scholarly journals Operating Experience of the two stage (medium-High-Consistency) Peroxide Bleaching of Mechanical Pulp.

1995 ◽  
Vol 49 (1) ◽  
pp. 135-139
Author(s):  
Kazuhiro Kubo
Keyword(s):  
Operating Experience ◽  
Two Stage ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
High Consistency

scholarly journals Fibre development in an intensified mechanical pulping process

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christer Sandberg
Keyword(s):  
Production Process ◽  
Size Distribution ◽  
Specific Energy ◽  
Microscopic Level ◽  
Mechanical Pulp ◽  
Fibre Properties ◽  
Conventional Process ◽  
Fibre Development ◽  
Printing Paper ◽  
High Consistency

Abstract Mechanical pulp for printing paper can be produced with a process that involve much less equipment and that require much lower specific energy compared to conventional processes. Even though common evaluation methods, e.g. handsheet testing, have shown that the pulp quality is similar for the simplified and the conventional processes, it is not known how fibre properties, at the microscopic level, is developed with the simplified process. In this mill scale study, the fibre properties attained with an “intensified” mechanical pulping process, consisting of single stage high consistency double disc refining followed by two stage low consistency refining and no reject treatment was investigated. The simplified process was compared to a process with a reject system. The simplified process rendered fibres with higher degree of fibrillation, higher share of axial splits, lower fibre wall thickness but slightly lower length than the conventional process. The fibrillar fines size distribution of the two processes was different. The conventional process generated more of small fibrillar fines which probably explains the higher tensile index at given density for that process. The results show that it is possible to simplify the production process for mechanical pulp and reduce the specific energy with over 700 kWh/adt.

Relationship between dissolution of fiber materials and development of pulp strength in alkaline peroxide bleaching of mechanical pulp

Holzforschung ◽  
2004 ◽  
Vol 58 (4) ◽  
pp. 369-375 ◽  
Author(s):  
G.X. Pan
Keyword(s):  
Carboxylic Acid ◽  
Acid Group ◽  
Strength Properties ◽  
Strength Development ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Alkaline Peroxide ◽  
Bonding Properties ◽  
Pulp Strength ◽  
Fiber Materials

Abstract This study elucidates the relationship between the dissolution of pulp components and the development of fiber bonding properties in alkaline peroxide bleaching of aspen mechanical pulp. In general, bleaching reactions cause the removal of pulp substances from the fibers, which in turn improves pulp strength properties. Nonetheless, alkaline hydrolysis is particularly important to the development of strength because this reaction mechanism plays a key role in imparting additional carboxylic acid groups onto the fibers. The strong correlation between fiber carboxylic acid group concentration and the amount of anionic dissolved substances makes it possible for us to predict the strength properties of bleached pulps by estimating the anionicity of bleaching filtrates using analytical methods such as cationic demand. The paper also provides insights into the importance of the alkalinity in peroxide bleaching to the dissolution of pulp materials and the strength development.

Sulfonated Chemi-Mechanical Pulp of Cotton Stalk and Bleaching

2011 ◽  
Vol 291-294 ◽  
pp. 1887-1891
Author(s):  
Shan Shan Liu ◽  
Gui Gan Fang ◽  
Yong Jun Deng ◽  
Qiang Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Treatment ◽  
Physical Property ◽  
Maximum Temperature ◽  
Cotton Stalk ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Operational Variables ◽  
Major Factors ◽  
Cooking Conditions

The influence of operational variables in the Sulfonated Chemi-mechanical pulp (SCMP) of cotton stalk was studied, and the hydrogen peroxide bleaching sequence was carried out. The major factors, such as sulfite sodium charge (calculated as Na2SO33%, 6%, 9%or 12%on oven-dry cotton stalk), active alkali charge (calculated as NaOH 2%, 4%, 6%or 8%on oven-dry cotton stalk) and the maximum temperature (110°C, 130°C or 150°C) was investigated. The result shows that: the pulp physical property was influenced significantly by sulfite sodium and active alkali charge, at an increasing tendency with above factors. The optimal chemical treatment cooking conditions could be proposed as follows: sulfite sodium charge 9%, active alkali charge 2%, maximum temperature 130°C and liquor ratio 4:1. What’s more, the single H2O2bleaching sequence was employed, which can provide pulps with brightness 58.0%ISO.

scholarly journals BICARBONATE ANION AND TAED AS ACTIVATORS IN PEROXIDE BLEACHING OF A MECHANICAL PULP

2020 ◽  
Vol 54 (3-4) ◽  
pp. 319-326
Author(s):  
RAYMOND C. FRANCIS ◽  
◽  
ANTTI LUUKKONEN ◽  
FRANCIS K. ATTIOGBE ◽  
DONATIEN P. KAMDEM ◽  
...  
Keyword(s):  
Mechanical Pulp ◽  
Peroxide Bleaching

The Role of Ferulic Acid Removal during Bleaching of Wheat Straw Mechanical Pulp with Peroxygen Reagents

Holzforschung ◽  
2003 ◽  
Vol 57 (3) ◽  
pp. 282-288 ◽  
Author(s):  
G. X. Pan ◽  
C. I. Thomson ◽  
G. J. Leary
Keyword(s):  
Ferulic Acid ◽  
Wheat Straw ◽  
Model Compounds ◽  
Mechanical Pulp ◽  
Peroxide Bleaching ◽  
Wheat Straw Pulp

Summary The present paper reports our investigation into the use of two peroxygen reagents, peroxymonosulfate (PMS) and dimethyldioxirane (DMD), in bleaching sequences with peroxide to bleach wheat straw mechanical pulp, their reactivity with ferulic acid model compounds, and the likely relation between the two aspects. It was observed that combinations of PMS or DMD with peroxide offered a synergy leading to substantially improved brightness development in bleaching of wheat straw pulp. At the same time, these oxidizing reagents, especially DMD, were shown to be highly reactive with ferulic acid derivatives and increased the removal of ferulic acid from wheat straw pulp in bleaching. The results would suggest that the presence of non-lignin, peroxide-resistant chromophoric components, such as ferulic acid derivatives, might be an important factor limiting the brightness development of wheat straw mechanical pulp by conventional peroxide bleaching.

scholarly journals Operating Experience With a 13,000 SHP, Two Stage, Fluid Cat-Cracker Power Recovery Expander

1984 ◽  
Author(s):  
David H. Linden ◽  
William G. Mathers
Keyword(s):  
High Temperature ◽  
Operating Experience ◽  
Successful Operation ◽  
Two Stage ◽  
Gas Environment ◽  
Critical Components ◽  
Power Recovery

An internal inspection of the expander after 16,000 hours of operation confirmed the successful operation of Ingersoll-Rand’s first two stage, high temperature, FCC expander. This paper discusses the construction and operation of the unit, designed for 1300°F (704°C) dirty gas environment and presents the inspection results of critical components.

Modified hydrogen peroxide bleaching of bamboo chemo-mechanical pulp using aqueous alcohol media

BioResources ◽  
2018 ◽  
Vol 14 (1) ◽  
pp. 870-881
Author(s):  
Fangmin Liang ◽  
Guigan Fang ◽  
Jian Jiao ◽  
Yongjun Deng ◽  
Shanming Han ◽  
...  
Keyword(s):  
Activation Energy ◽  
Hydrogen Peroxide ◽  
Conventional Method ◽  
Value Added ◽  
Aqueous Alcohol ◽  
Mechanical Pulp ◽  
Bleaching Efficiency ◽  
Peroxide Bleaching ◽  
Bleaching Procedure ◽  
Usage Level

The brightness of bleached bamboo chemo-mechanical pulp (CMP) is often too low to be used as a furnish in value-added paper products. In this study, preliminary optimization of various parameters of a modified hydrogen peroxide (H2O2) bleaching procedure for bamboo CMP pulps was performed using the inclusion of ethanol in the bleaching medium (IEBM). Compared with a conventional bleaching method, this modified process is aimed at improving bleaching efficiency and brightness ceiling of bamboo CMP with the proper usage of chemicals. The CMP was bleached to a brightness of 74.2% ISO at the usage level of 12% H2O2, which shows it increased by 7.4% ISO compared with the conventional method. For a brightness target of 72.0% ISO, bleaching with the IEBM method reduced the H2O2 consumption by approximately 60%. In addition, a higher activation energy of H2O2 for the IEBM method was calculated to be 23.3 kJ/mol, which was increased by 3.3 kJ/mol compared with the conventional method.

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