a study was carried out on totally chlorine-free (tcf) bleachability of dimethyl formamide (dmf) treated bagasse pulps exposed to cz-3 and fp 90031-sp strains of white-rot fungus ceriporiopsis subvermispora. this process involved an oxygen and peroxide stage bleaching sequence. the effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...

The fate of lipophilic extractives from several nonwoody species (flax, hemp, sisal and abaca) used for the manufacturing of cellulose pulps, was studied during soda/anthraquinone (AQ) pulping and totally chorine free (TCF) and elemental chlorine free (ECF) bleaching. With this purpose, the lipophilic extracts from the raw materials and their unbleached and bleached industrial pulps, were analy...

We have studied the structural modifications of lignins from sisal and flax during their soda-anthraquinone (AQ) pulping and subsequent totally chlorine-free (TCF) and elementary chlorine-free (ECF) bleaching. For this purpose, residual lignins were isolated from pulps, analyzed by Py-GC/MS, 2D-NMR, and GPC, and their characteristics were compared to the “milled-wood” lignin of the raw material...

A study was carried out on totally chlorine-free (TCF) bleachability of dimethyl formamide (DMF) treated bagasse pulps exposed to CZ-3 and FP 90031-sp strains of white-rot fungus Ceriporiopsis subvermispora. This process involved an oxygen and peroxide stage bleaching sequence. The effect of enzymatic stage on bleachability properties was studied and compared with control pulps, processed witho...

Cellulase-poor crude xylanases of Coprinellus disseminatus, strains SH1 NTCC 1163 (enzyme-A) and SH-2 NTCC 1164 (enzyme-B) produced under optimum conditions of solid-state fermentation (SSF), were used in bio-bleaching of wheat straw soda-AQ pulp in totally chlorine free (TCF) bleaching sequences. Kappa number reductions of 56% and 58% with respect to oxygen-delignified pulps were obtained afte...

oxygen delignified kraft pulp from eucalyptus (e. urophylla × e. grandis) was catalytically pretreated in aerobic condition using ammonium persulfate in present of catalists like cupric acetate and/or cobalt acetate in acetic acid-water solution, i. e. s2o82--cu2+, s2o82--co2+ and s2o82--(cu2++co2+). final bleached pulp after pretreatment with the three catalytic systems showed higher delignifi...

the aim of this work was to study the ability of two biodegradable chelating agents, nitrilotriaceticacid (nta) and ethylenediiminopropanedioic acid (eddm) to complex metals, in the treatment of the pulp,prior to a totally chlorine free (tcf) bleaching process, and compare with the ethylenediaminetetraacetic acid(edta) performance. firstly, speciation efficiency index (sei) was calculated by co...

Free and conjugated sterols are among the main compounds responsible for pitch deposition in the manufacture of wood chemical pulps, making difficult the implementation of totally chlorine free bleaching (TCF) and closure of bleach plant circuits. In this work, the suitability of oxidative enzymes in efficiently removing sterols from eucalypt pulps is revealed. The enzymatic treatment was appli...

To assess the feasibility of implementing hemicellulose recovery stages in kraft mills, Eucalyptus globulus wood samples were subjected to aqueous treatments with hot, compressed water (autohydrolysis processing) to achieve partial dissolution of xylan. Autohydrolyzed solids were subjected to kraft pulping under selected conditions to yield a pulp of low kappa number, and to an optimized TCF bl...