نتایج جستجو برای: pulping
تعداد نتایج: 974 فیلتر نتایج به سال:
The effect of acetosolv pulping variables viz. pulping time, temperature, catalyst (HCl) and acetic acid on oil palm frond fibres was investigated. The following conditions were found to be optimum to pulp frond fibres: 140 oC, 0.5% HCl, 75% acetic acid, and 1/10 solid/liquor ratio. Under these conditions we could obtain these properties: Kappa number 13-16, zero-span tensile breaking length – ...
Cellulosic pulps were prepared from Stellera chamaejasme roots using soda, soda-anthraquinone (soda-AQ), and kraft pulping processes. S. chamaejasme is composed of 73.5% holocellulose, 39.7% α-cellulose, and 17.6% lignin, similar to wheat straw and other non-wood plant materials. The ethanol–benzene extractives content of 9.2% is higher than other non-woods. The conditions used for all pulping ...
Issue: Pulp and paper industry were originally designed and constructed to use virgin wood feedstocks as a raw material. Some of the virgin wood fiber used for the pulp and paper industry is from lower value roundwood logs that are chipped for pulping. The other major source is from the residuals from sawmill, veneer, and lumber plants. These solid wood production plants produce millions of ton...
In order to improve the degradation efficiency of pulping and papermaking wastewater, the combination oxidation process of Fenton with ultrasonic irradiation was carried out. The processes of ultrasonic irradiation alone and Fenton oxidation alone on pulping and papermaking wastewater treatment were optimized respectively. Basing on the optimum process of Fenton oxidation, the synergistic effec...
To reduce the refining energy consumption of chemi-mechanical pulping, treatment with NaOH-thiourea-urea aqueous solution was studied in this work. By means of single-factor experiments, the effects of alkali dosage, soaking time, and freezing time were evaluated. It was found that the optimal conditions were an alkali dosage of 8%, soaking time of 45 min, and freezing time of 105 min. The resu...
The effect of alkaline pulping parameters (temperature, effective alkali (EA) and sulphidity) on the hexenuronic acid (HexA) content of Portuguese Eucalyptus globulus pulps was studied. The HexA content was calculated on a pentosan basis. Unlike softwood pulping, the amount of this acid increased during kraft cooking and only started to decrease in the final stage of delignification (kappa numb...
Waste from pulp and paper mills consist of sugar-rich fractions comprising hemicellulose derivatives and cellulose by-products. A complete characterisation of the waste streams is necessary to study the possibilities of an existing mill. In this work, four chromatographic methods have been developed to obtain the most suitable chromatographic method conditions for measuring woody feedstocks, li...
The chemical composition of lipids from bast fibers of flax (Linum usitatissimum), which are commonly used for high-quality paper pulp production, was thoroughly studied by gas chromatography-mass spectrometry. The main compounds identified were waxes, series of long chain n-fatty alcohols, n-aldehydes, n-fatty acids, and n-alkanes. Free and esterified sterols and triterpenols, steroid hydrocar...
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