Using Neutral Sulfite Semichemical Pulp to Adsorb Lignocelluloses from Prehydrolysis Liquor of the Kraft-based Dissolving Pulp Process

Abstract Cross polarisation/magic angle spinning 13C NMR spectroscopy has been used to study structural changes in cellulose induced by the dissolving pulp process. The cellulose structure in several dissolving pulps was investigated for commercial and laboratory cooked Eucalyptus 92α and 96α. The average lateral dimension, or average thickness, of the cellulose fibril aggregates is related to the amount of surface area exposed and could be one controlling factor for the chemical reactivity of commercial dissolving pulps during modification reactions. The thickness of the cellulose fibril aggregates governs the amount of surface area present in the fibre wall, and cellulose surface material constitutes the part of the cellulose that is directly accessible to reagents. In all sample series investigated, the raw pulp was found to be less aggregated than the corresponding bleached final pulp. Furthermore, an irreversible increase in fibril aggregate width was observed on free drying for both laboratory cooked and commercial pulps. Upon rewetting with water, the freely dried 96α pulp was found to be more aggregated than the freely dried 92α pulp, although sugar analysis showed very similar carbohydrate compositions. As indicated by the molecular mass distribution, the commercial 92α pulp contained larger amounts of degraded cellulose; this may be a plausible explanation for the different behaviour of the 92α and 96α pulps during free drying.

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An integrated process for removing the inhibitors of the prehydrolysis liquor of kraft-based dissolving pulp process via cationic polymer treatment

Biotechnology Progress ◽

10.1002/btpr.1563 ◽

2012 ◽

Vol 28 (4) ◽

pp. 998-1004 ◽

Cited By ~ 11

Author(s):

Abrar Saeed ◽

Pedram Fatehi ◽

Yonghao Ni

Keyword(s):

Cationic Polymer ◽

Dissolving Pulp ◽

Integrated Process ◽

Pulp Process

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Recovering/concentrating of hemicellulosic sugars and acetic acid by nanofiltration and reverse osmosis from prehydrolysis liquor of kraft based hardwood dissolving pulp process

Bioresource Technology ◽

10.1016/j.biortech.2013.12.096 ◽

2014 ◽

Vol 155 ◽

pp. 111-115 ◽

Cited By ~ 48

Author(s):

Laboni Ahsan ◽

M. Sarwar Jahan ◽

Yonghao Ni

Keyword(s):

Acetic Acid ◽

Reverse Osmosis ◽

Dissolving Pulp ◽

Hemicellulosic Sugars ◽

Pulp Process

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Improvement in the Fock test for determining the reactivity of dissolving pulp

TAPPI Journal ◽

10.32964/tj12.11.21 ◽

2013 ◽

Vol 12 (11) ◽

pp. 21-26 ◽

Cited By ~ 39

Author(s):

CHAO TIAN ◽

LINQIANG ZHENG ◽

QINGXIAN MIAO ◽

CHRIS NASH ◽

CHUNYU CAO ◽

...

Keyword(s):

Moisture Content ◽

Sodium Hydroxide ◽

Constant Temperature ◽

Carbon Disulfide ◽

Testing Procedure ◽

Dissolving Pulp ◽

Water Bath ◽

Testing Conditions ◽

Pulp Sample ◽

Fock Reactivity

The Fock test is widely used for assessing the reactivity of dissolving pulp. The objective of this study was to modify the method to improve the repeatability of the test. Various parameters that affect the repeatability of the Fock test were investigated. The results showed that Fock reactivity is dependent on testing conditions affecting the xanthation between cellulose and carbon disulfide, such as the moisture content of the pulp sample, sodium hydroxide (NaOH) concentration, xanthation temperature, carbon disulfide dosage, and xanthation time. The repeatability of the test was significantly improved using the following modified testing procedure: air dried sample in the constant temperature/humidity room, xanthation temperature of 66°F (19°C) in a water bath, xanthation time of 3 h, NaOH concentration of 9% (w/w), and 1.3 mL carbon disulfide.

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