Without reclamation of waste liquor and chemicals recovery, the kraft pulp and paper industry would constitute an enormous pollution problem. Already for economical reasons, substantial recovery is secured, however, and considerable further improvements are foreseen. Recovery is outlined in terms of cycles for sodium, calcium, sulphur, and—in a wider sense—carbon. In addition, the mechanical lo...

K raft pulp is manufactured in the United States from nearly all commercially availble wood species. About 55 million tons per year are manufactured, 30 million of which are bleached and used mostly for printing and office papers and tissue products. Some kraft pulp is exported, and significant quantities are imported, mostly from Canada and South America. Pulps manufact'xed by sulfite, ...

Wood-derived cellulosic fibers prepared in different ways were successfully employed to absorb simulated crude oil, demonstrating their possible use as absorbents in the case of oil spills. When dry fibers were used, the highest sorption capacity (six parts of oil per unit mass of fiber) was shown by bleached softwood kraft fibers, compared to hardwood bleached kraft and softwood chemithermomec...

In this paper, the depolymerization of lignin was successfully achieved by the thermal treatment of kraft lignin in butyl-1,8-diazabicyclo[5.4.0]undec7-enium chloride ([DBUC4][Cl]) without a catalyst. The thermal treatment experiments were performed in an oven at 150, 200, and 250 °C for 1 h. The changes in kraft lignin structure over the course of depolymerization were characterized by gel per...

∈∆N ), (1.1) where the convention 0log(0)= 0 is adapted, (see Shannon [19]). Throughout this paper, ∑ will stand for ∑N i=1 unless otherwise stated and logarithms are taken to the baseD (D > 1). Let a finite set of N input symbols X = {x1, x2, . . . ,xN } be encoded using alphabet of D symbols, then it has been shown by Feinstien [6] that there is a uniquely decipherable code with lengths n1,n2...

Laboratory-obtained kraft lignins have been studied via elemental analysis (EA), 1H-NMR, FTIR, GPC to analyse the chemical structure. The kraft lignins were subjected to oxidation with H2O2 using Co(salen) as a biomimetic catalyst at mild condition (80oC, 240 min). The kraft lignins isolated from eucalyptus (EKL) and bamboo (BKL) had a low hydroxyl (oxygen) contents, a low molecular weights (~3...

Xylans were selectively removed from paper grade pulps by nitren extraction in order to produce dissolving pulps. The impact of nitren charge on the removal of hemicelluloses was demonstrated for a birch and mixed softwood kraft pulp. The 95% purity level could easily be reached for the birch kraft pulp. Softwood glucomannans were almost insoluble under the investigated extraction conditions ap...

raft pulp i s manufactured in the United States from nearly all commercially availK ble wood species. About 55 million tons per year are manufactured, 30 million of which are bleached and used mostly for printing and office papers and tissue products. Some kraft pulp is exported, and significant quantities are imported, mostly from Canada and South America. Pulps manufactldred by sulfite, mecha...

The anatomical structure and chemical composition of the stem-wall material of giant reed is considered from the viewpoint of raw material characterization for industrial fiber production. The effect of stem morphology (nodes and internodes) on pulping results and general pulp properties is discussed. The advantages of application of modern organic solvent based (organosolv) pulping technologie...