kraft pulp
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2023 ◽  
Vol 83 ◽  
Author(s):  
Y. Huang ◽  
N.-J. Zhang ◽  
Z. Zhao

Abstract As an important enzyme, xylanase is widely used in the food, pulp, and textile industry. Different applications of xylanase warrant specific conditions including temperature and pH. This study aimed to carry out sodium alginate beads as carrier to immobilize previous reported mutated xylanase from Neocallimastix patriciarum which expressed in E. coli, the activity of immobilization of mutated xylanase was elevated about 4% at pH 6 and 13% at 62 °C. Moreover, the immobilized mutated xylanase retained a greater proportion of its activity than the wide type in thermostability. These properties suggested that the immobilization of mutated xylanase has potential to apply in biobleaching industry.


2022 ◽  
pp. 096703352110636
Author(s):  
Payyavula Ramadevi ◽  
Rathinam Kamalakannan ◽  
Ganapathy P Suraj ◽  
Deepak V Hegde ◽  
Mohan Varghese

Measurement of pulpwood traits from a standing tree has considerable advantage when screening large populations for tree selection. It reduces time and also eliminates requirements of transport, powdering, and storing the sample. This study describes estimation of Kraft pulp yield (KPY) in Eucalyptus camaldulensis, E. urophylla, Leucaena leucocephala, and Casuarina junghuhniana by portable NIR spectroscopy of standing trees. Calibration models were developed for KPY estimation using portable NIR spectroscopy for the four species, along with a calibration model for syringyl/guaiacyl (S/G) ratio in E. camaldulensis. The calibration models for KPY showed R2 values ranging from 0.93 ( E. camaldulensis) to 0.83 ( L. leucocephala), and 0.95 for S/G ratio. The developed calibration models for E. camaldulensis and L. leucocephala were compared with laboratory NIR models, and a variation of <±2.0% was found between both methods. The models were validated by both external and cross validation which showed <2.0% RMSEP (root mean square error of prediction) and <2.0% RMECV (root mean square error of cross validation) in external and cross validations, respectively.


2022 ◽  
Author(s):  
Haitang Liu ◽  
Yongzhen An ◽  
Lin Chen ◽  
Xin Jin ◽  
Jing Liu ◽  
...  

Eucalyptus dissolving kraft pulp pre-hydrolysis Liquor (PHL) is rich in sugar and other biomass resources, which can produce furfural and may serve as a platform molecule for sustainable fuel production....


Author(s):  
Ji-Eun Lee ◽  
Na-Young Park ◽  
Do-Hyun Kim ◽  
Do-Young Lee ◽  
Tai-Ju Lee ◽  
...  

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8499
Author(s):  
Igor Cruz ◽  
Magnus Wallén ◽  
Elin Svensson ◽  
Simon Harvey

The recovery and utilisation of industrial excess heat has been identified as an important contribution for energy efficiency by reducing primary energy demand. Previous works, based on top-down studies for a few sectors, or regional case studies estimated the overall availability of industrial excess heat. A more detailed analysis is required to allow the estimation of potentials for specific heat recovery technologies, particularly regarding excess heat temperature profiles. This work combines process integration methods and regression analysis to obtain cogeneration targets, detailed excess heat temperature profiles and estimations of electricity generation potentials from low and medium temperature excess heat. The work is based on the use of excess heat temperature (XHT) signatures for individual sites and regression analysis using publicly available data, obtaining estimations of the technical potential for electricity generation from low and medium temperature excess heat (60–140 °C) for the whole Swedish kraft pulp and paper industry. The results show a technical potential to increase the electricity production at kraft mills in Sweden by 10 to 13%, depending on the level of process integration considered, and a lower availability of excess heat than previously estimated in studies for the sector. The approach used could be adapted and applied in other sectors and regions, increasing the level of detail at which industrial excess heat estimations are obtained when compared to previous studies.


Author(s):  
Klaus Dölle ◽  
Hélène Rainville

Wood relief block printing was developed in China in the seventh century and is used today for many art printing applications. The presented research project describes the development of an art paper product applicable for large wood relief block printing from laboratory scale to large semi commercial production of art paper for printing image sizes of up to 44-inch (1118 mm) by 96-inch (2400 mm) at outdoor steam roller printing events or smaller indoor printing press applications. The improvement of the paper properties from laboratory development, small laboratory paper machine and semi commercial paper machine run for the production of the final art paper showed an improvement throughout the process development for the optical and mechanical paper properties and exceeded the set values set by the artist using the art paper. The produced art paper with a basis weight of 260 g/m² and a thickness of 171 µm is produced from a mixture of 70% northern bleached hardwood Kraft pulp and 30% northern bleached softwood Kraft pulp. The ISO brightness of the art paper off-white (egg-shell) colour was at 63.2% and the ISO color value for L, a, b. at 90.8, 1.1, and 12.6 respectively. The art papers surface roughness and porosity as a parameter for ink attachment and penetration is for the top side 2179 ml/min and for the bottom side (wire side) 2326 ml/min, whereas porosity was measured at 1668 ml/min. Bending stiffness in machine direction and cross machine direction was measured at 157mN and 70 mN respectively. Burst strength was measured at 2.24 kPA·m²/g.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
D. Mandlez ◽  
R. Eckhart ◽  
W. Bauer

Abstract The application of a bench scale and an industrial scale pressure screen to separate cellulosic fines from an unbleached softwood kraft pulp containing 5 % (w/w) primary fines was investigated and the results were compared. In the bench scale trials different microperforated screens with hole diameters of 150 µm, 250 µm, 400 µm and 600 µm were used. Based on these results a screen hole diameter of 400 µm was selected for the industrial scale trials. In all cases, a high accept flow rate proved to be the crucial parameter for high removal efficiency of the fines material and a removal efficiency of well above 50 % could be achieved. Further of interest were the limiting factors regarding increased accept flow rates with a focus on the interrelations between pressure difference, slot velocity and reject consistency. As expected, investigation of electric energy demand showed a correlation between removal efficiency and specific energy consumption, which did not exceed 35 kWh/t(od) feed.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cheol Woo Lee ◽  
Jeong Yong Ryu

Abstract A more efficient application of a dry strength agent (DSA) was investigated to improve the strength of thermomechanical pulp (TMP) blended paper. Strength improvement by DSA application was more effective for hardwood bleached kraft pulp (Hw-BKP) than TMP. The degree of strength improvement of DSA further increased with the increasing degree of refining of Hw-BKP. The strength of the paper was decreased by the fines fractionation of TMP, but the strength improvement efficiency of DSA for the fines fractionated TMP increased. In order to increase the strength of TMP mixed paper using DSA, it is expected that DSA should be adsorbed only to Hw-BKP with high strength improvement efficiency, not TMP fines. When the DSA was mixed with Hw-BKP before contact with other stocks, it was confirmed that the effect of improving the strength by the DSA is the best. The strength improving effect increased as TMP fines were removed. Therefore, to improve the strength of the paper containing TMP in Hw-BKP by adding a DSA, it is preferable to selective apply the DSA to Hw-BKP while blending only the fibers of TMP by fractionation.


2021 ◽  
Vol 947 (1) ◽  
pp. 012023
Author(s):  
Thai Dinh Cuong ◽  
Nguyen Viet Linh ◽  
Nguyen Hoang Chung ◽  
Le Quang Dien

Abstract In this study, the antibacterial bleached hardwood kraft pulp-based paper sheets with a base weight of around 125 g/m2 were made with surface sizing by a mixture of oxidated starch and additives from acetic acid-treated nanochitosan and nanocellulose prepared from limited hydrolysis of rice straw by dilute sulfuric acid with added hydrogen peroxide. The characteristics of nanomaterials were analyzed by SEM and XRD. The barrier and antibacterial properties of paper were investigated to assess their ability to contain liquid and food products. Using the sizing mixture which has a solids content of 8% with additives improved the mechanical strength of the paper. The best value of tearing strength of 18.94 mN.m2/g was obtained with adding of 0.5% of nanocellulose and 1.5% of nanochitosan. The burst index of paper reached its highest value of 5.07 kP.m2/g when both nanocellulose and nanochitosan were used at the dosages of 1.0%. The antibacterial features on E. coli clearly showed in papers with 2% of nanochitosan or with the mixture of 1% nanocellulose and 1% nanochitosan addition.


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