Production of High-Yield Hardwood Pulp by Bisulfite Minimizing the Chlorine Content Cooking
Journal Title: Lesnoy Zhurnal (Russian Forestry Journal) - Year 2021, Vol 8, Issue 3
Abstract
The article presents the results of the development of a technological mode for obtaining bisulfite hardwood pulp of high yield on a magnesium base for the production of various types of containerboard. The reliable and effective chemical and heat recovery technology implemented in the bisulfite method allows to use it in independent sulfite process. The effect of the duration of stay at the final temperature on the pulp yield and kappa number was studied when developing the technological mode of cooking. It was found that the increase in the duration of stay at the final temperature of 160 °C more than 40 min leads to violations of the selectivity of the cooking process. Increasing the duration of stay at the final temperature up to 70 min is accompanied by a decrease in pulp yield by 6 % at a constant value of the kappa number of the semi-finished product. Technological cooking mode: hydromodule 5, SO2 consumption 15.0 %, cooking solution pH 4.3–4.5, impregnation time at 120 °C – 35 min, cooking duration at 160 °C – 40 min. The mode allows to get a semi-finished product with a high yield of 60–65 % with a kappa number of 58–60 units without a hot grinding stage. An assessment of the mechanical strength characteristics of the laboratory samples of bisulfite pulp was carried out in accordance with the standards of the Russian Federation. The obtained values of bursting strength, resistance to flat compression, breaking strength, and breaking stress were comparable with the values of the industrial sample of hardwood neutral sulfite semi-chemical pulp with a semi-finished product yield of 75–78 %. It is shown that the presence of bark in the technological chips in the amount of 7.5 % is accompanied by a decrease in the yield of bisulfite hardwood pulp by 4.5 % and mechanical strength by 7.8 %.
Authors and Affiliations
T. A. Koroleva, L. A. Milovidova, A. A. Dryakhlitsyn
Keywords
Related Articles
- EP ID EP694800
- DOI https://doi.org/10.37482/0536-1036-2021-3-161-169
- Views 163
- Downloads 0
Concentration of Chemical Elements in Larix gmelinii Needles and Betula pendula Leaves
In the Trans-Baikal Territory, mining enterprises significantly pollute the environment with chemical elements. In these conditions, monitoring the state of the environment, including with the help of indicator plants, i...
The Effect of Long-Term Periodic Fertilization on the Structure of the Stand and the Ground Cover in the Cowberry Pine Forests of Middle Taiga (Republic of Karelia)
The results of research on studying the influence of after-effects of periodic nitrogen (N) and complex fertilizer (NPK) treatments on the structure of the tree layer and ground cover are reported. The study objects were...
The Use of Logging Machinery Sets in the Republic of Bashkortostan
The disintegration of the integrated logging enterprises, as well as of the forestry enterprises and the reduced attention of the authorities to the production of specialized machinery and equipment, the logging producti...
Assessment of Natural and Forest Reclaimed Forage Lands in Semi-Desert Conditions in Southern Russia
Haphazard use of pastures has become one of the factors of disturbance of their natural vegetation. Therefore, forest reclamation works were carried out and significant areas of strip plantations of shrubs were created i...
Functional Characteristics of Siberian Spruce Undergrowth Needles under the Canopy and in the Cutting of Bilberry Spruce Forest in the Middle Taiga Subzone
Currently, the coniferous undergrowth preservation in the cuttings of the boreal zone is of great importance for the accelerated restoration of coniferous forests. When assessing the natural regeneration of forests in cl...