3/naoh ratio...

Sugarcane bagasse was delignified with alkali and peracetic acid in a two-stage process to obtain pulps with high yield and low kappa number. The experimental results indicated that alkali pretreatment prior to peracetic acid (PAA) delignification could significantly reduce PAA loading by partially removing lignin and swelling the fibers. An optimum condition for the two-stage delignification w...