Lignin, cellulosics

Consid - the Kraft pulping process shown in Fig. 8.8 (Dunn and El-Halwa, 1993). The first step in the process is digestion in which wood chips, containing primarily lignin, cellulose, and hemicellulose, are cooked" in white liquor (NaOH, Na2S, Na2C03 and... 

Holzfaser, /. wood fiber, ligneous fiber wood pulp = Holzfaserstoff. -papier, n. wood-pulp paper, -stoff, m. lignin cellulose lignocellulose. 

Pulp and paper Washington operations Phenols, organic sulfur compounds, oils, lignins, cellulose... 

The support for a chemical linkage between cellulose and lignin in wood, presented by Hibbert and co-workers (90), is based on their treatment of oak wood with acetic anhydride, glacial acetic acid and catalytic amounts of sulfuric acid. A fraction soluble in dioxane was found to have, after several precipitations, the same composition of lignin, cellulose and pentosan as that of the wood itself. 

J. E. Courtois, C. Chararas, M. M. Debris, and H. Laurant-Hube, Symp. Intern. Chim. Biochim. Lignine, Cellulose, Hemicelluloses, Grenoble (1964). 

Wood is composed approximately of cellulose and lignin. Cellulose is a multiple alcohol of schematic formula (H-C-0-H)n so... 

Figure 1.15 gives an overview of the main constituents of non food biomass. There are three components Cellulose, hemicellulose and lignin. Cellulose and hemicellulose are built form sugar-type monomers, but their cost-effective isolation through enzymatic depolymerization remains a challenge. 

Another approach to produce chemicals via degraded molecules is the fast pyrolysis of biomass at high temperatures in the absence of oxygen. This gives gas, tar and up to 80 wt.% of a so-called bio-oil liquid phase, which is a mixture of hundreds molecules. Some of compounds produced by pyrolysis have been identified as fragments of the basic components of biomass, viz. lignin, cellulose and hemicellulose. The bio-oil composition depends upon the nature of starting... 

Ramiah, M.V. and Goring, D.A.I. (1967). Some dilatomeric measurements of the thermal decomposition of cellulose, hemicellulose and lignin. Cellulose Chemistry and Technology, 1(3), 277-285. 

Extraction of the cellulase system. The culture of SSF from each flask (originally 5 g of substrate) was mixed well with more water to bring the final weight of the mixture (mycelium plus unutilized lignin, cellulose, and hemicelluloses) to 100 g. Tween 80 was added at a rate of 0.1%. The mixture was shaken for 0.5 h and centrifuged. The supernatant was used for enzyme determination. We estimated that about 7% to 10% cellulases remained adsorbed on the residues (mycelium and unutilized cellulose, hemicelluloses, and lignin) when the residues were suspended in water and Tween 80 as before and the supernatant was tested for cellulase titer. 

Some clues may be available from studies of the decomposition of lignin. Lignin constitutes the second most abundant carbon polymer on earth after cellulose (46). The understanding of biodegradative pathways of lignin and lignin-cellulosic polymers may elucidate the problems of reduced plant productivity associated with surface residues in conservation production systems. 

Other extraction procedures are used for determining (i) oils, fats and waxes (ii) fibre, lignin, cellulose, nitrogen-free extract and starch (iii) in vitro... 

Fibre, lignin, cellulose, nitrogen-free extract and starch... 

Instead of predicting the ME value of silage from the MADE measurement using a regression equation (see Chapter 4, Fibre, lignin, cellulose. 

Cellophane is, after chemical modification, obtained from the cellulose in wood, just as paper (from cellulose and lignin), cellulose fibres ( rayon ), and cellulose plastics. Leather is made from animal hides in a tanning process. 

China Quercus acutissima Carr. Q. dentata Thunb. Q. liaotungensis Koidz. Q. mongolica Fisch. ex Turcz. Q. variabilis Blume Lignin, cellulose, protein, pentosan, galactan.56 Promote absorption of tuberculous nodules, remedy for diarrhea, hypertrophy of the gastrointestinal tract, root makes a cleansing dressing for foul sores. 

The wall material of plant cells is one of their distinguishing characteristics. As a result, lignin, cellulose, and other wall constituents have been studied in many plant tissue cultures. Phenylpropanoids. for example, have been shown lo be precursors of lignin formation in while pine. Set/noiii. lilac, rose, carrot, and geranium tissue cultures. Moreover, the biosynthesis of lignin has been shown to be alTeeted by kinetin. boron, and major elements, such as calcium. 

Ericsson, B., Nist, B., Sarkanen, K. V., Chim. Biochim. Lignine, Cellulose, He mi celluloses, Actes Symp. Intern., Grenoble, France 1964, p. 59. 

The difficulty encountered in separating lignin from the cellulose of wood without the intermediate use of hydrolytic conditions,43 as well as the fact that some workers have isolated uniform, lignin-cellulose complexes,44 has suggested the presence of a carbohydrate-lignin compound. 

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