Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Determination of Lignin in Wood and Pulp

Radiofrequency (RF) power output levels should be adjusted for a Hartmann-Hahn match. The pulse sequence illustrated in Fig. 4.5.2 should be used with the following parameters  [Pg.152]

td = 2s (seconds) if T,(H) is unknown, or shorter provided td 3T,(H). The value of T,(H) can be estimated in a preliminary experiment by starting with td = 2 s and halving td in successive short runs until signal suppression becomes obvious. [Pg.153]

tp adjusted for a 90° displacement of magnetization. The actual value will depend on RF power and can be estimated by varying tp until null signals are obtained for multiples of 180° displacements. Typical values of tp are a few fis (microseconds). [Pg.153]

tc = 1 ms (millisecond) for relatively weak proton RF field strengths (5 to 10 Gauss) or preferably tc = 2 ms and a stronger field ( 10 Gauss) if the RF power output is available. [Pg.153]

ta = 50 ms if this is within the permissible duty cycle of the spectrometer, or ta 15 ms otherwise. Shorter values can result in noticeable broadening of signals. [Pg.153]

Determination of Lignin in Wood and Pulp by the Acetyl Bromide Method... [Pg.44]

Determination of Acid-Insoluble (Klason) Lignin in Wood and Pulp... [Pg.34]

Colombo P, Corbetta D, Pirotta A, Ruffini G (1962) Chlorine number as a method for evaluation of lignin content of a pulp Pulp Pap Mag Can 63 T126-T140 Effland MJ (1977) Modified procedure to determine acid insoluble lignin in wood and pulp Tappi 60(10) 143-144... [Pg.58]

Determination of Acid-Soluble Lignin in Wood and Pulp Procedure... [Pg.337]

Kolboe and Ellefsen (1962) and Michell et al. (1965) provided preliminary results indicating the feasibility of employing infrared spectroscopy to determine the lignin content of finely ground wood and pulp samples embedded in potassium chloride. Further development and refinement of this technique have led to methods for determination of lignin based on multiple internal reflectance infrared spectrometry (Marton and Sparks 1967) and diffuse reflectance Fourier transform spectrometry (Schultz et al. 1985). Lignin contents have also estimated by 13C CP/MAS/NMR spectrometry (Haw et al. 1984, Hemmingson and Newman 1985) (see Chap. 4.5). [Pg.43]

Berzins V (1965) A rapid procedure for the determination of kappa number Tappi 48 15-20 Berzins V (1966) Micro-kappa numbers Pulp Pap Mag Can 67 T206-T208 Bethge PO, Gran G, Ohlsson K-E (1952) Determination of lignin in chemical wood pulp I Principles and methods Sven Papperstidn 55 44-48 Bihkova A (1973) Verification of analytical methods for the determination of lignin in water Vodm Hospod 23(2) 44, Abstr Bull Inst Pap Chem 48 1245 Birkett MD, Gambino MJT (1989) Estimation of pulp kappa number with near-infrared spectroscopy Tappi J 72(9) 193-197... [Pg.58]

Loras V, Loschbrandt F (1956) Gravimetric and absorptiometric determination of lignin in pulp and wood Nor Skogind 10 1-12... [Pg.60]

Occurrence, formation, structure and reactions. Wiley-Interscience, New York, 511-573 Andersson S-I, Samuelson O (1985) Formation of soluble compounds during pretreatment of kraft pulp with nitrogen dioxide. Sven Papperstidn 88 R102-R104 Bagby MO, Nelson GH, Helman EG, Clark EF (1971) Determination of lignin in non-wood plant fiber sources. Tappi 54 1876-1878... [Pg.327]

The lignin contents of P radiata and E regnans woods and pulps determined by the standard Klason method and by the conventional and modified acetyl bromide methods are listed in Table 2 2 4 The lignin contents determined using the modified procedure generally agree better with those obtained by the Klason method than do results obtained using the conventional acetyl bromide method... [Pg.47]

Schoning AG, Johansson G (1965) Absorptiometric determination of acid-soluble lignin in semichemical bisulfite pulps and in some woods and plants Sven Papperstidn 68 607-613 Schultz TP, Templeteon MC, McGinnis GD (1985) Rapid determination of lignocellulose by diffuse reflectance Fourier transform infrared spectrometry Anal Chem 57 2867- 2869 Sjostrom E, Enstrom B (1966) Spectrophotometnc determination of the residual lignin in pulp after dissolution in cadoxene Sven Papperstidn 69 469-476... [Pg.60]

Musha Y, Goring DAI (1975) Distribution of synngyl and guaiacyl moieties in hardwoods as indicated by ultraviolet microscopy Wood Sci Technol 9 45-58 Parham RA (1974) Distribution of lignin in kraft pulp as determined by electron microscopy Wood Sci Technol 6 305-315... [Pg.144]

Westermark U, Lidbrandt O, Eriksson I (1988) Lignin distribution in spruce (Picea abies) determined by mercurization with SEM-EDXA technique. Wood Sci Technol 22 243-250 Whiting P, Goring DAI (1982) Chemical characterization of tissue fractions from the middle lamella and secondary wall of black spruce tracheids. Wood Sci Technol 16 261-267 Wood JR, Goring DAI (1971) The distribution of lignin in stem wood and branch wood of Douglas-fir. Pulp Pap Mag Can 72 T95-T102... [Pg.145]

See other pages where Determination of Lignin in Wood and Pulp is mentioned: [Pg.69]    [Pg.34]    [Pg.152]    [Pg.32]    [Pg.91]    [Pg.69]    [Pg.34]    [Pg.152]    [Pg.32]    [Pg.91]    [Pg.40]    [Pg.35]    [Pg.17]    [Pg.37]    [Pg.48]    [Pg.59]    [Pg.457]    [Pg.39]    [Pg.336]    [Pg.347]    [Pg.542]    [Pg.374]    [Pg.33]    [Pg.110]    [Pg.50]    [Pg.19]    [Pg.33]    [Pg.38]    [Pg.40]    [Pg.40]    [Pg.43]    [Pg.43]    [Pg.110]    [Pg.29]   


SEARCH



Determination of Acid-Soluble Lignin in Wood and Pulp

Determination of Lignin in Wood and Pulp by the Acetyl Bromide Method

Lignin in wood

Lignins determination

Of lignin

Of woods

Pulping of wood

Wood and Lignin

Wood lignin

Wood pulp

Wood pulping

© 2024 chempedia.info